309 Sentences With "innervate" | Random Sentence Generator

We're interested in the sensory neurons that innervate the skin.

There, nerves that once commanded her hand and forearm—remnants of her amputation—now innervate her biceps and triceps muscles.

Both systems, he adds, innervate a muscle called the trigone at the neck of the bladder that controls its contractions, so disrupting these systems can prevent your bladder from pushing pee out.

There is similar somatotopy associated with α-MNs that innervate flexor and extensor muscles: α-MNs that innervate flexors tend to be located in the dorsal portion of lamina IX; those that innervate extensors tend to be located more ventrally.

The hair cells thus respond by stimulating neurons that innervate them.

These ganglia contain neurons whose postganglionic axons innervate the stomach, liver, gallbladder, spleen, kidney, small intestine, and the ascending and transverse colon. They directly innervate the ovarian theca and secondary interstitial cells and exert an indirect action on the luteal cells.

Lesions of the dorsomedial nucleus almost completely eliminate the circadian rhythm of sleep. GABAergic neurons in the dorsomedial nucleus innervate the VLPO, and glutamatergic neurons innervate the lateral hypothalamus, suggesting that the dorsomedial nucleus mainly promotes wakefulness during the active period (daytime for humans).

Chitons lack a clearly demarcated head; their nervous system resembles a dispersed ladder. No true ganglia are present, as in other molluscs, although a ring of dense neural tissue occurs around the oesophagus. From this ring, nerves branch forwards to innervate the mouth and subradula, while two pairs of main nerve cords run back through the body. One pair, the pedal cords, innervate the foot, while the palliovisceral cords innervate the mantle and remaining internal organs.

Beta motor neurons innervate intrafusal fibers of muscle spindles. These nerves are responsible for signaling slow twitch muscle fibers.

Small branches of the buccal nerve innervate the lateral pterygoid muscle. It also gives sensory branches to the cheek.

The deep temporal nerves, are two branches of the anterior division of the mandibular nerve that innervate the temporalis.

Henneman’s size principle describes relationships between properties of motor neurons and the muscle fibers they innervate and thus control, which together are called motor units. Motor neurons with large cell bodies tend to innervate fast-twitch, high-force, less fatigue-resistant muscle fibers, whereas motor neurons with small cell bodies tend to innervate slow-twitch, low-force, fatigue-resistant muscle fibers. In order to contract a particular muscle, motor neurons with small cell bodies are recruited (i.e. begin to fire action potentials) before motor neurons with large cell bodies.

The dorsal nerve of the clitoris is a nerve in females that branches off the pudendal nerve to innervate the clitoris.

Vagal afferents expressing GPR65 innervate intestinal villi. These GPR65-expressing vagal afferents detect nutrients in the intestinal lumen and also slow gut motility.

Alpha (α) motor neurons (also called alpha motoneurons), are large, multipolar lower motor neurons of the brainstem and spinal cord. They innervate extrafusal muscle fibers of skeletal muscle and are directly responsible for initiating their contraction. Alpha motor neurons are distinct from gamma motor neurons, which innervate intrafusal muscle fibers of muscle spindles. While their cell bodies are found in the central nervous system (CNS), α motor neurons are also considered part of the somatic nervous system—a branch of the peripheral nervous system (PNS)—because their axons extend into the periphery to innervate skeletal muscles.

A neuroeffector junction is a site where a motor neuron releases a neurotransmitter to affect a target—non-neuronal—cell. This junction functions like a synapse. However, unlike most neurons, somatic efferent motor neurons innervate skeletal muscle, and are always excitatory. Visceral efferent neurons innervate smooth muscle, cardiac muscle, and glands, and have the ability to be either excitatory or inhibitory in function.

Given the wide area that the many serotonergic neurons innervate, these pathways are implicated in many functions, as listed above. The caudal serotonergic nuclei heavily innervate the spinal cord, medulla and cerebellum. In general, manipulation of the caudal nuclei(e.g. pharmacological, lesion, receptor knockout) that results in decreased activity decreases movement, while manipulations to increase activity cause an increase in motor activity.

The superior ganglion contains neurons which innervate some of the dura mater lining the posterior cranial fossa via the meningeal branch of the vagus nerve.

When administered topically, the intended targets for zucapsaicin are the neurons that innervate the local area of application. These neurons transmit pain toward the CNS.

Muscle spindles are innervated by both sensory neurons and motor neurons in order to provide proprioception and make the appropriate movements via firing of motor neurons. There are three types of lower motor neurons involved in muscle contraction: alpha motor neurons, gamma motor neurons, and beta motor neurons. Alpha motor neurons, the most abundant type, are used in the actual force for muscle contraction and therefore innervate extrafusal muscle fibers (muscle fibers outside of the muscle spindle). Gamma motor neurons, on the other hand, innervate only intrafusal muscle fibers (within the muscle spindle), whereas beta motor neurons, which are present in very low amounts, innervate both intrafusal and extrafusal muscle cells.

Instead, they synapse at the inferior mesenteric ganglion and innervate the smooth muscle lining the large intestines, kidney, bladder, glands of the hindgut, and pelvic viscera.

Studies have found that use of certain drugs (e.g., cocaine) affect cholinergic neurons that innervate the reward system, in turn affecting dopamine signaling in this region.

The somatic part consists of the nerves that innervate the skin, joints, and muscles. The cell bodies of somatic sensory neurons lie in dorsal root ganglia of the spinal cord. The visceral part, also known as the autonomic nervous system, contains neurons that innervate the internal organs, blood vessels, and glands. The autonomic nervous system itself consists of two parts: the sympathetic nervous system and the parasympathetic nervous system.

Trigeminal nerves which innervate specialized temperature sensitive receptors on the nose-leaf may in turn activate TRPV1-S channels in the TG in response to infrared thermal radiation.

This region is designated lamina IX in the Rexed lamina system, which classifies regions of gray matter based on their cytoarchitecture. Lamina IX is located predominantly in the medial aspect of the ventral horn, although there is some contribution to lamina IX from a collection of motor neurons located more laterally. Like other regions of the spinal cord, cells in this lamina are somatotopically organized, meaning that the position of neurons within the spinal cord is associated with what muscles they innervate. In particular, α-MNs in the medial zone of lamina IX tend to innervate proximal muscles of the body, while those in the lateral zone tend to innervate more distal muscles.

Motor neurons are located in the ventral horn of the spinal cord and the brainstem. These neurons innervate skeletal muscle fibers through the propagation of action potentials down their axons (through ventral roots and cranial nerves), and they stimulate skeletal muscle fibers at neuromuscular junctions where they synapse with the motor end plates of muscle fibers. In humans, these axons can be as long as one meter. Motor neurons themselves fall into three main classes: alpha-motor neurons control extrafusal muscle fibers, meaning that they innervate skeletal muscles leading to movement; gamma-motor neurons innervate intrafusal muscle fibers, controlling the sensitivity of muscle spindles to stretch; beta-motor neurons are capable of synapsing on either type of muscle fiber.

C fibers that carry nociceptive signals can be divided into two types: fibers that contain neuropeptides, like substance P, and fibers that do not contain neuropeptides. The two types terminate in very different areas. Non-peptidergic C fibers are linked to the skin, where they innervate the epidermis while peptidergic C fibers innervate other tissues and deeper parts of the skin. There are two main types of nociceptive signals: sensory and affective.

The auditory nerve fibres, known as the afferent nerve fibres, carry information from the organ of Corti to the brainstem and brain. Auditory afferent fibres consist of two types of fibres called type I and type II fibres. Type I fibres innervate the base of one or two inner hair cells and Type II fibres innervate the outer hair cells. Both leave the organ of Corti through an opening called the habenula perforata.

The trigeminovascular system consists of neurons in the trigeminal nerve that innervate cerebral blood vessels. It has been hypothesized that the trigeminovascular system may be involved in some types of headaches.

Afferent neurons innervate cochlear inner hair cells, at synapses where the neurotransmitter glutamate communicates signals from the hair cells to the dendrites of the primary auditory neurons. There are far fewer inner hair cells in the cochlea than afferent nerve fibers – many auditory nerve fibers innervate each hair cell. The neural dendrites belong to neurons of the auditory nerve, which in turn joins the vestibular nerve to form the vestibulocochlear nerve, or cranial nerve number VIII.Meddean – CN VIII.

The medial clunial nerves innervate the skin of the buttocks closest to the midline of the body. Those nerves arise from the posterior rami of sacral spinal nerves (S1, S2, and S3).

The facial nerve carries axons of type GSA, general somatic afferent, to skin of the posterior ear. The facial nerve also carries axons of type GVE, general visceral efferent, which innervate the sublingual, submandibular, and lacrimal glands, also mucosa of nasal cavity. Axons of type SVE, special visceral efferent, innervate muscles of facial expression, stapedius, the posterior belly of digastric, and the stylohyoid. The axons of type SVA, special visceral afferent, provide taste to the anterior two-thirds of tongue via chorda tympani.

The facial motor nucleus is a collection of neurons in the brainstem that belong to the facial nerve (cranial nerve VII). These lower motor neurons innervate the muscles of facial expression and the stapedius.

Furthermore, QST is limited by a patient's subjective experience of pain sensation. Quantitative sudomotor axon reflex testing (QSART) measures sweating response at local body sites to evaluate the small nerve fibers that innervate sweat glands.

The inferior clunial nerves (also called gluteal branches of posterior femoral cutaneous nerve) innervate the skin of the lower part of the buttocks. They arise as branches of the posterior cutaneous nerve of the thigh.

It supplies motor innervation to iliopsoas, pectineus, sartorius, and quadriceps; and sensory branches to the anterior thigh, medial lower leg, and posterior foot. The nerves of the sacral plexus pass behind the hip joint to innervate the posterior part of the thigh, most of the lower leg, and the foot. The superior (L4-S1) and inferior gluteal nerves (L5-S2) innervate the gluteus muscles and the tensor fasciae latae. The posterior femoral cutaneous nerve (S1-S3) contributes sensory branches to the skin on the posterior thigh.

The superior ganglion contains neurons which innervate the concha of the auricle, the posteroinferior surface of the external auditory canal and posteroinferior surface of the tympanic membrane all via the auricular branch of the vagus nerve.

These neurons are electrically coupled with motoneurons which innervate extraocular, jaw and opercular muscles and mediate pectoral fin adduction in hatchetfish. This component of the neural circuit was first described by Michael V.L. Bennett and colleagues.

Rebecca Gregory: "The value of place-names as evidence for the history, landscape and language(s) of a chosen area", Innervate, Vol. 4 (2011–2012). Retrieved 14 October 2019. Lord and tenant-in-chief was Geoffrey Alselin.

Regardless of the fact that there is a technical difference, many professionals use the terms interchangeably. This is because without regeneration, there would not be a nerve to innervate, but without reinnervation, the nerve would not function.

The role of these nerves is to innervate the skin (somatic fibers) and help control autonomic function (autonomic fibers). It is estimated that 15–20 million people in the United States have some form of peripheral neuropathy.

Neurons of the collateral ganglia, also called the prevertebral ganglia, receive input from the splanchnic nerves and innervate organs of the abdominal and pelvic region. These include the celiac ganglia, superior mesenteric ganglia, and inferior mesenteric ganglia.

The neurons in the inferior ganglion of the vagus nerve are pseudounipolar and provide sensory innervation (general somatic afferent and general visceral afferent). The axons of the neurons which innervate the taste buds of the epiglottis synapse in the rostral portion of the solitary nucleus (gustatory nucleus). The axons of the neurons which provide general sensory information synapse in the spinal trigeminal nucleus. The axons of the neurons which innervate the aortic bodies, aortic arch, respiratory and gastrointestinal tract, synapse in the caudal part of the solitary nucleus.

Static gamma motor neurons innervate static nuclear bag fibers (bag2 fibers), a type of nuclear bag fiber and nuclear chain fibers. Both of these fiber types are part of the intrafusal muscle spindle fibers, where the static gamma motor neurons innervate onto. Nuclear chain fibers' nuclei are organized in longitudinal columns, which is where it gets its name from, whereas the nuclear bag fibers' nuclei are clumped in the midsection of the muscle spindle. There is approximately a 2:1 ratio of nuclear chain fibers to nuclear bag fibers.

Type II neurons on the other hand innervate outer hair cells. However, there is significantly greater convergence of this type of neuron towards the apex end in comparison with the basal end. A 1:30-60 ratio of innervation is seen between Type II neurons and outer hair cells which in turn make these neurons ideal for electromechanical feedback. Type II neurons can be physiologically manipulated to innervate inner hair cells provided outer hair cells have been destroyed either through mechanical damage or by chemical damage induced by drugs such as gentamicin.

The sensory function of the trigeminal nerve is to provide tactile, proprioceptive, and nociceptive afference to the face and mouth. Its motor function activates the muscles of mastication, the tensor tympani, tensor veli palatini, mylohyoid and the anterior belly of the digastric. The trigeminal nerve carries general somatic afferent fibers (GSA), which innervate the skin of the face via ophthalmic (V1), maxillary (V2) and mandibular (V3) divisions. The trigeminal nerve also carries special visceral efferent (SVE) axons, which innervate the muscles of mastication via the mandibular (V3) division.

A motor pool consists of all individual motor neurons that innervate a single muscle. Each individual muscle fiber is innervated by only one motor neuron, but one motor neuron may innervate several muscle fibers. This distinction is physiologically significant because the size of a given motor pool determines the activity of the muscle it innervates: for example, muscles responsible for finer movements are innervated by motor pools consisting of higher numbers of individual motor neurons. Motor pools are also distinguished by the different classes of motor neurons that they contain.

The SN is at first associative. This is confirmed by the effects of striatal stimulations.Kitano et al., 1998 All the projections from the primary somatosensory cortex to the putamen, avoid the striosomes and innervate areas within the matrix.

The superior cluneal nerves innervate the skin of the upper part of the buttocks. They are the terminal ends of the T12-L3 spinal nerve posterior rami lateral branches.Trescot, Andrea.2016."Peripheral Nerve Entrapments -- Clinical Diagnosis and Management."Springer.

Thermoreceptors can be separated into two groups for warmth and cold detection. A subset of unmyelinated fibers are responsible for warmth detection. They are mechano-insensitive, low in number, and innervate small receptive fields. Aδ fibers are responsible for cold detection.

MSO determines the angle the sound came from by measuring time differences in left and right info. LSO normalizes sound levels between the ears; it uses the sound intensities to help determine sound angle. LSO innervates the IHC. VNTB innervate OHC.

In addition to receiving neurotrophic factors from muscles, α-MNs also secrete a number of trophic factors to support the muscle fibers they innervate. Reduced levels of trophic factors contributes to the muscle atrophy that follows an α-MN lesion.

A three-phase model is the classical view of the respiratory CPG. The phases of the respiratory CPG are characterized by the rhythmic activity of: (1) the phrenic nerve during inspiration; (2) recurrent laryngeal nerve branches that innervate the thyroarytenoid muscle during the last stage of expiration; (3) the internal intercostal nerve branches that innervate the triangularis sterni muscle during the second stage of expiration. The rhythmicity of these nerves is classically viewed as originating from a single rhythm generator. In this model, phasing is produced by reciprocal synaptic inhibition between groups of sequentially active interneurons.

The cingulate gyrus and the amygdala also innervate the LC, allowing emotional pain and stressors to trigger noradrenergic responses. The cerebellum and afferents from the raphe nuclei also project to the LC, in particular the pontine raphe nucleus and dorsal raphe nucleus.

This plexus innervates the pectoral girdle and upper limb. The lumbar plexus contains ventral rami from spinal nerves L1-L4. The sacral plexus contains ventral rami from spinal nerves L4-S4. The lumbar and sacral plexuses innervate the pelvic girdle and lower limbs.

The postganglionic axons of the SCG innervate the pineal gland and are involved in Circadian rhythm. This connection regulates production of the hormone melatonin, which regulates sleep and wake cycles, however the influence of SCG neuron innervation of the pineal gland is not fully understood.

Gamma motor neurons innervate intrafusal muscle fibers that control the sensitivity of muscle spindles to stretch. They have smaller cell bodies than alpha motor neurons and do not receive proprioceptive input. They have been shown to reduce in numbers but not size with age.

