Then the bullfighter's assistant slices the medulla oblongata to slowly halt respiratory and cardiac functions.
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My iPhone may as well be lodged in my brainstem, right between the pons and medulla oblongata.
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" Featuring a row of gentle song stylists cupping their own brains in their hands, this one contains the classic tender line, "I used to love a-lotta your Medulla Oblongata.
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The scan showed something unusual: a large "infiltrating" lesion centered in the medulla oblongata, the structure at the lower end of the brainstem that controls breathing and other involuntary functions.
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The posterior median sulcus of medulla oblongata (or posterior median fissure or dorsal median sulcus) is a narrow groove; and exists only in the closed part of the medulla oblongata; it becomes gradually shallower from below upward, and finally ends about the middle of the medulla oblongata, where the central canal expands into the cavity of the fourth ventricle.
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In some judicial hangings, the odontoid process may break and hit the medulla oblongata, causing death.
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The parts of the brainstem are the midbrain, the pons, and the medulla oblongata, and sometimes the diencephalon.
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The myelencephalon or afterbrain is the most posterior region of the embryonic hindbrain, from which the medulla oblongata develops.
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Cell group B1 occupies the midline nucleus raphes pallidus and adjacent structures in the caudal medulla oblongata of the rodent and the primate.
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Cell group B2 occupies the midline nucleus raphes obscurus and adjacent structures in the caudal medulla oblongata of the rodent and the primate.
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During embryonic development the medulla oblongata develops from the myelencephalon. The myelencephalon is a secondary vesicle which forms during the maturation of the rhombencephalon, also referred to as the hindbrain. The bulb is an archaic term for the medulla oblongata and in modern clinical usage the word bulbar (as in bulbar palsy) is retained for terms that relate to the medulla oblongata, particularly in reference to medical conditions. The word bulbar can refer to the nerves and tracts connected to the medulla, and also by association to those muscles innervated, such as those of the tongue, pharynx and larynx.
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Because of its location in the brainstem and its many important roles in the autonomic nervous system, damage to the medulla oblongata is usually fatal.
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The ventral portion of the medulla oblongata contains the medullary pyramids. These two ridge-like structures travel along the length of the medulla oblongata and are bordered medially by the anterior median fissure. They each have an anterolateral sulcus along their lateral borders, where the hypoglossal nerve emerges from. Also at the side of each pyramid there is a pronounced bulge known as an olive.
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Frogs have a highly developed nervous system that consists of a brain, spinal cord and nerves. Many parts of frog brains correspond with those of humans. It consists of two olfactory lobes, two cerebral hemispheres, a pineal body, two optic lobes, a cerebellum and a medulla oblongata. Muscular coordination and posture are controlled by the cerebellum, and the medulla oblongata regulates respiration, digestion and other automatic functions.
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Its action at the chemoreceptor trigger zone (in the area postrema) and the solitary nucleus (in the medulla oblongata) allow it to have an antiemetic effect.
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The other 10% of the fibers stay uncrossed in the anterior corticospinal tract. The pyramidal decussation marks the border between the spinal cord and the medulla oblongata.
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Trimethobenzamide is an antagonist of the D2 receptor. It is believed to affect the chemoreceptor trigger zone (CTZ) of the medulla oblongata to suppress nausea and vomiting.
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Babinski–Nageotte syndrome is an alternating brainstem syndrome. It occurs when there is damage to the dorsolateral or posterior lateral medulla oblongata, likely syphilitic in origin. Hence it is also called the alternating medulla oblongata syndrome. The rare disorder is caused by damage to a part of the brain (medullobulbar transitional area) which causes a variety of neurological symptoms, some of which affect only one side of the body.
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Fibers of the posterior column, which transmit sensory and proprioceptive information, are located behind the pyramids on the medulla oblongata. The medullary pyramids contain motor fibers that are known as the corticobulbar and corticospinal tracts. The corticospinal tracts are on the anterior surface of the pyramids. These tracts transport motor signals that originated in the precentral gyrus and travelled through the internal capsule to the medulla oblongata and pyramids.
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The motor division of the vagus nerve is derived from the basal plate of the embryonic medulla oblongata, while the sensory division originates from the cranial neural crest.
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Middle cerebellar peduncle is located inferior and lateral to the superior cerebellar peduncle, connecting pons to the cerebellum. Likewise, inferior cerebellar peduncle is found connecting the medulla oblongata to the cerebellum.
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Cell group B3 occupies the midline nucleus raphes magnus and adjacent structures in the caudal medulla oblongata of the rodent and the primate. Its boundary with the serotonergic group B1 is indistinct.
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The anterolateral sulcus (or ventrolateral sulcus) is a sulcus on the side of the medulla oblongata between the olive and pyramid. The rootlets of the hypoglossal nerve (CN XII) emerge from this sulcus.
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The anterior layer is continuous inferiorly with the pia mater on the inferior cerebellar peduncles and the closed part of the medulla oblongata. The posterior layer covers the antero-inferior surface of the cerebellum.
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The cough center is a region of the brain which controls coughing. The cough center is located in the medulla oblongata in the brainstem. Cough suppressants focus their action on the cough center.D.C. Bolser.
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It is caused by damage to the medulla oblongata due to strokes or trauma. It generally indicates a poor prognosis, and usually progresses to complete apnea. The term is sometimes used interchangeably with Biot's Respirations.
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The two pyramids contain the motor fibers that pass from the brain to the medulla oblongata and spinal cord. These are the corticobulbar and corticospinal fibers that make up the pyramidal tracts. About 90% of these fibers leave the pyramids in successive bundles and decussate (cross over) in the anterior median fissure of the medulla oblongata as the pyramidal decussation or motor decussation. Having crossed over at the middle line, they pass down in the posterior part of the lateral funiculus as the lateral corticospinal tract.
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The upper part of the posterior district of the medulla oblongata is occupied by the inferior cerebellar peduncle, a thick rope-like strand situated between the lower part of the fourth ventricle and the roots of the glossopharyngeal and vagus nerves. Each cerebellar inferior peduncle connects the spinal cord and medulla oblongata with the cerebellum, and comprises the juxtarestiform body and restiform body. Important fibers running through the inferior cerebellar peduncle include the dorsal spinocerebellar tract and axons from the inferior olivary nucleus, among others.
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Whiplash as a result of a car accident can lead to brainstem injuries that affect the pyramids at the medulla oblongata. These pyramid injuries are usually a result of a dislocation at the occiput or spinal level C1. Injuries to the pyramids of the medulla oblongata can also be caused by the quick hyperextension of the neck (cervical region of the spine). Hyperextension of the neck can pull and tear the pyramids, leading to a variety of symptoms such as weakness in all four limbs, difficulty swallowing, and difficulty speaking.
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The diencephalon gives rise to the thalamus and hypothalamus. The hindbrain also splits into two areas – the metencephalon and the myelencephalon. The metencephalon gives rise to the cerebellum and pons. The myelencephalon gives rise to the medulla oblongata.
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He described a finger flexion reflex called the Bekhterev- Jacobsohn reflex or Jacobsohn reflex. In 1909 he first described the pedunculopontine nucleus.Über die Kerne des menschlichen Hirnstamms (Medulla oblongata, Pons und Pedunculus cerebri), Berlin, 1909. pag. 58, fig.
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In anatomy, the olivary bodies or simply olives (Latin oliva and olivae, singular and plural, respectively) are a pair of prominent oval structures in the medulla oblongata, the lower portion of the brainstem. They contain the olivary nuclei.
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Medulla Oblongata is a 2014 Indian Malayalam-language film produced by S. Madhan and directed by Suresh Nair. It is the remake of 2012 Tamil film Naduvula Konjam Pakkatha Kaanom. The remake stars Rahul Madhav and newcomer Aavaana.
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The myenteric plexus originates in the medulla oblongata as a collection of neurons from the ventral part of the brain stem. The vagus nerve then carries the axons to their destination in the gastrointestinal tract. They contain Dogiel cells.
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The specific name refers to the medulla oblongata, the brain part encased by the partial braincase.Kurzanov, S. M. (1976) Braincase structure in the carnosaur Itemirus n. gen. and some aspects of the cranial anatomy of dinosaurs. Paleontological Journal 10:361-369.
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The pons regulates breathing through particular nuclei that regulate the breathing center of the medulla oblongata. The cerebellum works to coordinate muscle movements, maintain posture, and integrate sensory information from the inner ear and proprioceptors in the muscles and joints.
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The anterior median fissure (ventral or ventromedian fissure) contains a fold of pia mater, and extends along the entire length of the medulla oblongata: It ends at the lower border of the pons in a small triangular expansion, termed the foramen cecum. Its lower part is interrupted by bundles of fibers that cross obliquely from one side to the other, and constitute the pyramidal decussation. Some fibers, termed the anterior external arcuate fibers, emerge from the fissure above this decussation and curve lateralward and upward over the surface of the medulla oblongata to join the inferior peduncle.