Parasympathetic ganglia are the autonomic ganglia of the parasympathetic nervous system. Most are small terminal ganglia or intramural ganglia, so named because they lie near or within (respectively) the organs they innervate. The exceptions are the four paired parasympathetic ganglia of the head and neck.

GTOs' inhibitory effects come from their reflex arcs: the Ib sensory fibers that are sent through the dorsal root into the spinal cord to synapse on Ib inhibitory interneurons that in turn terminate directly on the motor neurons that innervate the same muscle. The fibers also make direct excitatory synapses onto motoneurons that innervate the antagonist muscle. Note that the disynaptic reflex pathway does not always have inhibitory effects: under certain conditions, GTO stimulation can result in motoneuron excitation. Besides protecting against too much tension on the muscle and tendon, the tendon reflex may help spread muscle load throughout the muscle fibers, thereby preventing damage to isolated fibers.

The other four nuclei (the external cuneate nucleus, the lateral reticular nucleus, the pontine nucleus, and the thalamic reticular nucleus) project mossy fibers to innervate granule neurons. Meanwhile, cells in the ventricular zone evolve into GABAergic Purkinje cells (another type of cerebellar neuron) and deep cerebellar nuclei.

Alpha motor neurons target extrafusal muscle fibers. The motor nerves associated with these neurons innervate extrafusal skeletal muscle fibers and are responsible for muscle contraction. These nerve fibers have the largest diameter of the motor neurons and require the highest conduction velocity of the three types.

The greater petrosal nerve (or greater superficial petrosal nerve) is a nerve in the skull that branches from the facial nerve; it forms part of a chain of nerves that innervate the lacrimal gland. The preganglionic parasympathetic axons of this nerve synapse in the pterygopalatine ganglion.

Plan of sacral and coccygeal plexuses. Ventral rami of L4-S3 with parts of L4 and S4 spinal nerves form the Sacral plexus. It is located on the posterior wall of pelvic cavity (pelvis minor). Nervi of the plexus innervate the perineal region, buttocks and the lower limb.

The postganglionic axons of the SCG innervate the internal carotid artery and form the internal carotid plexus. The internal carotid plexus carries the postganglionic axons of the SCG to the eye, lacrimal gland, mucous membranes of the mouth, nose, and pharynx, and numerous blood-vessels in the head.

Instead of synapsing, they continue through splanchnic nerves until they reach a prevertebral ganglia (located proximally to their target organ). Once inside the prevertebral ganglia, the individual neurons comprising the nerve synapse with their postganglionic neuron. The postganglionic nerve then proceed to innervate their targets (pelvic visceral organs).

Esophageal and anal rings of A. caninum are the source of nerve fibres that extend throughout the body to innervate sensory organs, including amphids and phasmids. Eggs are laid by the females, typically when at the eight-cell stage. Eggs are 38–43 μm in width, with thin walls.

Alveolar tuft cells are flatter in comparison with intestinal and gall bladder tuft cells have a cuboidal shape. Differences in tuft cells can reflect their organ ‘s specific functions. Tuft cells express chemosensory proteins, like TRPM5 and α-gustducin. These proteins indicate that neighbouring neurons can innervate tuft cells.

The medial giants innervate the entire ventral nerve chord. Their cell bodies and dendrites begin in the brain and collect sensory information presented by visual and tactile stimuli. These fibers terminate in the last abdominal segment. The response is triggered by abrupt tactile stimuli to the head or alarming visual stimuli.

The entorhinal cortex (EC) is composed of six layers. Superficial layer I consists largely of afferent fibers onto the apical dendrites of the cells in layers II-VI. Caudal levels project strongly to rostral levels. Within each EC area, deeper layers innervate superficial layers, with superficial layers innervating adjacent superficial layers.

There is an organization in which dopaminergic neurons of the fringes (the lowest) go to the sensorimotor striatum and the highest to the associative striatum. Dopaminergic axons also innervate other elements of the basal ganglia system, including the lateral and medial pallidum, substantia nigra pars reticulata, and the subthalamic nucleus.

O'Sullivan, S.B & Schmitz, T.J. (2007). Physical Rehabilitation. Philadelphia, PA: Davis. . Problems with these muscles may be due to mechanical problems, disorders of the neuromuscular junction, disorders of the cranial nerves (III, IV, and VI) that innervate the muscles, and occasionally disorders involving the supranuclear oculomotor pathways or ingestion of toxins.

Philadelphia: Elsevier, 2012. 1260-264. Print. Sympathetic postganglionic neurons typically secrete norepinephrine and are named sympathetic adrenergic neurons; however, the sympathetic postganglionic neurons that innervate sweat glands secrete acetylcholine and hence are termed sympathetic cholinergic neurons. Sweat glands, piloerector muscles, and some blood vessels are innervated by sympathetic cholinergic neurons.

Teres major is supplied primarily by the lower subscapular nerve and additionally by the thoracodorsal nerve (middle subscapular nerve). These are distal to the upper subscapular nerve. These three nerves branch off the posterior cord of the brachial plexus. The nerves that innervate teres major consist of fibers from spinal nerves C5-C8.

A branch of the Group III afferent synapse an excitatory interneuron, which extends its axon across the midline into the contralateral spinal cord. At that location, the interneuron excites the alpha motor neurons that innervate the extensor muscles of the opposite leg. This allows for balance and body posture to be maintained.

Anteriorly, the nerve gives off the mental nerve at about the level of the mandibular 2nd premolars, which exits the mandible via the mental foramen and supplies sensory branches to the chin and lower lip. The inferior alveolar nerve continues anteriorly as the mandibular incisive nerve to innervate the mandibular canines and incisors.

Upon emerging from the stylomastoid foramen, the facial nerve gives rise to the posterior auricular branch. The facial nerve then passes through the parotid gland, which it does not innervate, to form the parotid plexus, which splits into five branches (temporal, zygomatic, buccal, marginal mandibular, and cervical) innervating the muscles of facial expression.

These motor neurons indirectly innervate cardiac muscle and smooth muscles of the viscera ( the muscles of the arteries): they synapse onto neurons located in ganglia of the autonomic nervous system (sympathetic and parasympathetic), located in the peripheral nervous system (PNS), which themselves directly innervate visceral muscles (and also some gland cells). In consequence, the motor command of skeletal and branchial muscles is monosynaptic involving only one motor neuron, either somatic or branchial, which synapses onto the muscle. Comparatively, the command of visceral muscles is disynaptic involving two neurons: the general visceral motor neuron, located in the CNS, synapses onto a ganglionic neuron, located in the PNS, which synapses onto the muscle. All vertebrate motor neurons are cholinergic, that is, they release the neurotransmitter acetylcholine.

Beyond the papillae, taste receptors are also in the palate and early parts of the digestive system like the larynx and upper esophagus. There are three cranial nerves that innervate the tongue; the vagus nerve, glossopharyngeal nerve, and the facial nerve. The glossopharyngeal nerve and the chorda tympani branch of the facial nerve innervate the TAS1R and TAS2R taste receptors. Next to the taste receptors in on the tongue, the gut epithelium is also equipped with a subtle chemosensory system that communicates the sensory information to several effector systems involved in the regulation of appetite, immune responses, and gastrointestinal motility In 2010, researchers found bitter receptors in lung tissue, which cause airways to relax when a bitter substance is encountered.

Alpha motor neurons (α-MNs) innervating the head and neck are found in the brainstem; the remaining α-MNs innervate the rest of the body and are found in the spinal cord. There are more α-MNs in the spinal cord than in the brainstem, as the number of α-MNs is directly proportional to the amount of fine motor control in that muscle. For example, the muscles of a single finger have more α-MNs per fibre, and more α-MNs in total, than the muscles of the quadriceps, which allows for finer control of the force a finger applies. In general, α-MNs on one side of the brainstem or spinal cord innervate muscles on that same side of the body.

Prodrome precedes development of lesions. Prodromal symptoms include tingling (paresthesia), itching, and pain where lumbosacral nerves innervate the skin. Prodrome may occur as long as several days or as short as a few hours before lesions develop. Beginning antiviral treatment when prodrome is experienced can reduce the appearance and duration of lesions in some individuals.

Gamma efferents from small multipolar cells from anterior gray column innervate it. These form a part of neuromuscular spindles. Intrafusal muscle fibers are walled off from the rest of the muscle by an outer connective tissue sheath consisting of flattened fibroblasts and collagen. This sheath has a spindle or "fusiform" shape, hence the name "intrafusal".

Following sensory neurogenesis, differentiation occurs, and two types of nociceptors are formed. They are classified as either peptidergic or nonpeptidergic nociceptors, each of which express a distinct repertoire of ion channels and receptors. Their specializations allow the receptors to innervate different central and peripheral targets. This differentiation occurs in both perinatal and postnatal periods.

Cellular Basis of Behavior, an introduction to behavioral neurobiology. W. H. Freeman and Company. Both central ganglia and peripheral neurons are often involved in the neural control of behavior in molluscs. In molluscs such as Aplysia californica the peripheral motor neurons are more extensive, as opposed to vertebrates, and innervate somatic (locomotor and appendageal) muscles.

As development of the olfactory pathway progresses, more axons innervate the olfactory bulb, which develops from the rostral-most region of telencephalon. The organization and subsequent processing of odorant information is possible due to the convergence of olfactory sensory neuron axons expressing the same odorant receptors onto the same glomerulus at the olfactory bulb.

Central damage is damage to the trochlear nucleus. It affects the contralateral eye. The nuclei of other cranial nerves generally affect ipsilateral structures (for example, the optic nerves - cranial nerves II - innervate both eyes). The trochlear nucleus and its axons within the brainstem can be damaged by infarctions, hemorrhage, arteriovenous malformations, tumors and demyelination.

Met-enkephalin is found mainly in the adrenal medulla and throughout the central nervous system (CNS), including in the striatum, cerebral cortex, olfactory tubercle, hippocampus, septum, thalamus, and periaqueductal gray, as well as the dorsal horn of the spinal cord. It is also present in the periphery, notably in some primary afferent fibers that innervate the pelvic viscera.

The solar plexus is the largest autonomic plexus and provides innervation to multiple abdominal and pelvic organs. The superior mesenteric plexus includes the superior mesenteric ganglia and is located around the superior mesenteric artery. The inferior mesenteric plexus includes the inferior mesenteric ganglia and is located around the inferior mesenteric artery. Together, these plexuses innervate the intestines.

It includes spinal cord segments from about C4 to T1. The vertebral levels of the enlargement are roughly the same (C4 to T1). Lumbosacral enlargement - corresponds to the lumbosacral plexus nerves, which innervate the lower limb. It comprises the spinal cord segments from L2 to S3 and is found about the vertebral levels of T9 to T12.

The refractory period of cardiac muscle is distinct from that of skeletal muscle. Nerves that innervate skeletal muscle have an extremely short refractory period after being subjected to an action potential (of the order of 1 ms). This can lead to sustained or tetanic contraction. In the heart, contractions must be spaced to maintain a rhythm.

Swellings called varicosities belonging to an autonomic neuron innervate the smooth muscle cells. Smooth muscles can be divided into two subgroups: single-unit (unitary) and multi-unit. Single-unit smooth muscle cells can be found in the gut and blood vessels. Because these cells are linked together by gap junctions, they are able to contract as a syncytium.

The neurons in the inferior ganglion of the vagus nerve innervate the taste buds on the epiglottis, the chemoreceptors of the aortic bodies and baroreceptors in the aortic arch. Most importantly, the majority of neurons in the inferior ganglion provide sensory innervation to the heart, respiratory and gastrointestinal tracts and other abdominal organs as the urinary bladder.

The anterior grey column, also known as the anterior horn of spinal cord, comprises three different types of neurons: large alpha motor neurons, medium gamma motor neurons, and small neurons thought to be interneurons. These neurons differ in both their morphology and in their patterns of connectivity. They are organized in the same manner as the muscles they innervate.

Alpha motor neurons innervate extrafusal muscle fibers that generate force at neuromuscular junctions at the start of muscle contraction. They have large cell bodies and receive proprioceptive input. They have been shown to reduce in population, but not in size with age. Damage to these cell bodies can lead to severe muscle weakness and loss of reflexes.

Most motor pathways originate in the motor cortex of the brain. Signals run down the brainstem and spinal cord ipsilaterally, on the same side, and exit the spinal cord at the ventral horn of the spinal cord on either side. Motor nerves communicate with the muscle cells they innervate through motor neurons once they exit the spinal cord.

An obsolete treatment is vagotomy ("highly selective vagotomy"), the surgical removal of vagus nerve branches that innervate the stomach lining. This treatment has been largely replaced by medication. Vagotomy by itself tended to worsen contraction of the pyloric sphincter of the stomach, and delayed stomach emptying. Historically, vagotomy was combined with pyloroplasty or gastroenterostomy to counter this problem.

It is innervated by the Ulnar nerve in 50% of people and by both the median and ulnar nerves in 15%. The adductor pollicis is typically innervated by the ulnar nerve. There are normal variations. In a Cannieu-Riche anastomosis, fibers from the deep palmar branch of the ulnar nerve innervate the opponens pollicis and/or abductor pollicis brevis.

The posterior distribution includes the suboccipital nerve (C1), the greater occipital nerve (C2) and the third occipital nerve (C3). The anterior distribution includes the cervical plexus (C1-C4) and brachial plexus (C5-T1). The cervical nerves innervate the sternohyoid, sternothyroid and omohyoid muscles. A loop of nerves called ansa cervicalis is part of the cervical plexus.

The first branch of the facial nerve, the greater petrosal nerve, arises here from the geniculate ganglion. The greater petrosal nerve runs through the pterygoid canal and synapses at the pterygopalatine ganglion. Postsynaptic fibers of the greater petrosal nerve innervate the lacrimal gland. In the tympanic segment, the facial nerve runs through the tympanic cavity, medial to the incus.

There is a strong circadian rhythm of sleep in mammals. The “master clock” for circadian rhythms in mammals is the suprachiasmatic nucleus (SCN). The SCN has little if any projection directly to the VLPO neurons. Instead, they project strongly to the adjacent subparaventricular zone, which in turn contains inhibitory GABAergic neurons that innervate the dorsomedial nucleus of the hypothalamus.

Both the NET and the dopamine transporter (DAT) can transport norepinephrine and dopamine. The reuptake of norepinephrine and dopamine is essential in regulating the concentration of monoamine neurotransmitters in the synaptic cleft. The transporter also helps maintain homeostatic balances of the presynaptic neuron. Norepinephrine structure Norepinephrine (NE) is released from noradrenergic neurons that innervate both the CNS and PNS.

The lateral pectoral nerve (also known as the lateral anterior thoracic nerve) arises from the lateral cord of the brachial plexus, and through it from the fifth, sixth, and seventh cervical nerves. It passes across the axillary artery and vein, pierces the clavipectoral (coracoclavicular) fascia, and enters the deep surface of the pectoralis major to innervate it.

The motor unit: a single motor neuron and the muscle fibers that it innervates. A motor pool consists of all of the motor neurons that innervate a single muscle. Distinct skeletal muscles are controlled by groups of individual motor units. Such motor units are made up of a single motor neuron and the muscle fibers that it innervates.

Once the compression has relieved, regeneration of axons from the lesion site begins. This time though, only 50% of the set of axons that innervate the orbicularis oris successfully reinnervate the original site. The other half aberrantly branched off and innervated the orbicularis oculi(eye muscle). Thus, when the patient purses their lips, the ipsilateral eye will squint.

In more complex organisms an example of chemotropic movement includes the growth of individual neuronal cell axons in response to extracellular signals. Secreted protein can either repel or attract specific neurons. Some signal proteins such as netrins, semaphorins, neurotrophins and fibroblast growth factors have been identified in aiding neuronal growth. These signals guide the developing axon to innervate the correct target tissue.

The largest nerve of the human body, the sciatic nerve is the main branch, that give rami to the motor innervation of the muscles of the foot, the leg and the thigh. Common peroneal nerve and its branches innervate some part of the skin of the foot, the peroneal muscles of the leg and the dorsal muscles of the foot.