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The pontine flexure, also called the rhombic flexure, forms the boundary between the metencephalon and the myelencephalon. The metencephalon becomes the pons and the cerebellum, and the myelencephalon becomes the medulla oblongata. These two regions develop and fold dorsally at the pontine flexure.
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The medullary pyramids are paired white matter structures of the brainstem's medulla oblongata that contain motor fibers of the corticospinal and corticobulbar tracts – known together as the pyramidal tracts. The lower limit of the pyramids is marked when the fibers cross (decussate).
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The inferior olivary nucleus (ION), is a structure found in the medulla oblongata underneath the superior olivary nucleus.Gado, Thomas A. Woolsey; Joseph Hanaway; Mokhtar H. (2003). The brain atlas a visual guide to the human central nervous system (2nd ed.). Hoboken, NJ: Wiley. p. 206. .
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The cerebrospinal fibers, derived from the cells of the motor area of the cerebral cortex, occupy the middle three-fifths of the base; they are continued partly to the nuclei of the motor cranial nerves, but mainly into the pyramids of the medulla oblongata.
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It transmits the hypoglossal nerve from its point of entry near the medulla oblongata to its exit from the base of the skull near the jugular foramen. It lies in the epiphyseal junction between the basiocciput and the jugular process of the occipital bone.
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It is located within the pons or in the upper part of the medulla oblongata. CSF entering the fourth ventricle through the cerebral aqueduct can exit to the subarachnoid space of the spinal cord through two lateral apertures and a single, midline median aperture.
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The brainstem includes the midbrain, the pons, and the medulla oblongata. Behind the brainstem is the cerebellum (). The cerebrum, brainstem, cerebellum, and spinal cord are covered by three membranes called meninges. The membranes are the tough dura mater; the middle arachnoid mater and the more delicate inner pia mater.
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On wakefulness, this constitutes an error signal which provokes hyperventilation until the wakefulness set point is reached. When the subject falls asleep, ventilation decreases and pCO2 rises, resulting in hypoventilation or even apnea. These oscillations continue until steady state sleep is obtained. The medulla oblongata controls our respiration.
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Bulbar palsy refers to a range of different signs and symptoms linked to impairment of function of the cranial nerves IX, X, XI, XII, which occurs due to a lower motor neuron lesion in the medulla oblongata or from lesions of the lower cranial nerves outside the brainstem.
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Death may result from several pathologies that deviate from benign laughter. Infarction of the pons and medulla oblongata in the brain may cause pathological laughter. Laughter can cause atonia and collapse ("agelastic syncope"), which in turn can cause trauma. See also laughter-induced syncope, cataplexy, and Bezold-Jarisch reflex.
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Involuntary respiration is controlled by respiratory centers within the medulla oblongata and pons. The medullary respiratory center can be subdivided into anterior and posterior portions. They are called the ventral and dorsal respiratory groups respectively. The pontine respiratory group consists of two parts: the pneumotaxic center and the apneustic center.
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The motor neuron is present in the grey matter of the spinal cord and medulla oblongata, and forms an electrochemical pathway to the effector organ or muscle. Besides motor nerves, there are efferent sensory nerves that often serve to adjust the sensitivity of the signal relayed by the afferent sensory nerve.
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Medial medullary syndrome, also known as inferior alternating syndrome, hypoglossal alternating hemiplegia, lower alternating hemiplegia, or Dejerine syndrome, is a type of alternating hemiplegia characterized by a set of clinical features resulting from occlusion of the anterior spinal artery. This results in the infarction of medial part of the medulla oblongata.
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The cardiovascular centre is a part of the human brain which regulates heart rate through the nervous and endocrine systems. It is found in the medulla oblongata. Normally, the heart beats without nervous control, but in some situations (e.g., exercise, body trauma), the cardiovascular centre is responsible for altering the heart rate.
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PET117 homolog is a protein that in humans is encoded by the PET117 gene. Localized to mitochondria, this protein is a chaperone protein involved in the assembly of mitochondrial Complex IV, or Cytochrome C Oxidase. Mutations in this gene can cause Complex IV deficiency with symptoms including medulla oblongata lesions and lactic acidosis.
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The pontine tegmentum, or dorsal pons, is located within the brainstem, and is one of two parts of the pons, the other being the ventral pons or basilar part of the pons. The pontine tegmentum can be defined in contrast to the basilar pons: basilar pons contains the corticospinal tract running craniocaudally and can be considered the rostral extension of the ventral medulla oblongata; however, basilar pons is distinguished from ventral medulla oblongata in that it contains additional transverse pontine fibres that continue laterally to become the middle cerebellar peduncle. The pontine tegmentum is all the material dorsal from the basilar pons to the fourth ventricle. Along with the dorsal surface of the medulla, it forms part of the rhomboid fossa – the floor of the fourth ventricle.