Electromyography (EMG) is a tool used to measure the electrical outputs produced by skeletal muscles upon activation. Motor nerves innervate skeletal muscles and cause contraction upon command from the central nervous system. This contraction is measured by EMG and is typically measured on the scale of millivolts (mV). Another form of EMG data that is analyzed is integrated EMG (iEMG) data.

The parvocellular reticular nucleus is part of the brain located dorsolateral to the caudal pontine reticular nucleus. The dorsal portion of the reticular nucleus has been shown to innervate the mesencephalic trigeminal nucleus and its surrounding area. Also, it projects to the facial nucleus, hypoglossal nucleus and parabrachial area along with parts of the caudal parvocellular reticular formation.Ter Horst, GJ et al.

The gigantocellular reticular nucleus (Gi) is a subregion of the medullary reticular formation. As the name indicates, it consists mainly of so-called giant neuronal cells. This nucleus has been known to innervate the caudal hypoglossal nucleus, and responds to glutamatergic stimuli. The gigantocellular nucleus excites the hypoglossal nucleus, and can play a role in the actions of the said nerve.

After the fusion of the main nerve trunks of the nonclamp side, some prominent nerves arise to innervate the lappet. The innervation is different from that of Gastrocotyle trachuri. This is probably due to the attitude of clamps formation of P. trachuri, that occur in a posteroanterior direction, thus, the “prehaptoral” ganglion moves more anteriorly, close to the anteriormost clamps.

Immunostaining allows the classification of SCG neurons as either positive or negative for neuropeptide Y (NPY), which is found in a subgroup of high-threshold neurons. Low threshold, NPY-negative neurons are secretomotor neurons, innervating salivary glands. High threshold, NPY-negative neurons are vasomotor neurons, innervating blood vessels. High threshold, NPY-positive neurons are vasoconstrictor neurons, which innervate the iris and pineal gland.

The SCG receives input from the ciliospinal center. The ciliospinal center is located between the C8 and T1 regions of the spinal cord within the intermediolateral column. The preganglionic fibers that innervate the SCG are the thoracic spinal nerves, which extend from the T1-T8 region of the ciliospinal center. These nerves enter the SCG through the cervical sympathetic nerve.

In the late 19th century, John Langley discovered that the superior cervical ganglion is topographically organized. When certain areas of the superior cervical ganglion were stimulated, a reflex occurred in specified regions of the head. His findings showed that preganglionic neurons innervate specific postganglionic neurons. In his further studies of the superior cervical ganglion, Langley discovered that the superior cervical ganglion is regenerative.

In humans, the spinal cord comprises a major part of the central nervous system (CNS). Along with the brain, it develops from the dorsal nerve cord in the embryonic stage. The spinal cord consists of such segmental enlargements called ganglia. These ganglia form the basis for the peripheral nervous system’s (PNS) sensory and motor neurons that innervate various parts of the body.

Similar to the paravertebral ganglia, the prevertebral ganglia are the nodules where preganglionic neurons synapse with their postganglionic counterparts. The nerves that synapse in the prevertebral ganglia innervate the pelvic viscera. Some of the targets present in the pelvic viscera include the enteric nervous system, as well as the renal system, bladder, and any other organs present in the abdomen.

As with most British surgeons of his day (1805–1878), he intensely studied anatomy. The knee joint is supplied by branches from femoral nerve, sciatic nerve, and obturator nerve because all the three nerves are supplying the muscles moving the joint. These nerves not only innervate the muscles, but also the fibrous capsule, ligaments, and synovial membrane of the knee joint.

C fibers have slow conduction velocities of less than 1.3 m/s because they do not have a myelin sheath at all. C fibers account for 60-70% of primary afferent neurons that innervate the skin. C fibers are activated by both mechanical and thermal stimuli, and also respond to algesic chemicals, such as capsaicin. Some C fibers respond only to mechanical stimuli.

The fibers of the chorda tympani travel with the lingual nerve to the submandibular ganglion. Here, the preganglionic fibers of the chorda tympani synapse with postganglionic fibers which go on to innervate the submandibular and sublingual salivary glands. Special sensory (taste) fibers also extend from the chorda tympani to the anterior 2/3 of the tongue via the lingual nerve.

GLP1R is also expressed in the brain where it is involved in the control of appetite. Furthermore, mice that over express GLP1R display improved memory and learning. Stretch responsive vagal neurons in the stomach and intestines also express GLP1R. GLP1R neurons particularly and densely innervate stomach muscle and can communicate with additional organ systems changing breathing and heart rate due to activation.

The ansa cervicalis (or ansa hypoglossi in older literature) is a loop of nerves that are part of the cervical plexus. It lies superficial to the internal jugular vein in the carotid triangle. Its name means "handle of the neck" in Latin. Branches from the ansa cervicalis innervate most of the infrahyoid muscles, including the sternothyroid muscle, sternohyoid muscle, and the omohyoid muscle.

The meningeal branch of the vagus nerve is one of the first branches of the vagus nerve at the level of the superior ganglion. The neuron cell bodies reside within the superior ganglion and innervate the dura mater in the posterior cranial fossa of the base of the skull. The meningeal branch passes back into the skull through the jugular foramen.

They contain Dogiel cells. The nerve bundles of the submucous plexus are finer than those of the myenteric plexus. Its function is to innervate cells in the epithelial layer and the smooth muscle of the muscularis mucosae. 14% of submucosal plexus neurons are sensory neurons - Dogiel type II, also known as enteric primary afferent neurons or intrinsic primary afferent neurons.

Parasympathetic fibers travel with cranial nerve III, the oculomotor nerve, to innervate the circular layer of muscle of the eye (sphincter pupillae). Damage to this nerve typically manifests itself as mydriasis, because the sympathetic supply to the pupil, which causes mydriasis, remains unaffected, and therefore unopposed. Multiple central nervous system disorders e.g. epilepsy, stroke, and impending brain herniation are known to lead to temporal mydriasis as well.

Pain in the external auditory canal (otalgia) can in rare cases be due to vagal neuralgia because of vascular compression of the vagus nerve (often by the posterior inferior cerebellar artery). The affected neurons are found in the superior ganglion and innervate the ear via the auricular branch of the vagus. The condition is treated by microvascular decrompression of the vagus nerve where it exits the brainstem.

There are two parotid glands in the human body. Each parotid gland is located high in the neck just below the ears. A salivary duct by which saliva is secreted (produced and released), runs through the inside of each cheek from each gland. Furthermore, the extratemporal (outside temporal bone) facial nerve and its subsidiaries run through the parotid gland and innervate (supply nerves to) the face.

The carotid canal allows the internal carotid artery to pass into the cranium, as well as the carotid plexus traveling on the artery. The carotid plexus contains sympathetics to the head from the superior cervical ganglion They have several motor functions: raise the eyelid (superior tarsal muscle), dilate pupil (pupillary dilator muscle), innervate sweat glands of face and scalp and constricts blood vessels in the head.

A touch user interface (TUI) is a computer-pointing technology based upon the sense of touch (haptics). Whereas a graphical user interface (GUI) relies upon the sense of sight, a TUI enables not only the sense of touch to innervate and activate computer-based functions, it also allows the user, particularly those with visual impairments, an added level of interaction based upon tactile or Braille input.

As these processes elongate, two lateral FMRFamide-expressing cells are apparent on either side of the body wall. Some studies have suggested that FMRFamide these structures may innervate muscles that originate in trochopore larvae and expand during development. This neuromodulator helps to regulate cardiac activity. Several FMRFamid related peptides are known, regulating various cellular functions and possessing pharmacological actions, such as anti-opiate effects.

In the cytosol, noradrenaline is converted to epinephrine by the enzyme phenylethanolamine N-methyltransferase (PNMT) and stored in granules. Glucocorticoids produced in the adrenal cortex stimulate the synthesis of catecholamines by increasing the levels of tyrosine hydroxylase and PNMT. Catecholamine release is stimulated by the activation of the sympathetic nervous system. Splanchnic nerves of the sympathetic nervous system innervate the medulla of the adrenal gland.

The opponens pollicis and abductor pollicis brevis are normally innervated by the median nerve. The flexor pollicis brevis has two heads a superficial and a deep. The flexor pollicis brevis (FPB) is typically an ulnar-innervated muscle. Due to a common interconnection between the median and ulnar nerves in the hand (Riche- Cannieu interconnection), the Median nerve may innervate the FPB in 35% of people.

Cardiopulmonary nerves are splanchnic nerves that are postsynaptic and sympathetic. They originate in cervical and upper thoracic ganglia and innervate the thoracic cavity. All major sympathetic cardiopulmonary nerves arise from the stellate ganglia and the caudal halves of the cervical sympathetic trunks below the level of the cricoid cartilage. Parasympathetic cardiopulmonary nerves arise from the recurrent laryngeal nerves and the thoracic vagus immediately distal to them.

The axillary nerve or the circumflex nerve is a nerve of the human body, that originates from the brachial plexus (upper trunk, posterior division, posterior cord) at the level of the axilla (armpit) and carries nerve fibers from C5 and C6. The axillary nerve travels through the quadrangular space with the posterior circumflex humeral artery and vein to innervate the deltoid and teres minor.

The oculomotor nerve passes through the lateral wall of the cavernous sinus and enters the orbit through the superior orbital fissure. It divides into branches that innervate the levator palpebrae superioris and four of the six extraocular muscles. Parasympathetic fibers initially run in the inferior division of the oculomotor nerve. They exit as one or two short “motor roots” that synapse in the ciliary ganglion.

Each Edinger-Westphal nucleus gives rise to preganglionic parasympathetic fibers which exit with CN III and synapse with postganglionic parasympathetic neurons in the ciliary ganglion. Postganglionic nerve fibers leave the ciliary ganglion to innervate the ciliary sphincter. Each afferent limb has two efferent limbs, one ipsilateral and one contralateral. The ipsilateral efferent limb transmits nerve signals for direct light reflex of the ipsilateral pupil.

Another consequence is the depression of deep tendon reflexes, causing hyporeflexia. Muscle weakness and atrophy are inevitable consequences of α-MN lesions as well. Because muscle size and strength are related to the extent of their use, denervated muscles are prone to atrophy. A secondary cause of muscle atrophy is that denervated muscles are no longer supplied with trophic factors from the α-MNs that innervate them.

Conversely, FF type neurons, which innervate the largest muscle fibers, require a greater input potential to reach the threshold. Therefore, the axonal diameter of the three subclasses of alpha motor neurons clearly determines the patterns of the recruitment of motor units predicted by the size principle. The specific regulatory mechanisms that determine the size of these three alpha-motor neuron subclasses are not well known.

The aberrant nerve regeneration hypothesis is the most widely accepted mechanism for synkinesis. The hypothesis states that, after trauma, axons project from the facial nucleus to incorrect peripheral muscle groups. These aberrant branches can simultaneously innervate different subdivisions of the facial nerve. For example: compression to the facial nerve causes a lesion and the set of axons that innervates the orbicularis oris (mouth muscle) degenerate.

At very high doses it dampens neuronal activity. Nicotine induces both behavioral stimulation and anxiety in animals. Research into nicotine's most predominant metabolite, cotinine, suggests that some of nicotine's psychoactive effects are mediated by cotinine. Nicotine activates nicotinic receptors (particularly α4β2 nicotinic receptors) on neurons that innervate the ventral tegmental area and within the mesolimbic pathway where it appears to cause the release of dopamine.

The nervous system of sea urchins has a relatively simple layout. With no true brain, the neural center is a large nerve ring encircling the mouth just inside the lantern. From the nerve ring, five nerves radiate underneath the radial canals of the water vascular system, and branch into numerous finer nerves to innervate the tube feet, spines, and pedicellariae. Sea urchins are sensitive to touch, light, and chemicals.

Hippocampal basket cells target somata and proximal dendrites of pyramidal neurons. Similar to their counterparts in the cortex, hippocampal basket cells are also parvalbumin- expressing and fast-spiking. In the CA3 region of the hippocampus, basket cells can often form recurrent inhibition loops with pyramidal cells. Projections from a pyramidal cell will innervate the basket cell, which in turn has a projection back onto the original pyramidal cells.

Cervical plexus The Cervical plexus is formed by the ventral rami of the upper four cervical nerves and the upper part of fifth cervical ventral ramus. The network of rami is located deep to the sternocleidomastoid within the neck. The cervical plexus innervates muscles of the neck and areas of skin on the head, neck and chest. The deep branches innervate muscles, while the superficial branches supply areas of skin.

The pectoral muscles were chosen targets because they were close to the shoulder, and they were also biologically non-functional due to detachment from the amputated arm. The pectoral muscles were first denervated by cutting the original nerves that innervate them. The proximal ends of the original nerves were ligated to prevent them from reinnervating the pectoral muscle. Then the remnant arm nerves (brachial plexus) were transferred into the pectoral muscles.

The lumbar splanchnic nerves are splanchnic nerves that arise from the lumbar part of the sympathetic trunk and travel to an adjacent plexus near the aorta. They originate from L1 and L2. These nerves contain preganglionic sympathetic and general visceral afferent fibers. The site of synapse is found in the inferior mesenteric ganglion and the postsynaptic fibers innervate the smooth muscle and glands of the pelvic viscera and hindgut.

The postganglionic axons of the SCG innervate blood vessels in the skin and cause the vessels to constrict. Constriction of the blood vessels causes a decrease in blood flow to the skin leading to paling of the skin and retention of body heat. This plays into the fight-or-flight response, decreasing blood flow to facial skin and redirecting the blood to more important areas like the blood vessels of muscles.

The lumbar region L1 and L2 consist of neurons that innervate the adrenal gland, ureter, bladder, the lower extremities. The upper two lumbar ganglia (L1 and L2) of the sympathetic chain also give rise to the lumbar splanchnic nerves. Splanchnic nerves are paired visceral nerves carrying preganglionic sympathetic and general visceral afferent fibers. The lumbar splanchnic nerves travel through the lumbar sympathetic ganglion but do not synapse there.

Neuronal tiling is a phenomenon in which multiple arbors of neurons innervate the same surface or tissue in a nonredundant and tiled pattern that maximizes coverage of the surface while minimizing overlap between neighboring arbors.Grueber, W. B. & Sagasti, A. Self-avoidance and tiling: Mechanisms of dendrite and axon spacing. Cold Spring Harb. Perspect. Biol. 2, a001750 (2010) Hence, dendrites of the same neuron spread out by avoiding one another (self- avoidance).

Scheme showing sympathetic and parasympathetic innervation of the pupil and sites of lesion in a Horner's syndrome. Pathways in the Ciliary Ganglion. Green = parasympathetic; Red = sympathetic; Blue = sensoryThe ciliary ganglion contains postganglionic parasympathetic neurons that supply the ciliary muscle and the pupillary sphincter muscle. Because of the much larger size of the ciliary muscle, 95% of the in neurons in the ciliary ganglion innervate it compared to the pupillary sphincter.

This connection carries motor axons which innervate some of the usually ulnar nerve innervated intrinsic muscles. This inconstant pattern of connection can serve as explanation for a difficult or challenging differential diagnosis. In one study, the MGA was found in 22.9% of cadaver specimens, while another found the incidence at ~11% . This relatively high incidence demonstrates the necessity for healthcare specialists to factor the MGA into their diagnoses.

Heartbeats originate in nervous tissue; innervated muscle cells cause the heart to contract when stimulated by nerve impulses. The cardiac ganglion, which consists of nine neurons, attaches to the dorsal wall of the heart. The anterior neurons innervate the heart, whereas the other posterior neurons make synaptic contact with those anterior neurons. The posterior neuron acts as the pacemaker but also functions as the cellular oscillator and the central pattern generator.

Specific terms are used to describe nerves and their actions. A nerve that supplies information to the brain from an area of the body, or controls an action of the body is said to "innervate" that section of the body or organ. Other terms relate to whether the nerve affects the same side ("ipsilateral") or opposite side ("contralateral") of the body, to the part of the brain that supplies it.

The 10th intercostal nerve terminates at the navel. The twelfth (subcostal) thoracic is distributed to the abdominal wall and groin. Unlike the nerves from the autonomic nervous system that innervate the visceral pleura of the thoracic cavity, the intercostal nerves arise from the somatic nervous system. This enables them to control the contraction of muscles, as well as provide specific sensory information regarding the skin and parietal pleura.

Olfactory sensory neurons (OSNs) express odorant receptors. The axons of OSNs expressing the same odorant receptors converge onto the same glomerulus at the olfactory bulb, allowing for the organization of olfactory information.Olfaction results from the proper development and interaction of the two components of the primary olfactory pathway: the olfactory epithelium and the olfactory bulb. The olfactory epithelium contains olfactory sensory neurons, whose axons innervate the olfactory bulb.

It is controlled by parasympathetic fibers of the muscarinic acetylcholine receptor (M3) that originate from the Edinger–Westphal nucleus, travel along the oculomotor nerve (CN III), synapse in the ciliary ganglion, and then enter the eye via the short ciliary nerves.. The short ciliary nerves then run forward and pierce the sclera at the back of the eye, traveling between the sclera and the choroid to innervate the iris sphincter muscle.

The corticospinal tract is one of the major descending pathways from the brain to the α-MNs of the spinal cord. In the spinal cord, α-MNs are located within the gray matter that forms the ventral horn. These α-MNs provide the motor component of the spinal nerves that innervate muscles of the body. Alpha motor neurons are located in lamina IX according to the Rexed lamina system.

Type I neurons innervate inner hair cells. There is significantly greater convergence of this type of neuron towards the basal end in comparison with the apical end. A radial fiber bundle acts as an intermediary between Type I neurons and inner hair cells. The ratio of innervation that is seen between Type I neurons and inner hair cells is 1:1 which results in high signal transmission fidelity and resolution.

Instead, individual gustatory nuclei processing information is influenced by separate taste bud populations. Some examples of gustatory cranial nerves, that innervate the taste buds and are connected to this nucleus include the chorda tympani and lingual branch of the glossopharyngeal nerves. Tastants are the chemical molecules that provide the stimulus for taste perception. The concentration of this taste stimulus is what dictates the intensity of the taste sensation that is perceived.

There are normal variations in the muscles nerve innervation. In a Cannieu-Riche anastomosis, fibers from the deep palmar branch of the ulnar nerve innervate the opponens pollicis and/or abductor pollicis brevis. Regardless of their final innervation, the nerves that reach the thenar muscles arise from the C8 and T1 roots, pass through the lower trunk of the plexus, and then through the medial cord of the plexus.

H&E; stained fibers of the vagus nerve (bottom right) innervate the sinoatrial node tissue (middle left) Parasympathetic innervation of the heart is partially controlled by the vagus nerve and is shared by the thoracic ganglia. Vagal and spinal ganglionic nerves mediate the lowering of the heart rate. The right vagus branch innervates the sinoatrial node. In healthy people, parasympathetic tone from these sources are well-matched to sympathetic tone.

The pituitary gland consists of three parts: the pars nervosa, the pars intermedia, and the pars distalis. The most critical structure to PPID, the pars intermedia, is regulated by the hypothalamus. The neurons of the hypothalamus innervate cells known as melanotropes within the pars intermedia, releasing dopamine which then binds to dopamine receptors on the melanotropes. Activation of these dopamine receptors leads to the inhibition of proopiomelanocortin (POMC) production from these cells.

The autogenic inhibition reflex is a spinal reflex phenomenon that involves the Golgi tendon organ. When tension is applied to a muscle, group Ib fibers that innervate the Golgi tendon organ are activated. These afferent fibers project onto the spinal cord and synapse with the spinal interneurons called Ib inhibitory interneurons. This spinal interneuron makes an inhibitory synapse onto the alpha motor neuron that innervates the same muscle that caused the Ib afferent to fire.

Lamina I is also known as the marginal nucleus of spinal cord. The majority of posterior column projection neurons are located in lamina I, however most neurons in this layer are interneurons. The main areas these neurons innervate are the caudal ventrolateral medulla (CVLM), the nucleus of the solitary tract (NTS), the lateral parabrachial area (LPb), the periaqueductal grey matter (PAG), and certain regions in the thalamus. The CVLM receives nociceptive and cardiovascular responses.

Neurons of the auditory or vestibulocochlear nerve (the eighth cranial nerve) innervate cochlear and vestibular hair cells. The neurotransmitter released by hair cells that stimulates the terminal neurites of peripheral axons of the afferent (towards the brain) neurons is thought to be glutamate. At the presynaptic juncture, there is a distinct presynaptic dense body or ribbon. This dense body is surrounded by synaptic vesicles and is thought to aid in the fast release of neurotransmitter.

The oculomotor nerve is the third cranial nerve (CN III). It enters the orbit via the superior orbital fissure and innervates extrinsic eye muscles that enable most movements of the eye and that raise the eyelid. The nerve also contains fibers that innervate the intrinsic eye muscles that enable pupillary constriction and accommodation (ability to focus on near objects as in reading). The oculomotor nerve is derived from the basal plate of the embryonic midbrain.

The trochlear nerve provides motor supply to the superior oblique muscle of the eye, The trochlear nerve carries axons of type GSE, general somatic efferent, which innervate skeletal muscle of the superior oblique muscle. The superior oblique muscle ends in a tendon that passes through a fibrous loop, the trochlea, located anteriorly on the medial aspect of the orbit. Trochlea means “pulley” in Latin; the fourth nerve is named after this structure.

PreproGRP begins with signal peptidase cleavage to generate the proGRP, which is then processed (by proteolytic cleavages), to form smaller GRP peptides. These smaller peptides are released by the post- ganglionic fibers of the vagus nerve, which innervate the G cells of the stomach and stimulate them to release gastrin. GRP regulates numerous functions of the gastrointestinal and central nervous systems, including release of gastrointestinal hormones, smooth muscle cell contraction, and epithelial cell proliferation.

The Times. Retrieved on 2009-12-03. Jon Caramanica of The New York Times questioned the lyrics' substance and called Graffiti "a curiously faceless album that largely thumbs its nose at close reading". However, Steve Jones of USA Today gave the album two-and-a-half out of four stars and commented that Brown "succeeds in expanding his sonic horizons with rock and Euro-dance influenced rhythms that are sure to ignite dance floors and innervate his electrifying performances".

Peripheral expression of cannabinoid receptors led researchers to investigate the role of cannabinoids in the autonomic nervous system. Research found that the CB1 receptor is expressed presynaptically by motor neurons that innervate visceral organs. Cannabinoid-mediated inhibition of electric potentials results in a reduction in noradrenaline release from sympathetic nervous system nerves. Other studies have found similar effects in endocannabinoid regulation of intestinal motility, including the innervation of smooth muscles associated with the digestive, urinary, and reproductive systems.

Phantom pain refers to dysesthetic feelings in individuals who are paralyzed or who were born without limbs. It is caused by the improper innervation of the missing limbs by the nerves that would normally innervate the limb. Dysesthesia is caused by damage to the nerves themselves, rather than by an innervation of absent tissue. Dysesthesia should not be confused with anesthesia or hypoesthesia, which refer to a loss of sensation, or paresthesia which refers to a distorted sensation.

These preganglionic neurons then enter the SCG and synapse with the postganglionic neurons that leave the rostral end of the SCG and innervate target organs of the head. There are a number of neuron types in the SCG ranging from low threshold to high threshold neurons. The neurons with a low threshold have faster action potential firing rate, while the high threshold neurons have a slow firing rate. Another distinction between SCG neuron types is made via immunostaining.

The postganglionic axons of the Superior cervical ganglion innervate the eye and lacrimal gland and cause vasoconstriction of the iris and sclera, pupillary dilation, widening of the palpebral fissure, and the reduced production of tears. These responses are important during Fight-or-flight response of the ANS. Dilation of the pupils allows for an increased clarity in vision, and inhibition of the lacrimal gland stops tear production allowing for unimpaired vision and redirection of energy elsewhere.

The first five abdominal segments each have their own ganglion, that contains three roots with outward projections. The first has mixed sensory and motor nerves innervating swimmerets while the second has sensory and motor neurons that innervate the extensor muscles, while the third root contains only motor neuron projections that extend into the flexor muscles. The last segment contains the fusion of two ganglia. The ganglia here also receive sensory input from the sensitive hairs on the tail fan.

Each ganglion contains the body of one motor giant neuron (MoG), powerful and large bodied motor neurons whose projections innervate the five fast flexor (FF) muscles found in a segment and interact with them through chemical synapses. The ganglia also contain two sets of giant axons known as the lateral giant neurons and the medial giant neurons. These interneurons play important roles in escape swimming. Their large diameter allows for rapid conduction since there is less current leakage.

This bridge is a shorter distance for axonal growth than the original route. Once the axon has innervated both sites, it continues growing in a retrograde direction (toward the injury site) to innervate other affected NMJs. PSCs have a large role in creating growth scaffolds from one injured NMJ to another. These PSC bridges are seen in vivo following complement-mediated injury in a murine model, showing that this role of PSCs are present in mammalian NMJs.

The projections of this nucleus reach far and wide. For example, they innervate the spinal cord, the brain stem, cerebellum, hypothalamus, the thalamic relay nuclei, the amygdala, the basal telencephalon, and the cortex. The norepinephrine from the LC has an excitatory effect on most of the brain, mediating arousal and priming the brain's neurons to be activated by stimuli. As an important homeostatic control center of the body, the locus coeruleus receives afferents from the hypothalamus.

Other synapses appear as terminals at the ends of axonal branches. A single axon, with all its branches taken together, can innervate multiple parts of the brain and generate thousands of synaptic terminals. A bundle of axons make a nerve tract in the central nervous system, and a fascicle in the peripheral nervous system. In placental mammals the largest white matter tract in the brain is the corpus callosum, formed of some 200 million axons in the human brain.

501-524 This tract results in collateral fibers that innervate the rostral boundary of the medial octavolateralis nucleus, the area in all teleosts where lateral line organs innervate.McCormick. C.A. (1982) "Central projections of lateral line and eight nerves in the bowfin, Amia calva". Journal of Comparative Physiology 197:1-15, cited in Coombs S., Görner P., and Münz H. eds. The Mechanosensory Lateral Line: Neurobiology and Evolution (New York: Springer-Verlag New York Inc., 1989), pp.

Due to the effect on swallowing, secretions of mucus may build up in the airway, causing suffocation. Other signs and symptoms include facial weakness (caused by destruction of the trigeminal nerve and facial nerve, which innervate the cheeks, tear ducts, gums, and muscles of the face, among other structures), double vision, difficulty in chewing, and abnormal respiratory rate, depth, and rhythm (which may lead to respiratory arrest). Pulmonary edema and shock are also possible and may be fatal.

Motor nerve axon terminals innervate skeletal and smooth muscle, as they are heavily involved in muscle control. Motor nerves tend to be rich in Acetylcholine vesicles because the motor nerve, a bundle of motor nerve axons that deliver motor signals and signal for movement and motor control. Calcium vesicles reside in the axon terminals of the motor nerve bundles. The high calcium concentration outside of presynaptic motor nerves increases the size of EPPs (End-Plate potentials).

The salivatory nuclei are the superior salivatory nucleus, and the inferior salivatory nucleus that innervate the salivary glands. They are located in the pontine tegmentum in the brainstem. They both are examples of cranial nerve nuclei. The superior salivatory nucleus innervates the submandibular gland and the sublingual gland and is part of the facial nerve The inferior salivatory nucleus innervates the parotid gland by way of the otic ganglion and forms the parasympathetic component of the glossopharyngeal nerve.

These fibers synapse in the pterygopalatine ganglion, whereupon the postganglionic, postsynaptic, efferent fibers travel to innervate the lacrimal gland and the mucosal glands of the nose, palate, and pharynx. Preganglionic parasympathetic fibers are also distributed partly via the chorda tympani and lingual nerves to the submandibular ganglion, thence by postganglionic (vasodilator) fibers to the submandibular and sublingual salivary glands. The term "lacrimal nucleus" is sometimes used to refer to a portion of the superior salivatory nucleus.

Free nerve endings, many of which act as nociceptors, innervate the bones, ligaments, and muscles of the TMJ. The fibrocartilage that overlays the TMJ condyle is not innervated and is avascular in healthy TMJs. When bone tissue, ligaments, or muscles become inflamed or injured, sensory signals are relayed along small-diameter primary afferent nerve fibers that form the trigeminal nerve. Signals are directed through the trigeminal nerve and modulated by neuronal cell bodies in the trigeminal ganglion.

Schacter D.L., Gilbert D.T., and Wegner D.M. (2011) Psychology second edition. New York, NY: Worth Types of lower motor neurons are alpha motor neurons, beta motor neurons, and gamma motor neurons. A single motor neuron may innervate many muscle fibres and a muscle fibre can undergo many action potentials in the time taken for a single muscle twitch. Innervation takes place at a neuromuscular junction and twitches can become superimposed as a result of summation or a tetanic contraction.

The common fibular nerve (common peroneal nerve; external popliteal nerve; lateral popliteal nerve) is a nerve in the lower leg that provides sensation over the posterolateral part of the leg and the knee joint. It divides at the knee into two terminal branches: the superficial fibular nerve and deep fibular nerve, which innervate the muscles of the lateral and anterior compartments of the leg respectively. When the common fibular nerve is damaged or compressed, foot drop can ensue.

Beta motor neurons (β motor neurons), also called beta motoneurons, are a kind of lower motor neuron, along with alpha motor neurons and gamma motor neurons. Beta motor neurons innervate intrafusal fibers of muscle spindles with collaterals to extrafusal fibers - a type of slow twitch fiber. Also, axons of alpha, beta, and gamma motor neurons become myelinated. Moreover, these efferent neurons originate from the anterior grey column of the spinal cord and travel to skeletal muscles.

One advantage to having plexes is that damage to a single spinal nerve will not completely paralyze a limb. There are four main plexuses formed by the ventral rami: the cervical plexus contains ventral rami from spinal nerves C1-C4. Branches of the cervical plexus, which include the phrenic nerve, innervate muscles of the neck, the diaphragm, and the skin of the neck and upper chest. The brachial plexus contains ventral rami from spinal nerves C5-T1.

Other chordates do not show any trends towards cephalisation. A peripheral nervous system branches out from the nerve cord to innervate the various systems. The front end of the nerve tube is expanded by a thickening of the walls and expansion of the central canal of spinal cord into three primary brain vesicles: The prosencephalon (forebrain), mesencephalon (midbrain) and rhombencephalon (hindbrain), further differentiated in the various vertebrate groups.Hildebrand, M.; Gonslow, G. (2001): Analysis of Vertebrate Structure.

For example, poliomyelitis is caused by a virus that specifically targets and kills motor neurons in the ventral horn of the spinal cord. Amyotropic lateral sclerosis likewise is associated with the selective loss of motor neurons. Paralysis is one of the most pronounced effects of damage to α-MNs. Because α-MNs provide the only innervation to extrafusal muscle fibers, losing α-MNs effectively severs the connection between the brainstem and spinal cord and the muscles they innervate.

Wu X, Ashe J, Bushara KO. Role of olivocerebellar system in timing without awareness. Proc Natl Acad Sci U S A 2011. In the central nervous system, these fibers are able to undergo remarkable regenerative modifications in response to injuries, being able to generate new branches by sprouting to innervate surrounding Purkinje cells if these lose their CF innervation. This kind of injury-induced sprouting has been shown to need the growth associated protein GAP-43.

According to the Chemoaffinity hypothesis, chemical labels are distributed in a graded fashion across the retina and tectum. This allows each retinal ganglion cell to recognize its proper termination site. Experiments with artificially created compound eyes in Xenopus demonstrate that not only the ganglion cells but also their axons carry these specificities. Axons must be able to communicate with each other to ensure that ones with the same positional tags innervate the same area of the superior colliculus.

Three of the twelve cranial nerves send input to the Gustatory nucleus: the facial nerve (VII), the glossopharyngeal nerve (IX), and the vagus nerve (X). Taste cells synapse with primary sensory axons of three cranial nerves; the facial nerve, glossopharyngeal nerve, and the vagus nerve. These cranial nerves innervate the taste buds in the tongue, palate, epiglottis, and esophagus. The primary sensory neurons of these central axons are in the cranial nerve ganglia of each respective cranial nerve.