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Elongation of the cerebellar tonsils can, due to pressure, lead to this portion of the cerebellum to slip or be pushed through the foramen magnum of the skull resulting in tonsillar herniation. This is a life-threatening condition as it causes increased pressure on the medulla oblongata which contains respiratory and cardiac control centres.
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The feedback from the carotid body is sent to the cardiorespiratory centers in the medulla oblongata via the afferent branches of the glossopharyngeal nerve. The efferent fibres of the aortic body chemoreceptors are relayed by the vagus nerve. These centers, in turn, regulate breathing and blood pressure, with hypoxia causing an increase in ventilation.
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Preganglionic sympathetic neurons are located in the spinal cord, at the thorax and upper lumbar levels. Preganglionic parasympathetic neurons are found in the medulla oblongata where they form visceral motor nuclei; the dorsal motor nucleus of the vagus nerve; the nucleus ambiguus, the salivatory nuclei, and in the sacral region of the spinal cord.
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The medulla oblongata, located between pons and spine, seems to have the capacity for organism-wide muscle inhibition.Yuan- Yang Lai & Jerome M. Siegel (1999), "Muscle Atonia in REM Sleep", in Rapid Eye Movement Sleep ed. Mallick & Inoué. Some localized twitching and reflexes can still occur.Parmeggiani (2011), Systemic Homeostasis and Poikilostasis in Sleep, p. 17.
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In the upper part of the medulla oblongata, the hypoglossal nucleus approaches the rhomboid fossa, where it lies close to the middle line, under an eminence named the hypoglossal trigone. It is a slight elevation in the floor of the inferior recess of the fourth ventricle, beneath which is the nucleus of origin of the twelfth cranial nerve.
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Yellow represents full neocortex engagement and Stage 6. The disease begins in structures of the lower brainstem and the olfactory system. In particular, the dorsal motor nucleus of the vagus nerve in the medulla oblongata and anterior olfactory nucleus are affected. Lewy neurites, thread- like alpha-synuclein aggregates, are more prevalent than globular Lewy bodies in this stage.
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In addition to the pathology observed in Stage 1, Stage 2 is characterized by additional lesions in the raphe nuclei and gigantocellular reticular nucleus of the medulla oblongata. The disease then moves up the brainstem, traveling from the medullary structures to the locus ceruleus in the pontine tegmentum. Similar to Stage 1, Lewy neurites outnumber Lewy bodies.
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He worked as secondary physician at the Allgemeines Krankenhaus in Vienna, and in 1879 became habilitated for internal medicine. Weiss is remembered for pioneer systematic research of the spinal marrow, medulla oblongata and basal ganglia. The eponymous "Weiss' sign" is named after him, which today is usually referred to as "Chvostek's sign".Weiss N. Centralbl Gesammt Ther 1883;1:9.
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Different phases of digestion take place including: the cephalic phase, gastric phase, and intestinal phase. The cephalic phase occurs at the sight, thought and smell of food, which stimulate the cerebral cortex. Taste and smell stimuli are sent to the hypothalamus and medulla oblongata. After this it is routed through the vagus nerve and release of acetylcholine.
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Autonomic innervation of the heart The heart receives nerve signals from the vagus nerve and from nerves arising from the sympathetic trunk. These nerves act to influence, but not control, the heart rate. Sympathetic nerves also influence the force of heart contraction. Signals that travel along these nerves arise from two paired cardiovascular centres in the medulla oblongata.
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Some neurons terminate in the spinal cord, where they contribute to a reflex response. Other neurons continue ipsilaterally, same side, to the medulla oblongata. If the neurons are coming from the lower limbs, they are carried by the fasciculus gracilis into the medulla. If the neurons are coming from the upper limbs; they are carried by the fasciculus cuneatus.
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The breathing rate increases when the partial pressure of carbon dioxide in the blood increases. This is detected by central blood gas chemoreceptors on the anterior surface of the medulla oblongata. The aortic and carotid bodies, are the peripheral blood gas chemoreceptors which are particularly sensitive to the arterial partial pressure of O2 though they also respond, but less strongly, to the partial pressure of CO2. At sea level, under normal circumstances, the breathing rate and depth, is determined primarily by the arterial partial pressure of carbon dioxide rather than by the arterial partial pressure of oxygen, which is allowed to vary within a fairly wide range before the respiratory centers in the medulla oblongata and pons respond to it to change the rate and depth of breathing.