Positive feedback by estrogens also occurs in the gonadal axis of female mammals and is responsible for the midcycle surge of LH that stimulates ovulation. Although estrogens inhibit kisspeptin (Kp) release from kiss1 neurons in the ARC, estrogens stimulate Kp release from the Kp neurons in the AVPV. As estrogens' levels gradually increase the positive effect predominates, leading to the LH surge. GABA-secreting neurons that innervate GnRH-1 neurons also can stimulate GnRH-1 release.

This consists of motor neuron axons that branch out to the muscles from the ganglia of the central nervous system, parts of the sympathetic nervous system and the sensory neurons of the cuticular sense organs that receive chemical, thermal, mechanical or visual stimuli from the insects environment. The sympathetic nervous system includes nerves and the ganglia that innervate the gut both posteriorly and anteriorly, some endocrine organs, the spiracles of the tracheal system and the reproductive organs.

This may lead to several symptoms such as incomplete eye closure with or without exposure keratitis, oral incompetence, poor articulation, dental caries, drooling, and a low self-esteem. This is because the different branches innervate the frontalis muscle, orbicularis oculi and oris muscles, lip elevators and depressors, and the platysma. The elevators of the upper lip and corner of the mouth are innervated by the zygomatic and buccal branches. When these branches are paralysed, there is an inability to create a symmetric smile.

A mature preganglionic axon can innervate anywhere from 50-200 SCG cells. Postganglionic fibers then leave the SCG via the internal carotid nerve and the external carotid nerve. This pathway of SCG innervation is shown through stimulation of the cervical sympathetic nerve, which invokes action potentials in both the external and internal carotid nerves. These postganglionic fibers shift from multiple axon innervation of their targets to less profound multiple axon innervation or single axon innervation as the SCG neurons mature during postnatal development.

Similarly to ferroptosis, deficiencies in apoptotic processes can result in many health complications, including neurodegeneration. Within the study of neuronal apoptosis, most research has been conducted on the neurons of the superior cervical ganglion. In order for these neurons to survive and innervate their target tissues, they must have nerve growth factor (NGF). Normally, NGF binds to a tyrosine kinase receptor, TrkA, which activates phosphatidylinositol 3-kinase-Akt (PI3K-Akt) and extracellular signal-regulated kinase (Raf-MEK- ERK) signaling pathways.

They ascend into the white matter of the cerebellum, where each axon branches to innervate granule cells in several cerebellar folia. In this case, the pathway is so named for a unique synapse formed by its projections, the mossy fiber rosette. Fine branches of the mossy fiber axons twist through the granule cell layer, and slight enlargements giving a knotted appearance indicate synaptic contacts. These contacts have the appearance of a classic Gray's type 1 synapse, indicating they are glutamatergic and excitatory.

The nerve axons traveling down the tract are the efferent nerve fibers of the upper motor neurons. These axons travel down the tracts in the white matter of the spinal cord until they reach the vertebral level of the muscle that they will innervate. At this point, the axons synapse with lower motor neurons. The majority of axons do not directly synapse with lower motor neurons, but instead synapse with an interneuron that then synapses with a lower motor neuron.

Tetany or tetanic seizure is a medical sign consisting of the involuntary contraction of muscles, which may be caused by disorders that increase the action potential frequency of muscle cells or the nerves that innervate them. Muscle cramps caused by the disease tetanus are not classified as tetany; rather, they are due to a lack of inhibition to the neurons that supply muscles. Tetanic contractions (physiologic tetanus) are a broad range of muscle contraction types, of which tetany is only one.

Adrenergic fibres innervate smooth muscle, cardiac muscle, visceral glands, and various central nervous system structures and sense organs. Their function is enhancing, compared to the inhibiting action of the cholinergic fibres of the parasympathetic system. Peripheral adrenergic neurons integrate signals from other nerves of the central nervous system and peripheral sense organs. An adrenergic nerve impulse is triggered when one nerve fires repeatedly or when several nerves fire simultaneously which can cause an additive effect leading to a greater stimulus.

The olivocochlear bundle (OCB) originates in the superior olivary complex in the brainstem. The vestibulocochlear anastomosis carries the efferent axons into the cochlea, where they innervate the organ of Corti (OC). The OCB contains fibres projecting to both the ipsilateral and contralateral cochleae, prompting an initial division into crossed (COCB) and uncrossed (UCOCB) systems. More recently, however, the division of the OCB is based on the cell bodies’ site of origin in the brainstem relative to the medial superior olive (MSO).

The nervous system derives its name from nerves, which are cylindrical bundles of fibers (the axons of neurons), that emanate from the brain and spinal cord, and branch repeatedly to innervate every part of the body. Nerves are large enough to have been recognized by the ancient Egyptians, Greeks, and Romans, but their internal structure was not understood until it became possible to examine them using a microscope.Finger, pp. 43–50 The author Michael Nikoletseas wrote:Nikoletseas Michael M. (2010) Behavioral and Neural Plasticity.

Once they synapse in the sympathetic ganglion in the sympathetic trunk, they exit the trunk as gray rami to join the spinal nerve and innervate the appropriate structure. Even though the sympathetic trunk extends below L2, there are no more white rami communicantes below L2 because the intermediolateral cell column ends before this. The fibers of the sympathetic trunk above and below T1-L2 originate from white rami communicantes within T1-L2. Above and below T1-L2 there are only gray rami.

The suboesophageal ganglion (acronym: SOG; synonym: subesophageal ganglion) of arthropods and in particular insects is part of the arthropod central nervous system (CNS). As indicated by its name, it is located below the oesophagus, inside the head. As part of the ventral nerve cord, it is connected (via pairs of connections) to the brain (or supraoesophageal ganglion) and to the first thoracic ganglion (or protothoracic ganglion). Its nerves innervate the sensory organs and muscles of the mouthparts and the salivary glands.

Vertebrates are the only chordate group to exhibit a proper brain. A slight swelling of the anterior end of the dorsal nerve cord is found in the lancelet, though it lacks the eyes and other complex sense organs comparable to those of vertebrates. Other chordates do not show any trends towards cephalisation. The central nervous system is based on a hollow nerve tube running along the length of the animal, from which the peripheral nervous system branches out to innervate the various systems.

It has two muscular rings or sphincters in its wall, one at the top and one at the bottom. The lower sphincter helps to prevent reflux of acidic stomach content. The esophagus has a rich blood supply and venous drainage. Its smooth muscle is innervated by involuntary nerves (sympathetic nerves via the sympathetic trunk and parasympathetic nerves via the vagus nerve) and in addition voluntary nerves (lower motor neurons) which are carried in the vagus nerve to innervate its striated muscle.

The somatic motor fibers that innervate the laryngeal and pharyngeal muscles are located in the nucleus ambiguus and emerge from the medulla in the cranial root of the accessory nerve. Fibers cross over to and join the vagus nerve in the jugular foramen. Sensory cell bodies are located in the inferior jugular ganglion, and the fibers terminate in the solitary nucleus. Parasympathetic fibers to segments of the trachea and esophagus in the neck originate in the dorsal nucleus of the vagus nerve.

Sympathetic motor neurons in the spinal cord are controlled by supranuclear pathways that descend through the brainstem and spinal cord. Interruption of the sympathetic chain at any level (from the brainstem to the ciliary ganglion) will produce pupillary constriction (miosis) and eyelid droop (ptosis) – the classic signs of Horner's syndrome. Sympathetic fibers from the superior cervical ganglion innervate blood vessels (vasoconstriction), sweat glands, and 4 eye muscles: the dilator pupillae, the superior tarsal muscle, the inferior tarsal muscle and the orbitalis.

These are inserted into the vagina and provide continuous, low dose and consistent drug levels in the vagina and throughout the body. Before the baby merges from the womb, an injection for pain control during childbirth may be administered through the vaginal wall and near the pudendal nerve. Because the pudendal nerve carries motor and sensory fibers that innervate the pelvic muscles, a pudendal nerve block relieves birth pain. The medicine does not harm the child, and is without significant complications.

The dopaminergic neurons from the ventral tegmental area that innervate the olfactory tubercle enable the tubercle to play roles in reward and arousal and appears to partially mediate cocaine reinforcement. The anteromedial portions of the tubercle have been shown to mediate some of the rewarding effects of drugs like cocaine and amphetamine. This has been shown in studies where rats learn to self-administer cocaine at significantly high rates into the tubercle. Injections of cocaine into the tubercle induce robust locomotion and rearing behavior in rats.

It is the only muscle supplied by the abducens nerve, cranial nerve VI. The abducens nerve exits the brainstem from the pons- medullary junction, and travels through the superior orbital fissure to innervate the lateral rectus muscle. The lateral rectus muscle is innervated through the tectospinal tract. This tract begins in the tectum region of the midbrain, and crosses to the contralateral side of the midbrain. The tectospinal tract descends through the brainstem to the upper spinal cord, but goes no further than the neck.

In the cortex, basket cells have sparsely branched axons giving off small pericellular, basket-shaped elaborations at several intervals along their length. Basket cells make up 5-10% of total neurons in the cortex. There are three types of basket cells in the cortex, the small, large and nest type: The axon of a small basket cell arborizes in the vicinity of that same cell's dendritic range, this axon is short. In contrast, large basket cells innervate somata in different cortical columns due to a long axon.

Upper motor neurons in the primary motor cortex send their axons to the brainstem and spinal cord to synapse on the lower motor neurons, which innervate the muscles. Damage to motor areas by chance of cortex can lead to certain types of motor neuron disease. This kind of damage results in loss of muscular power and precision rather than total paralysis. It functions as the center of sensory perception, memory, thoughts and judgement; the cerebrum also functions as the center of voluntary motor activities.

The cerebral ganglia, the largest within the animal's body, connect to the labial ganglia and buccal ganglia, thereby controlling the muscles of the mouth. They also innervate the two cephalic tentacles and the snout, governing motion of the head and its sensory organs. The cerebral ganglia are not located near the pleural and pedal ones, an arrangement called hypoathroid which is considered evolutionarily archaic: more "modern" molluscs tend to have the cerebral, pleural, and pedal ganglia situated centrally and more proximally to each other.

Therefore, neither length nor tension is likely to remain the same in muscles that contract during locomotor activity. In vertebrates, skeletal muscle contractions are neurogenic as they require synaptic input from motor neurons to produce muscle contractions. A single motor neuron is able to innervate multiple muscle fibers, thereby causing the fibers to contract at the same time. Once innervated, the protein filaments within each skeletal muscle fiber slide past each other to produce a contraction, which is explained by the sliding filament theory.

The glomus type I cells of the carotid body are innervated by the sensory neurons found in the inferior ganglion of the glossopharyngeal nerve. The carotid sinus nerve is the branch of the glossopharyngeal nerve which innervates them. Alternatively, the glomus type I cells of the aortic body are innervated by sensory neurons found in the inferior ganglion of the vagus nerve. Centrally the axons of neurons which innervate glomus type I cells synapse in the caudal portion of the solitary nucleus in the medulla.

The deep petrosal nerve is a branch of the internal carotid plexus which runs through the carotid canal lateral to the internal carotid artery. It enters the cartilaginous substance which fills the foramen lacerum, and joins with the greater petrosal nerve to form the nerve of the pterygoid canal, also known as the Vidian nerve. The deep petrosal nerve carries postganglionic sympathetic axons to the pterygopalatine ganglion, which pass through without synapsing. These axons innervate blood vessels and mucous glands of the head and neck.

Electrocytes also have an important structure called "stalk," which are tentacle or tube-like structures that extend out from each electrocyte. Different stalk-electrocyte systems have been observed, which include stalks that penetrate the electrocytes, innervate electrocytes from the posterior or anterior side. Multiple stalks from one electrocyte eventually fuse together to form a large stalk that receives innervation from spinal-electromotor neurons. Different morphological structures of the stalk/ electrocyte systems result in differences in electric current flow, which further lead to various waveforms.

The mandibular and maxillary branches of the trigeminal nerve (CN V) innervate the structures derived from the corresponding processes of the first arch. In some lower animals, each arch is supplied by two cranial nerves. The nerve of the arch itself runs along the cranial side of the arch and is called post-trematic nerve of the arch. Each arch also receives a branch from the nerve of the succeeding arch called the pre-trematic nerve which runs along the caudal border of the arch.

The gene is expressed in spindle-shaped cells located along nerve fibers between the auditory ganglion and sensory epithelium. These cells accompany neurites at the habenula perforata, the opening through which neurites extend to innervate hair cells. This and the pattern of expression of this gene in chicken inner ear paralleled the histologic findings of acidophilic deposits, consistent with mucopolysaccharide ground substance, in temporal bones from DFNA9 (autosomal dominant nonsyndromic sensorineural deafness 9) patients. Mutations that cause DFNA9 have been reported in this gene.

The central nervous system controls muscle spindle sensitivity via the fusimotor system. It consists of muscle spindles along with fusimotor neurons - beta motor neurons and gamma motor neurons. Because beta motor neurons innervate extrafusal as well as intrafusal muscle fibers, they are more specifically named skeletofusimotor neurons. Gamma motor neurons are the efferent (sending signals away from the central nervous system) part of the fusimotor system, whereas muscle spindles are the afferent part, as they send signals relaying information from muscles toward the spinal cord and brain.

Dynamic gamma motor neurons innervate the dynamic nuclear bag fibers (bag1 fibers), another type of nuclear bag fiber smaller than the static nuclear bag fibers. This type of gamma motor neuron can enhance the sensitivities of Ia sensory neurons. It is done so because the dynamic nuclear bag fibers, which are innervated by the dynamic gamma motor neurons, receive Ia sensory innervation. Furthermore, the firing of dynamic gamma motor neurons removes the slack in dynamic nuclear bags, bringing Ia fibers closer to the firing threshold.

The oculomotor nerve include axons of type GSE, general somatic efferent, which innervate skeletal muscle of the levator palpebrae superioris, superior rectus, medial rectus, inferior rectus, and inferior oblique muscles.(innervates all the extrinsic muscles except superior oblique and lateral rectus.) The nerve also includes axons of type GVE, general visceral efferent, which provide preganglionic parasympathetics to the ciliary ganglion. From the ciliary ganglion post ganglionic fibers pass through the short ciliary nerve to the constrictor pupillae of the iris and the cilliary muscles.

Gastrin-releasing peptide is a regulatory human peptide that elicits gastrin release and regulates gastric acid secretion and enteric motor function. The post-ganglionic fibers of the vagus nerve that innervate the G cells of the stomach release GRP, which stimulates the G cells to release gastrin. GRP is also involved in the biology of the circadian system, playing a role in the signaling of light to the master circadian oscillator in the suprachiasmatic nuclei of the hypothalamus. Furthermore, GRP seems to mediate certain aspects of stress.

Occipital nerve block is a procedure involving injection of steroids or anesthetics into regions of the greater occipital nerve and the lesser occipital nerve used to treat chronic headaches. These nerves are located in the back of the head near in the suboccipital triangle along the line between the inion and the mastoid process. They innervate muscles in the suboccipital and posterior scalp regions. The injection will either block pain signals or reduce swelling and inflammation in these regions depending on the choice of injection.

Most cases involve the cranial nerves, which innervate many small cranial muscles, such as the facial muscles and the extraocular muscles. This is in contrast to areas of body where miswiring of the larger muscles is less evident due to the size of the muscles. Synkinesis can also involve the upper limbs, especially hands which is quite rare, at 1 case in 1 million. In some cases, nerves improperly regenerate into glands, such as lacrimal glands, leading to a condition known as crocodile tears or Bogorad's syndrome.

Nerves involved in the resizing of the pupil connect to the pretectal nucleus of the high midbrain, bypassing the lateral geniculate nucleus and the primary visual cortex. From the pretectal nucleus neurons send axons to neurons of the Edinger-Westphal nucleus whose visceromotor axons run along both the left and right oculomotor nerves. Visceromotor nerve axons (which constitute a portion of cranial nerve III, along with the somatomotor portion derived from the Edinger-Westphal nucleus) synapse on ciliary ganglion neurons, whose parasympathetic axons innervate the iris sphincter muscle, producing miosis.

These pruritogens, like histamine, also cause other immune cells to secrete further pruritogens in an effort to cause more itching to physically remove parasitic invaders. In terms of intestinal and bronchial parasites, vomiting, coughing, and diarrhea can also be caused by nociceptor stimulation in infected tissues, and nerve impulses originating from the brain stem that innervate respective smooth muscles. Eosinophils in response to capsaicin, can trigger further sensory sensitization to the molecule. Patients with chronic cough also have an enhanced cough reflex to pathogens even if the pathogen has been expelled.

The vestibulospinal tract is part of the "extrapyramidal system" of the central nervous system. In human anatomy, the extrapyramidal system is a neural network located in the brain that is part of the motor system involved in the coordination of movement. The system is called "extrapyramidal" to distinguish it from the tracts of the motor cortex that reach their targets by traveling through the "pyramids" of the medulla. The pyramidal pathways, such as corticospinal and some corticobulbar tracts, may directly innervate motor neurons of the spinal cord or brainstem.

The sacral sympathetic nerves arise from the sacral part of the sympathetic trunk, emerging anteriorly from the ganglia. They travel to their corresponding side's inferior hypogastric plexus, where the preganglionic nerve fibers synapse with the postganglionic sympathetic neurons, whose fibers ascend to the superior hypogastric plexus, the aortic plexus and the inferior mesenteric plexus, where they are distributed to the anal canal. From the inferior hypogastric plexus, they also innervate pelvic organs and vessels. The sacral sympathetic nerves contain a mix of preganglionic and postganglionic sympathetic fibers, but mostly preganglionic.

In the upper part of the superior mesenteric plexus close to the origin of the superior mesenteric artery is a ganglion, the superior mesenteric ganglion. The superior mesenteric ganglion is the synapsing point for one of the pre- and post-synaptic nerves of the sympathetic division of the autonomous nervous system. Specifically, contributions to the Superior Mesenteric Ganglion arise from the lesser splanchnic nerve, which arises from the sympathetic chain of T10-11. This nerve goes on to innervate the jejunum, ileum, ascending colon and the transverse colon.

Stimulation of specialized pain-sensitive nerve fibers (nociceptors) that innervate bone tissue leads to the sensation of bone pain. Bone pain originates from both the periosteum and the bone marrow which relay nociceptive signals to the brain creating the sensation of pain. Bone tissue is innervated by both myelinated (A beta and A delta fiber) and unmyelinated (C fiber) sensory neurons. In combination, they can provide an initial burst of pain, initiated by the faster myelinated fibers, followed by a slower and longer-lasting dull pain initiated by unmyelinated fibers.

In skeletal muscles, the junctions are mostly of the same distance and size because they innervate such definite structures of muscle fibers. In the Autonomic Nervous System however, these neuromuscular junctions are much less well defined. Analysis of non-noradrenergic/non- cholinergic (NANC) transmission at single varicosities or swellings indicates that individual synapses possess different probabilities for the secretion of transmitter as well as different complements of autoreceptors and mixtures of post-junctional receptor subunits. There is then a local determination of the quantitative properties of single synapses.

A core motor control issue is coordinating the various components of the motor system to act in unison to produce movement. The motor system is highly complex, composed of many interacting parts at many different organizational levels Peripheral neurons receive input from the central nervous system and innervate the muscles. In turn, muscles generate forces which actuate joints. Getting the pieces to work together is a challenging problem for the motor system and how this problem is resolved is an active area of study in motor control research.

Two additional ways to decrease fasciculation are to secrete an anti-adhesive factor, such as Beat-1a, from the growth cone and to post-translationally alter adhesion molecules prior to their insertion into the growth cone membranes. The actual target during target selection can also play an important role in the defasciculation of axons that will eventually innervate. In target muscle, the immunoglobulin superfamily protein Sidestep signals for the defasciculation of motor neuron branches and then attracts those branches to the target muscle. Importantly, Sidestep is present and expressed in all muscles.

Improvement indicates that the cause of lameness was from a structure desensitized by the nerve block. Nerve blocks are performed in a step-wise fashion, beginning at the most distal (lower) part of the limb and moving upward. This is due to the fact that blocking a nerve higher up will desensitize everything it innervates distal to the blocking location. For example, blocking the leg at the level of the fetlock will also block the entire foot, since the nerve fibers that innervate the foot are inhibited when they travel through the fetlock area.

However, this did not impair circadian photo entrainment. This demonstrated that the M1 ipRGC consist of molecularly distinct subpopulations that innervate different brain regions and execute specific light-induced functions. This isolation of a 'labeled line' consisting of differing molecular and functional properties in a highly specific ipRGC subtype was an important first for the field. It also underscored the extent to which molecular signatures can be used to distinguish between RGC populations that would otherwise appear the same, which in turn facilitates further investigation into their specific contributions to visual processing.

The celiac ganglia or coeliac ganglia are two large irregularly shaped masses of nerve tissue in the upper abdomen. Part of the sympathetic subdivision of the autonomic nervous system (ANS), the two celiac ganglia are the largest ganglia in the ANS, and they innervate most of the digestive tract. They have the appearance of lymph glands and are placed on either side of the midline in front of the crura of the diaphragm, close to the suprarenal glands (also called adrenal glands). The ganglion on the right side is placed behind the inferior vena cava.

The spinal cord contains a series of segmental ganglia, each giving rise to motor and sensory nerves that innervate a portion of the body surface and underlying musculature. On the limbs, the layout of the innervation pattern is complex, but on the trunk it gives rise to a series of narrow bands. The top three segments belong to the brain, giving rise to the forebrain, midbrain, and hindbrain. Bilaterians can be divided, based on events that occur very early in embryonic development, into two groups (superphyla) called protostomes and deuterostomes.

The numb gene protein product controls binary cell fate decisions in the peripheral and central nervous systems of both invertebrates and mammals during neurogenesis. During cell division, Numb is asymmetrically localized to one end of the progenitor cell and subsequently segregates to only one daughter cell where it intrinsically determines cell fate. Numb protein signaling plays a key role in binary cell fate decisions following asymmetric cell divisions. One daughter cell, generally that receiving the Numb, is able to adopt a neuronal fate and innervate the developing nervous system.

The type I fibres are thicker than the type II fibres and may also differ in how they innervate the inner hair cells. Neurons with large calyceal endings ensure preservation of timing information throughout the ITD pathway. Next in the pathway is the cochlear nucleus, which receives mainly ipsilateral (that is, from the same side) afferent input. The cochlear nucleus has three distinct anatomical divisions, known as the antero-ventral cochlear nucleus (AVCN), postero- ventral cochlear nucleus (PVCN) and dorsal cochlear nucleus (DCN) and each have different neural innervations.

Without gamma motor neurons, muscle spindles would be very loose as the muscle contracts more. This does not allow for muscle spindles to detect a precise amount of stretch since it is so limp. However, with alpha gamma co-activation and both alpha and gamma neurons firing, muscle fibers within the muscle spindles are pulled parallel to the extrafusal contraction causing the muscle movement. The firing of gamma motor neurons in sync with alpha motor neurons pulls muscle spindles from polar ends of the fibers as this is where gamma motor neurons innervate the muscle.

Thalamocortical (TC) fibers have been referred to as one of the two constituents of the isothalamus, the other being micro neurons. Thalamocortical fibers have a bush or tree-like appearance as they extend into the internal capsule and project to the layers of the cortex. The main thalamocortical fibers extend from different nuclei of the thalamus and project to the visual cortex, somatosensory (and associated sensori-motor) cortex, and the auditory cortex in the brain. Thalamocortical radiations also innervate gustatory and olfactory pathways, as well as pre-frontal motor areas.

The spinal cord contains a series of segmental ganglia, each giving rise to motor and sensory nerves that innervate a portion of the body surface and underlying musculature. On the limbs, the layout of the innervation pattern is complex, but on the trunk it gives rise to a series of narrow bands. The top three segments belong to the brain, giving rise to the forebrain, midbrain, and hindbrain. Bilaterians can be divided, based on events that occur very early in embryonic development, into two groups (superphyla) called protostomes and deuterostomes.

It acts to flex, adduct, and abduct the thumb, and is therefore also able to oppose the thumb. The superficial head is innervated by the median nerve, while the deep head is innervated by the ulnar nerve (C8-T1). Due to a common interconnection between the median and ulnar nerves in the hand (Riche-Cannieu interconnection), the median nerve may innervate the flexor pollicis brevis in 35% of people. It is innervated by the ulnar nerve in 50% of people and by both the median and ulnar nerves in 15%.

Alpha motor neurons are further differentiated into subclasses that demonstrate distinct physiological characteristics. Fast-twitch, fatigable (FF) motor neurons are the largest (and therefore the fastest in propagating signals) of the alpha- motor neurons; FR (fast-twitch, fatigue-resistant) neurons are of intermediate size, and slow-twitch, fatigue-resistant (S) neurons are the smallest subclass. In addition to signalling velocity, these differential sizes also form the physiological basis of the size principle. Due to their relatively small axonal diameter, S type neurons, which innervate smaller muscle fibers, require a smaller input potential to reach threshold.

Simplified diagram of frontal cortex to striatum to thalamus pathways – frontostriatal circuit glutamatergic pathways, refer to inhibitory GABAergic pathways and refer to dopaminergic pathways that are excitatory on the direct pathway and inhibitory on the indirect pathway. The largest connection is from the cortex, in terms of cell axons. Many parts of the neocortex innervate the dorsal striatum. The cortical pyramidal neurons projecting to the striatum are located in layers II-VI, with the most dense projections come from layer V. They end mainly on the dendritic spines of the spiny neurons.

In general, there is a greater density of dopaminergic input to the dorsolateral striatum. Each dopamine neuron has an extremely large unmyelinated axonal arborization which can innervate up to 6% of the striatal volume in a rat. Although all SNc dopamine cells project to both the striosome (or patch) and matrix neurochemical compartments of the striatum, most of the axonal territory of a dorsal tier neuron is in the matrix compartment while the majority of the axonal field of ventral tier neurons is in the striosomes. Nigrostriatal dopamine axons can also give rise to axon collaterals that project to other brain regions.

The meningeal branches of the spinal nerves (also known as recurrent meningeal nerves, sinuvertebral nerves, or recurrent nerves of Luschka) are a number of small nerves that branch from the segmental spinal nerve near the origin of the anterior and posterior rami, but before the rami communicantes; rami communicantes are branches which communicate between the spinal nerves and the sympathetic trunk. They then re-enter the intervertebral foramen, and innervate the facet joints, the anulus fibrosus of the intervertebral disc, and the ligaments and periosteum of the spinal canal, carrying pain sensation. The nucleus pulposus of the intervertebral disk has no pain innervation.

The nervous system consists of a dorsal cerebral ganglion or brain above the oesophagus and a nerve ring around the oesophagus, which links the brain with the single ventral nerve cord that runs the length of the body. Lateral nerves lead off this to innervate the muscles of the body wall. In some species, there are simple light-sensitive ocelli associated with the brain. Two organs, likely functioning as a unit for chemoreception are located near its anterior margin; the non-ciliated cerebral organ, which possesses bipolar sensory cells, and the nuchal organ, located posterior to the brain.

In cases that have not responded to corticosteroid treatment, FESS can be used to decompress the orbital region by removing the ethmoid air cells and lamina papyracea. Bones of the orbital cavity or portions of the orbital floor may also be removed. The endoscopic approach to FESS is a less invasive method than open sinus surgery, which allows patients to be more comfortable during and after the procedure. Entering the surgical field via the nose, rather than through an incision in the mouth as in the previous Caldwell-Luc method, decreases risk of damaging nerves which innervate the teeth.

The set point temperature of the body will remain elevated until PGE2 is no longer present. PGE2 acts on neurons in the preoptic area (POA) through the prostaglandin E receptor 3 (EP3). EP3-expressing neurons in the POA innervate the dorsomedial hypothalamus (DMH), the rostral raphe pallidus nucleus in the medulla oblongata (rRPa), and the paraventricular nucleus (PVN) of the hypothalamus . Fever signals sent to the DMH and rRPa lead to stimulation of the sympathetic output system, which evokes non-shivering thermogenesis to produce body heat and skin vasoconstriction to decrease heat loss from the body surface.

Lower motor neurons (LMNs) are motor neurons located in either the anterior grey column, anterior nerve roots (spinal lower motor neurons) or the cranial nerve nuclei of the brainstem and cranial nerves with motor function (cranial nerve lower motor neurons). All voluntary movement relies on spinal lower motor neurons, which innervate skeletal muscle fibers and act as a link between upper motor neurons and muscles. Cranial nerve lower motor neurons control movements of the eyes, face and tongue, and contribute to chewing, swallowing and vocalization. Damage to the lower motor neurons can lead to flaccid paralysis, absent deep tendon reflexes and muscle atrophy.

In humans, temperature sensation enters the spinal cord along the axons of Lissauer's tract that synapse on second order neurons in grey matter of the dorsal horn, one or two vertebral levels up. The axons of these second order neurons then decussate, joining the spinothalamic tract as they ascend to neurons in the ventral posterolateral nucleus of the thalamus. In mammals, temperature receptors innervate various tissues including the skin (as cutaneous receptors), cornea and urinary bladder. Neurons from the pre-optic and hypothalamic regions of the brain that respond to small changes in temperature have also been described, providing information on core temperature.

Of all waveform characteristics, P1-N1 amplitude is the most reliable and clinically relevant. cVEMP amplitude is linearly dependent upon stimulus intensity and is most reliably elicited with a loud (generally at or above 95 dB nHL) click or tone burst. The cVEMP can also be said to be low- frequency tuned, with largest amplitudes in response to 500–750 Hz tonebursts. This myogenic potential is felt to assess saccular function, because the response is present in completely deafened ears and because it is routed through the inferior vestibular nerve, which is known to dominantly innervate the saccule. .

Both parameters are carried by each fiber of the auditory nerve.Zupanc, Gunther K.H. Behavioral Neurobiology: An integrative approach. Oxford University Press, New York: 2004, 142-149 The fibers of the auditory nerve innervate both cochlear nuclei in the brainstem, the cochlear nucleus magnocellularis (mammalian anteroventral cochlear nucleus) and the cochlear nucleus angularis (see figure; mammalian posteroventral and dorsal cochlear nuclei). The neurons of the nucleus magnocellularis phase-lock, but are fairly insensitive to variations in sound pressure, while the neurons of the nucleus angularis phase-lock poorly, if at all, but are sensitive to variations in sound pressure.

Crutch paralysis is a form of paralysis which can occur when either the radial nerve or part of the brachial plexus, containing various nerves that innervate sense and motor function to the arm and hand, is under constant pressure, such as by the use of a crutch. This can lead to paralysis of the muscles innervated by the compressed nerve. Generally, crutches that are not adjusted to the correct height can cause the radial nerve to be constantly pushed against the humerus. This can cause any muscle that is innervated by the radial nerve to become partially or fully paralyzed.

Acoustic stimulation of the inner hair cells sends a neural signal to the posteroventral cochlear nucleus (PVCN), and the axons of the neurons from the PVCN cross the brainstem to innervate the contralateral MOC neurons. In most mammals, the MOC neurons predominantly project to the contralateral side (forming the ipsilateral reflex), with the remainder projecting to the ipsilateral side (forming the contralateral reflex). The strength of the reflex is weakest for pure tones, and becomes stronger as the bandwidth of the sound is increased (Berlin et al., 1993), hence the maximum MOCS response is observed for broadband noise (Guinan et al.

This genus of burrowing multituberculate mammals provides one of the earliest unequivocal examples of mammal fur (Lower Cretaceous fossils of Eomaia, Volaticotherium and Castorocauda with the fur preserved still attached are currently the oldest). Indirect evidence suggest that hair first appeared on non-mammalian therapsids (Therapsida), back in the Triassic or even earlier. This is inferred from small hollows on the bone of the snout similar to holes in the skulls of cats which provide space for concentrations of nerves and blood vessels that innervate prominent whiskers (specialized hairs). This adaptation allows cats to use their whiskers as effective tactile sensory organs.

However, studies have identified that gait patterns in deafferented or immobilized animals are more simplistic than in neurologically intact animals. (Deafferentation and immobilization are experimental preparations of animals to study neural control. Deafferentation involves transecting the dorsal roots of the spinal cord that innervate the animal's limbs which impedes transmission of sensory information while keeping motor innervation of muscles intact. In contrast, immobilization involves injecting an acetylcholine inhibitor which impedes the transmission of motor signals while sensory input is unaffected.) The complexity of gait arises from the need to adapt to expected and unexpected changes in the environment (e.g.

A single motor neuron may innervate many muscle fibres and a muscle fibre can undergo many action potentials in the time taken for a single muscle twitch. As a result, if an action potential arrives before a twitch has completed, the twitches can superimpose on one another, either through summation or a tetanic contraction. In summation, the muscle is stimulated repetitively such that additional action potentials coming from the somatic nervous system arrive before the end of the twitch. The twitches thus superimpose on one another, leading to a force greater than that of a single twitch.

In invertebrates, depending on the neurotransmitter released and the type of receptor it binds, the response in the muscle fiber could be either excitatory or inhibitory. For vertebrates, however, the response of a muscle fiber to a neurotransmitter can only be excitatory, in other words, contractile. Muscle relaxation and inhibition of muscle contraction in vertebrates is obtained only by inhibition of the motor neuron itself. This is how muscle relaxants work by acting on the motor neurons that innervate muscles (by decreasing their electrophysiological activity) or on cholinergic neuromuscular junctions, rather than on the muscles themselves.

The major input to the cochlear nucleus is from the auditory nerve, a part of cranial nerve VIII (the vestibulocochlear nerve). The auditory nerve fibers form a highly organized system of connections according to their peripheral innervation of the cochlea. Axons from the spiral ganglion cells of the lower frequencies innervate the ventrolateral portions of the ventral cochlear nucleus and lateral-ventral portions of the dorsal cochlear nucleus. The axons from the higher frequency organ of corti hair cells project to the dorsal portion of the ventral cochlear nucleus and the dorsal-medial portions of the dorsal cochlear nucleus.

A brachial plexus injury (BPI), also known as brachial plexus lesion, is an injury to the brachial plexus, the network of nerves that conducts signals from the spinal cord to the shoulder, arm and hand. These nerves originate in the fifth, sixth, seventh and eighth cervical (C5–C8), and first thoracic (T1) spinal nerves, and innervate the muscles and skin of the chest, shoulder, arm and hand. Brachial plexus injuries can occur as a result of shoulder trauma, tumours, or inflammation. The rare Parsonage–Turner syndrome causes brachial plexus inflammation without obvious injury, but with nevertheless disabling symptoms.

Bone metabolism can be regulated by central sympathetic outflow, since sympathetic pathways innervate bone tissue. A number of brain- signalling molecules (neuropeptides and neurotransmitters) have been found in bone, including adrenaline, noradrenaline, serotonin, calcitonin gene-related peptide, vasoactive intestinal peptide and neuropeptide Y. Leptin binds to its receptors in the hypothalamus, where it acts through the sympathetic nervous system to regulate bone metabolism. Leptin may also act directly on bone metabolism via a balance between energy intake and the IGF-I pathway. There is a potential for treatment of diseases of bone formation - such as impaired fracture healing - with leptin.

Thalamic interneurons process sensory information and signal different regions of the thalamic nuclei. These nuclei extend to relay cells, which in turn innervate distinct areas of the cortex via thalamocortical fibers. Either specifically or nonspecifically, TC relay cells project specifically to organized areas of the cortex directly and nonspecifically project to large areas of cortex through the innervation of many interconnected collateral axons. According to Jones (2001) there are two primary types of relay neurons in the thalamus of primates–core cells and matrix cells–each creating distinct pathways to various parts and layers throughout the cerebral cortex.

However, in contrast to simple convergence, the SC integrates information to create an output that differs from the sum of its inputs. Following a phenomenon labelled the 'spatial rule', neurons are excited if stimuli from multiple modalities fall on the same or adjacent receptive fields, but are inhibited if the stimuli fall on disparate fields. Excited neurons may then proceed to innervate various muscles and neural structures to orient an individual's behaviour and attention toward the stimulus. Neurons in the SC also adhere to the 'temporal rule', in which stimulation must occur within close temporal proximity to excite neurons.

As in the brainstem, higher segments of the spinal cord contain α-MNs that innervate muscles higher on the body. For example, the biceps brachii muscle, a muscle of the arm, is innervated by α-MNs in spinal cord segments C5, C6, and C7, which are found rostrally in the spinal cord. On the other hand, the gastrocnemius muscle, one of the muscles of the leg, is innervated by α-MNs within segments S1 and S2, which are found caudally in the spinal cord. Alpha motor neurons are located in a specific region of the spinal cord's gray matter.

Muscle fibers secrete a limited amount of neurotrophic factors capable of sustaining only a fraction of the α-MNs that initially project to the muscle fiber. Those α-MNs that do not receive sufficient neurotrophic factors will undergo apoptosis, a form of programmed cell death. Because they innervate many muscles, some clusters of α-MNs receive high concentrations of neurotrophic factors and survive this stage of neuronal pruning. This is true of the α-MNs innervating the upper and lower limbs: these α-MNs form large cell columns that contribute to the cervical and lumbar enlargements of the spinal cord.

The lateral pectoral nerve provides motor innervation to the pectoralis major. Although this nerve is described as mostly motor, it also has been considered to carry proprioceptive and nociceptive fibers. It arises either from the lateral cord or directly from the anterior divisions of the upper and middle trunks of the brachial plexus, unlike the medial pectoral nerve, which derives from the medial cord (or directly from the anterior division of the lower trunk). It splits into four to seven branches that pierce the clavipectoral fascia to innervate the entire pectoralis major or its superior portion.

It consists of descending fibers that arise from cells in the motor area of the ipsilateral cerebral hemisphere. The impulse travels from these upper motor neurons (located in the pre-central gyrus of the brain) through the anterior column. In contrast to the fibers for the lateral corticospinal tract, the fibers for the anterior corticospinal tract do not decussate at the level of the medulla oblongata, although they do cross over in the spinal level they innervate. They then synapse at the anterior horn with the lower motor neuron which then synapses with the target muscle at the motor end plate.

These neurons disappear during postnatal development and are important in establishing the correct wiring and functional maturation of the cerebral cortex. Subplate neurons appear to be selectively sensitive to injury (such as hypoxia) which in humans are associated with motor and cognitive defects . Subplate neurons are the first cortical neurons to receive synaptic inputs from thalamic axons, establishing a temporary link between thalamic axons and their final target in layer IV.. Later, thalamic axons invade layer IV where they innervate layer IV neurons. In the visual system thalamic axons to layer IV form ocular dominance columns and this segregation of thalamic axons is impaired if subplate neurons are missing .

The acute porphyrias are acute intermittent porphyria (AIP), variegate porphyria (VP), aminolevulinic acid dehydratase deficiency porphyria (ALAD) and hereditary coproporphyria (HCP). These diseases primarily affect the nervous system, resulting in episodic crises known as acute attacks. The major symptom of an acute attack is abdominal pain, often accompanied by vomiting, hypertension (elevated blood pressure), and tachycardia (an abnormally rapid heart rate). The most severe episodes may involve neurological complications: typically motor neuropathy (severe dysfunction of the peripheral nerves that innervate muscle), which leads to muscle weakness and potentially to quadriplegia (paralysis of all four limbs) and central nervous system symptoms such as seizures and coma.

The male lateral horn has abundant connections with the projecting neurons that come from the DA1, VA1lm and VL2a glomeruli of the antenal lobe (all of which are also larger in males). Each of these glomeruli are associated with the specific olfactory neurons that pick up pheromones. In moths the male-specific projecting pheromone-processing neurons innervate with glomeruli outside of the macroglomerular complex of the antennal lobe. Other studies in drosophila found that it is not just the neurons responsible for incoming information that are sexually dimorphic but also the lateral horn neurons that are sending information to the rest of the fly.

Virus infections usually begin in the peripheral tissues, and can invade the mammalian system by spreading into the peripheral nervous system and more rarely the CNS. CNS is protected by effective immune responses and multi-layer barriers, but some viruses enter with high-efficiency through the bloodstream and some by directly infecting the nerves that innervate the tissues. Most viruses that enter can be opportunistic and accidental pathogens, but some like herpes viruses and rabies virus have evolved in time to enter the nervous system efficiently, by exploiting the neuronal cell biology. While acute viral diseases come on quickly, chronic viral conditions have long incubation periods inside the body.

This is immediately sensed by the carbon dioxide chemoreceptors on the brain stem. The respiratory centers respond to this information by causing the rate and depth of breathing to increase to such an extent that the partial pressures of carbon dioxide and oxygen in the arterial blood return almost immediately to the same levels as at rest. The respiratory centers communicate with the muscles of breathing via motor nerves, of which the phrenic nerves, which innervate the diaphragm, are probably the most important. Automatic breathing can be overridden to a limited extent by simple choice, or to facilitate swimming, speech, singing or other vocal training.

Although the spinal cord cell bodies end around the L1/L2 vertebral level, the spinal nerves for each segment exit at the level of the corresponding vertebra. For the nerves of the lower spinal cord, this means that they exit the vertebral column much lower (more caudally) than their roots. As these nerves travel from their respective roots to their point of exit from the vertebral column, the nerves of the lower spinal segments form a bundle called the cauda equina. There are two regions where the spinal cord enlarges: Cervical enlargement - corresponds roughly to the brachial plexus nerves, which innervate the upper limb.

A subcortical loop exists within the brain linking upper motor neurons originating in the primary motor and pre-motor cortices and the brainstem, with the basal ganglia. These upper motor neurons eventually initiate movement by controlling the activity of lower motor neurons, located in the brainstem and spinal cord, and project out to innervate the muscles in the body. Upper motor neurons also modulate activity of local circuit neurons, whose synapses are a large input to these lower motor neurons, in turn affecting subsequent movement. Thus, the basal ganglia indirectly influence movement via regulation of the activity of the upper motor neurons, which ultimately determine activity of the lower motor neurons.

The frontal branch passes through the orbit superiorly, then reenters the frontal bone briefly before exiting above the orbit through the superior orbital fissure and the supraorbital notch to provide sensory innervation for the skin of the forehead and scalp. The lacrimal nerve passes through the orbit superiorly to innervate the lacrimal gland. The nasociliary branch gives off several sensory branches to the orbit and then continues out through the anterior ethmoidal foramen, where it enters the nasal cavity and provides innervation for much of the anterior nasal mucosa. It also gives off a branch which exits through the nasal bones to form the external nasal nerve.

The cochlear nuclear (CN) complex comprises two cranial nerve nuclei in the human brainstem, the ventral cochlear nucleus (VCN) and the dorsal cochlear nucleus (DCN). The ventral cochlear nucleus is unlayered whereas the dorsal cochlear nucleus is layered. Auditory nerve fibers, fibers that travel through the auditory nerve (also known as the cochlear nerve or eighth cranial nerve) carry information from the inner ear, the cochlea, on the same side of the head, to the nerve root in the ventral cochlear nucleus. At the nerve root the fibers branch to innervate the ventral cochlear nucleus and the deep layer of the dorsal cochlear nucleus.

Supraspinal vasomotor neurons send projections to the intermediolateral cell column, which is composed of sympathetic preganglionic neurons (SPN) through the T1-L2 segments. The supraspinal neurons act on the SPN and its tonic firing, modulating its action on the peripheral sympathetic chain ganglia and the adrenal medulla. The sympathetic ganglia act directly on the blood vessels they innervate throughout the body, controlling vessel diameter and resistance, while the adrenal medulla indirectly controls the same action through the release of epinephrine and norepinephrine. The descending autonomic pathways, which are responsible for the supraspinal communication with the SPN, are interrupted resulting in decreased sympathetic outflow below the level of the injury.

They innervate the heart via sympathetic cardiac nerves that increase cardiac activity and vagus (parasympathetic) nerves that slow cardiac activity. Parasympathetic stimulation originates from the cardioinhibitory region of the brain with impulses traveling via the vagus nerve (cranial nerve X). The vagus nerve sends branches to both the SA and AV nodes, and to portions of both the atria and ventricles. Parasympathetic stimulation releases the neurotransmitter acetylcholine (ACh) at the neuromuscular junction. ACh slows HR by opening chemical- or ligand-gated potassium ion channels to slow the rate of spontaneous depolarization, which extends repolarization and increases the time before the next spontaneous depolarization occurs.

More specifically: # innervation of taste buds on the posterior 1/3 of tongue # general sensory innervation of posterior 1/3 of tongue, soft palate, palatine tonsils, upper pharynx and Eustachian tubes # innervation of baroreceptor cells in the carotid sinus # innervation of glomus type I chemoreceptor cells in the carotid body The central processes of the neurons which provide taste sensation synapse in the rostral portion of the solitary nucleus (also called the gustatory nucleus). The central processes of the neurons which provide general sensory information synapse in the spinal trigeminal nucleus. Finally, the central processes of the neurons which innervate the carotid sinus and carotid body synapse in the caudal portion of the solitary nucleus.

The pedal ganglia are located low and close together in the back of the head region, with the more widely spaced pleural ganglia positioned slightly forward of them and above. Each pedal ganglion gives off a broad pedal nerve cord that runs the length of the animal's body beneath the visceral mass and together control its foot and shell muscle bundles. Each of the pleural ganglia connects to a statocyst that allows the limpet to orient itself. The pleural ganglia also innervate the pericardium (via the pericardial nerve cord) and the visceral ganglion, as well as the anterior and posterior sets of pallial nerves which travel through the mantle and surround the animal's head and sides respectively.

She noted that pathological destruction of nerve cells in the ciliary ganglion that is found in all cases of Adie pupil. In her own words: : Let’s say that in a given fresh Adie’s pupil, a random 70% of the cells in the ciliary ganglion stop working; and that, in a couple of months, these neurons re-grow and randomly re-innervate both intraocular sphincters (the ciliary muscle and the iris sphincter). Some parasympathetic light-reaction neurons that were originally destined for the iris sphincter will end up innervating the ciliary muscle. But there will not be enough of them to budge that big muscle, so there will be no detectable accommodation with exposure to light.

An organ is a group of tissues with similar functions. Plant life and animal life rely on many organs that coexist in organ systems. A given organ's tissues can be broadly categorized as parenchyma, the tissue peculiar to (or at least archetypal of) the organ and that does the organ's specialized job, and stroma, the tissues with supportive, structural, connective, or ancillary functions. For example, in a gland, the tissue that makes the hormones is the parenchyma, whereas the stroma includes the nerves that innervate the parenchyma, the blood vessels that oxygenate and nourish it and carry away its metabolic wastes, and the connective tissues that provide a suitable place for it to be situated and anchored.

The cauda equina () is a bundle of spinal nerves and spinal nerve rootlets, consisting of the second through fifth lumbar nerve pairs, the first through fifth sacral nerve pairs, and the coccygeal nerve, all of which arise from the lumbar enlargement and the conus medullaris of the spinal cord. The cauda equina occupies the lumbar cistern, a subarachnoid space inferior to the conus medullaris. The nerves that compose the cauda equina innervate the pelvic organs and lower limbs to include motor innervation of the hips, knees, ankles, feet, internal anal sphincter and external anal sphincter. In addition, the cauda equina extends to sensory innervation of the perineum and, partially, parasympathetic innervation of the bladder.

The motor domain in the dorsal portion of the dentate contains output channels that control both generation and control of movement, as well as neurons that innervate premotor areas in the frontal lobe. The nonmotor domain contains output channels involved in cognition and visuospatial function, and projections to the prefrontal and posterior parietal cortical areas within this region are clustered into distinct regions with little overlap. These areas are activated during tasks involving short-term working memory, rule-based learning, and higher executive function-like planning. Although the ventral aspect of the dentate has been shown to be involved in acquisition of information, whether it is involved in retention and storage remains unclear.

The dorsal nucleus of vagus nerve (or posterior nucleus of vagus nerve or dorsal vagal nucleus or nucleus dorsalis nervi vagi or nucleus posterior nervi vagi) is a cranial nerve nucleus for the vagus nerve in the medulla that lies ventral to the floor of the fourth ventricle. It mostly serves parasympathetic vagal functions in the gastrointestinal tract, lungs, and other thoracic and abdominal vagal innervations. The cell bodies for the preganglionic parasympathetic vagal neurons that innervate the heart reside in the nucleus ambiguus. Additional cell bodies are found in the nucleus ambiguus, which give rise to the branchial efferent motor fibers of the vagus nerve (CN X) terminating in the laryngeal, pharyngeal muscles, and musculus uvulae.

The geniculate ganglion (from Latin genu, for "knee") is a collection of pseudounipolar sensory neurons of the facial nerve located in the facial canal of the head. It receives fibers from the motor, sensory, and parasympathetic components of the facial nerve and sends fibers that will innervate the lacrimal glands, submandibular glands, sublingual glands, tongue, palate, pharynx, external auditory meatus, stapedius, posterior belly of the digastric muscle, stylohyoid muscle, and muscles of facial expression. The geniculate ganglion contains special sensory neuronal cell bodies for taste, from fibers coming up from the tongue through the chorda tympani and from fibers coming up from the roof of the palate through the greater petrosal nerve. Sensory and parasympathetic inputs are carried into the geniculate ganglion via the nervus intermedius.

In cardiac uses, it works as a nonselective muscarinic acetylcholinergic antagonist, increasing firing of the sinoatrial node (SA) and conduction through the atrioventricular node (AV) of the heart, opposes the actions of the vagus nerve, blocks acetylcholine receptor sites, and decreases bronchial secretions. In the eye, atropine induces mydriasis by blocking contraction of the circular pupillary sphincter muscle, which is normally stimulated by acetylcholine release, thereby allowing the radial iris dilator muscle to contract and dilate the pupil. Atropine induces cycloplegia by paralyzing the ciliary muscles, whose action inhibits accommodation to allow accurate refraction in children, helps to relieve pain associated with iridocyclitis, and treats ciliary block (malignant) glaucoma. The vagus (parasympathetic) nerves that innervate the heart release acetylcholine (ACh) as their primary neurotransmitter.

Withdrawal reflex The withdrawal reflex is a reflex that protects an organism from harmful stimuli. This reflex occurs when noxious stimuli activate nociceptors that send an action potential to nerves in the spine, which then innervate effector muscles and cause a sudden jerk to move the organism away from the dangerous stimuli. The withdrawal reflex involves both the nervous and immune systems. When the action potential travels back down the spinal nerve network, another impulse travels to peripheral sensory neurons that secrete amino acids and neuropeptides like calcitonin gene- related peptide (CGRP) and Substance P. These chemicals act by increasing the redness, swelling of damaged tissues, and attachment of immune cells to endothelial tissue, thereby increasing the permeability of immune cells across capillaries.

The varied accuracy of damaged axons regenerating and reaching their original target end is a large reason that functional recovery of damaged nerves is such a variable in the peripheral nervous system. The understanding of what Schwann Cell tube axons tend to reinnervate has implications for whether a nerve will be able to become functional again after damage. If the axon is a subcutaneous axon and ends up in a motor Schwann Cell tube, it will not be able to innervate the muscle it ends up connected to. Thus, understanding how axons do reinnervate, and how motor axons can be pushed towards the correct regeneration site is an area of study that is extremely beneficial in helping to advance nerve repair in the PNS system.

Once within the target area, the growing axon must locate with precision the appropriate cell to innervate. They do so by following gradients of cell surface molecules that serve as chemoattractants and repellents to the growth cone. This perspective is an evolution of the Chemoaffinity Hypothesis posited by Roger Sperry in the 1960s. Sperry studied how the neurons in the visual systems of amphibians and goldfish form topographic maps in the brain, noting that if the optic nerve is crushed and allowed to regenerate, the axons will trace back the same patterns of connections. Sperry hypothesized that the target cells carried “identification tags” that would guide the growing axon, which we now know as recognition molecules that bind the growth cone along a gradient.

Mushroom Bodies of the Fruit Fly These regions are often modular and serve a particular role within the general systemic pathways of the nervous system. For example, the hippocampus is critical for forming memories in connection with many other cerebral regions. The peripheral nervous system also contains afferent or efferent nerves, which are bundles of fibers that originate from the brain and spinal cord, or from sensory or motor sorts of peripheral ganglia, and branch repeatedly to innervate every part of the body. Nerves are made primarily of the axons or dendrites of neurons (axons in case of efferent motor fibres, and dendrites in case of afferent sensory fibres of the nerves), along with a variety of membranes that wrap around and segregate them into nerve fascicles.

The most significant impact of magnetic resonance neurography is on the evaluation of the large proximal nerve elements such as the brachial plexus (the nerves between the cervical spine and the underarm that innervate shoulder, arm and hand), the lumbosacral plexus (nerves between the lumbosacral spine and legs), the sciatic nerve in the pelvis, as well as other nerves such as the pudendal nerve that follow deep or complex courses. Neurography has also been helpful for improving image diagnosis in spine disorders. It can help identify which spinal nerve is actually irritated as a supplement to routine spinal MRI. Standard spinal MRI only demonstrates the anatomy and numerous disk bulges, bone spurs or stenoses that may or may not actually cause nerve impingement symptoms.

The function of the parasympathetic nervous system is to put the body in a state conducive to rest, regeneration, digestion, and reproduction; the phrase often invoked to describe it is "rest and digest" or "feed and breed". Both of these aforementioned systems use acetylcholine, but in different ways. At a schematic level, the sympathetic and parasympathetic nervous systems are both organized in essentially the same way: preganglionic neurons in the central nervous system send projections to neurons located in autonomic ganglia, which send output projections to virtually every tissue of the body. In both branches the internal connections, the projections from the central nervous system to the autonomic ganglia, use acetylcholine as a neurotransmitter to innervate (or excite) ganglia neurons.

This means that the temporal branch of the facial nerve receives motor input from both hemispheres of the cerebral cortex whereas the zygomatic, buccal, mandibular and cervical branches receive information from only contralateral hemispheres. Now, because the anterior FMN receives only contralateral cortical input whereas the posterior receives that which is bilateral, a corticobulbar lesion (UMN lesion) occurring in the left hemisphere would eliminate motor input to the right anterior FMN component, thus removing signaling to the inferior four facial nerve branches, thereby paralyzing the right mid- and lower-face. The posterior component, however, although now only receiving input from the right hemisphere, is still able to allow the temporal branch to sufficiently innervate the entire forehead. This means that the forehead will not be paralyzed.

She later targeted hyperactivity of peripheral neurons using an agonist for inhibitory neurons and was able to ameliorate ASD-like behaviors in rodent models of ASD. In 2019, Orefice was promoted to Assistant Professor in the Department of Molecular Biology at Massachusetts General Hospital as well as Assistant Professor in the Department of Genetics at Harvard University. She is the principal investigator of the Orefice Lab and her research focuses on understanding the basic biology of the somatosensory circuits that mediate touch and sensations within the gastrointestinal system. She is particularly interested in exploring the development and function of peripheral sensory neurons that innervate internal organs since these might mediate the brain-gut connection to influence behavior and brain-related disease.

Corticotropin-releasing factors travel to the pituitary gland, where they activate the release of adrenocorticotropic hormone (ACTH). The release of the adrenocorticotropic hormone is determined by the release of the corticotropin- releasing factor as the interruption of the corticotropin-releasing factor causes a weakening of the adrenocorticotropic hormone response. Adrenocorticotropic hormones bind to ACTH receptors on the cells within the adrenal medulla and adrenal cortex, causing a signal cascade within the adrenomedullary cell, ultimately releasing the neurotransmitter acetylcholine. The neurotransmitter acetylcholine causes the excitation of the nerves that innervate the skeletal muscles along with the muscles surrounding certain bodily systems such as the cardiovascular system and respiratory system, causing an increase in force production by the skeletal muscles along with accelerated heart rate and breathing rate, respectively.

The LOCS (originating from both the intrinsic and shell neurons) contains unmyelinated fibres that synapse with the dendrites of the Type I spiral ganglion cells projecting to the inner hair cells. While the intrinsic LOCS neurons tend to be small (~10 to 15 µm in diameter), and the shell OC neurons are larger (~25 µm in diameter), it is the intrinsic OC neurons that possess the larger axons (0.77 µm compared to 0.37 µm diameter for shell neurons). In contrast, the MOCS contains myelinated nerve fibres which innervate the outer hair cells directly. Although both the LOCS and MOCS contain crossed (contralateral) and uncrossed (ipsilateral) fibres, in most mammalian species the majority of LOCS fibres project to the ipsilateral cochlea, whilst the majority of the MOCS fibres project to the contralateral cochlea.

Multiunit smooth muscle tissues innervate individual cells; as such, they allow for fine control and gradual responses, much like motor unit recruitment in skeletal muscle. Smooth muscle is found within the walls of blood vessels (such smooth muscle specifically being termed vascular smooth muscle) such as in the tunica media layer of large (aorta) and small arteries, arterioles and veins. Smooth muscle is also found in lymphatic vessels, the urinary bladder, uterus (termed uterine smooth muscle), male and female reproductive tracts, gastrointestinal tract, respiratory tract, arrector pili of skin, the ciliary muscle, and iris of the eye. The structure and function is basically the same in smooth muscle cells in different organs, but the inducing stimuli differ substantially, in order to perform individual effects in the body at individual times.

The anterior corticospinal tract (also called the ventral corticospinal tract, "Bundle of Turck", medial corticospinal tract, direct pyramidal tract, or anterior cerebrospinal fasciculus) is a small bundle of descending fibers that connect the cerebral cortex to the spinal cord. Descending tracts are pathways by which motor signals are sent from upper motor neurons in the brain to lower motor neurons which then directly innervate muscle to produce movement. The anterior corticospinal tract is usually small, varying inversely in size with the lateral corticospinal tract, which is the main part of the corticospinal tract. It lies close to the anterior median fissure, and is present only in the upper part of the spinal cord; gradually diminishing in size as it descends, it ends about the middle of the thoracic region.

George’s published papers show that the large neurons in the spinal cord supplying individual muscles are clustered together in discrete nuclei termed pools that are arranged in register with the position of the limb muscles they are programmed to innervate. Furthermore, in a now-classic paper published in 1951, Romanes showed that the pools of motor neurons innervating the muscles that act together to control a limb joint are themselves grouped together into larger clusters – thus uncovering a remarkable positional registration between a motor neuron and its target muscle. George reasoned that “all the higher parts of the central nervous system would be organized in a similar basic way “, a premise that is now gathering experimental support. His contemporaries used the utility of his maps to identify the pathognomonic lesions of motoneurones seen in the polio epidemic which was sweeping the USA.

In the human brainstem, the solitary nucleus (SN) (nucleus of the solitary tract, nucleus solitarius, nucleus tractus solitarii) is a series of purely sensory nuclei (clusters of nerve cell bodies) forming a vertical column of grey matter embedded in the medulla oblongata. Through the center of the SN runs the solitary tract, a white bundle of nerve fibers, including fibers from the facial, glossopharyngeal and vagus nerves, that innervate the SN. The SN projects to, among other regions, the reticular formation, parasympathetic preganglionic neurons, hypothalamus and thalamus, forming circuits that contribute to autonomic regulation. Cells along the length of the SN are arranged roughly in accordance with function; for instance, cells involved in taste are located In the rostrum part, while those receiving information from cardio-respiratory and gastrointestinal processes are found in the caudal part.

Three common digital nerves (nn. digitales plantares communes) arise from the deep branch of the medial plantar nerve and pass between the divisions of the plantar aponeurosis, each splits into two proper digital nerves—those of the first common digital nerve supply the adjacent sides of the great and second toes; those of the second, the adjacent sides of the second and third toes; and those of the third, the adjacent sides of the third and fourth toes. The third common digital nerve receives a communicating branch from the lateral plantar nerve; that helps innervate the adjacent sides of the third and fourth toes. Each proper digital nerve gives off cutaneous and articular filaments; and opposite the last phalanx sends upward a dorsal branch, which supplies the structures around the nail, the continuation of the nerve being distributed to the ball of the toe.

Like the olfactory system, the taste system is defined by its specialized peripheral receptors and central pathways that relay and process taste information. Peripheral taste receptors are found on the upper surface of the tongue, soft palate, pharynx, and the upper part of the esophagus. Taste cells synapse with primary sensory axons that run in the chorda tympani and greater superficial petrosal branches of the facial nerve (cranial nerve VII), the lingual branch of the glossopharyngeal nerve (cranial nerve IX), and the superior laryngeal branch of the vagus nerve (Cranial nerve X) to innervate the taste buds in the tongue, palate, epiglottis, and esophagus respectively. The central axons of these primary sensory neurons in the respective cranial nerve ganglia project to rostral and lateral regions of the nucleus of the solitary tract in the medulla, which is also known as the gustatory nucleus of the solitary tract complex.

A lesion on either the left or right side would affect both the anterior and posterior routes on that side because of their close physical proximity to one another. So, a lesion on the left side would inhibit muscle innervation from both the left posterior and anterior routes, thus paralyzing the whole left side of the face (Bell’s palsy). With this type of lesion, the bilateral and contralateral inputs of the posterior and anterior routes, respectively, become irrelevant because the lesion is below the level of the medulla and the facial motor nucleus. Whereas at a level above the medulla a lesion occurring in one hemisphere would mean that the other hemisphere could still sufficiently innervate the posterior facial motor nucleus, a lesion affecting a lower motor neuron would eliminate innervation altogether because the nerves no longer have a means to receive compensatory contralateral input at a downstream decussation.

Schematic representation of the Flip-Flop Switch Hypothesis In the early 20th century, Constantin von Economo noted that humans who had encephalitis with lesions in the anterior hypothalamus had insomnia, and proposed a sleep-promoting influence from that area. Animal studies in the mid-20th century in rats and cats confirmed that very large lesions in the preoptic area and basal forebrain resulted in insomnia but did not identify the cell group that was responsible. In 1996, Sherin and colleagues reported the presence of a cell group in the VLPO that expresses cFos (a protein often found in neurons that have recently been active) during sleep, and that these neurons contain the inhibitory neurotransmitters GABA and galanin. . These same neurons were found to innervate components of the ascending arousal system, including the tuberomammillary nucleus (TMN) and other components of the lateral hypothalamus; the raphe nuclei; the locus coeruleus (LC); the pedunculopontine (PPT) and laterodorsal tegmental nuclei (LDT); and the parabrachial nucleus (PB).

The pre-locus coeruleus was first formally defined during the course of neuroanatomical tract-tracing and c-Fos experiments aimed at uncovering the connections and functions of aldosterone-sensitive HSD2 neurons in the nucleus of the solitary tract. First, HSD2 neurons were found to innervate the pre-LC, as evidenced by (1) dense labeling with an anterograde axonal tracer in pre-LC after that tracer had been injected into the nucleus of the solitary tract and (2) the complementary finding of retrograde labeling of HSD2 neurons after injection of a retrograde tracer into the pre-LC. Further, experimental conditions which activate the HSD2 neurons simultaneously activate a cluster of neurons in pre-LC, in the same location as axon terminals labeled with an anterograde tracer from the NTS. Based on these observations, the pre-locus coeruleus ("pre-LC") was defined as the cluster of neurons which: #are found in a specific location rostral to the LC (see "Location," below), #receive axonal input from HSD2 neurons in the NTS, and #become c-Fos positive during dietary sodium deprivation.

Breaking the humerus and deep puncture wounds can also cause the condition. Posterior interosseus palsy is distinguished from radial nerve palsy by the preservation of elbow extension. Symptoms vary depending on the severity and location of the trauma; however, common symptoms include wrist drop (the inability to extend the wrist upward when the hand is palm down); numbness of the back of the hand and wrist, specifically over the first web space which is innervated by the radial nerve; and inability to voluntarily straighten the fingers or extend the thumb, which is performed by muscles of the extensor group, all of which are primarily innervated by the radial nerve. Loss of wrist extension is due to paralysis of the posterior compartment of forearm muscles; although the elbow extensors are also innervated by the radial nerve, their innervation is usually spared because the compression occurs below, distal, to the level of the axillary nerve, which innervates the long head of the triceps, and the upper branches of the radial nerve that innervate the remainder of the Triceps.. Saturnine neuropathy can also be a cause of radial neuropathy (radial palsy).