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For instance, the arterial blood pressure in mammals is homeostatically controlled, and measured by stretch receptors in the walls of the aortic arch and carotid sinuses at beginnings of the internal carotid arteries. The sensors send messages via sensory nerves to the medulla oblongata of the brain indicating whether the blood pressure has fallen or risen, and by how much. The medulla oblongata then distributes messages along motor or efferent nerves belonging to the autonomic nervous system to a wide variety of effector organs, whose activity is consequently changed to reverse the error in the blood pressure. One of the effector organs is the heart whose rate is stimulated to rise (tachycardia) when the arterial blood pressure falls, or to slow down (bradycardia) when the pressure rises above set point.
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The pathogenesis of scrapie involves the lymphatic system. Once the agent is absorbed through the intestines, misfolded prions first appear and accumulate in the lymph nodes, especially in Peyer's patches at the small intestine.Tarmen viktig for skrapesyke - forskning.no Eventually, the infection invades the brain, often through the spinal cord or the medulla oblongata by creeping up the sympathetic and parasympathetic nervous system, respectively.
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Researchers have tried to develop methods to measure PrPSc, but no methods for use in materials such as blood have been accepted fully. The traditional method of diagnosis relies on histopathological examination of the medulla oblongata of the brain, and other tissues, post mortem. Immunohistochemistry can be used to demonstrate prion protein accumulation.Bovine Spongiform Encephalopathy reviewed and published by WikiVet.
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The diencephalon, mesencephalon and rhombencephalon constitute the brain stem of the embryo. It continues to flex at the mesencephalon. The rhombencephalon folds posteriorly, which causes its alar plate to flare and form the fourth ventricle of the brain. The pons and the cerebellum form in the upper part of the rhombencephalon, whilst the medulla oblongata forms in the lower part.
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Damage to the defecation centre within the medulla oblongata of the brain can lead to bowel dysfunction. A stroke or acquired brain injury may lead to damage to this centre in the brain. Damage to the defecation centre can lead to a loss of coordination between rectal and anal contractions and also a loss of awareness of the need to defecate.
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The hypoglossal nucleus bulges into the floor, creating the hypoglossal trigone, located slightly superiorly to the inferior fovea, within the median eminance. The dorsal nucleus of vagus nerve, within the medulla oblongata, comprises cells that are spindle shaped, also creating a bulge—the vagal trigone—in the region of the floor which overlies them; this is the region inferior of the inferior fovea.
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In the following year he read before the Royal Society a paper On the Inverse Ratio which Subsists between Respiration and Irritability in the Animal Kingdom. His most important work in physiology was concerned with the theory of reflex action, embodied in a paper On the Reflex Function of the Medulla Oblongata and the Medulla Spinalis (1833)Hall M. On the reflex function of the medulla oblongata and medulla spinalis. Philosophical Transactions 1833, 123: 635–665, which was supplemented in 1837 by another On the True Spinal Marrow, and the Excito-motor System of Nerves. In this theory, he stated that the spinal cord is comprised by a chain of units that functions as an independent reflex arcs, and their activity integrates sensory and motor nerves at the segment of the spinal cord from which these nerves originate.
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The anterior median fissure contains a fold of pia mater, and extends along the length of the medulla oblongata. It ends at the lower border of the pons in a small triangular area, termed the foramen cecum. On either side of this fissure are raised areas termed the medullary pyramids. The pyramids house the pyramidal tracts–the corticospinal and the corticobulbar tracts of the nervous system.
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Autonomic innervation of the heart The wave of depolarization in a normal sinus rhythm shows a stable resting HR. Following parasympathetic stimulation, HR slows. Following sympathetic stimulation, HR increases. The normal sinus rhythm of the heart rate is generated by the SA node. It is also influenced by central factors through sympathetic and parasympathetic nerves of the two paired cardiovascular centres of the medulla oblongata.
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It is made up of a lateral and anterior tract. The corticospinal tract is involved in voluntary movement. The majority of fibres of the corticospinal tract cross over in the medulla oblongata, resulting in muscles being controlled by the opposite side of the brain. The corticospinal tract contains the axons of the pyramidal cells, the largest of which are the Betz cells, located in the cerebral cortex.
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This generally occurs in the anterior grey column. Nerve axons of the lateral corticospinal tract that did not cross over in the medulla oblongata do so at the level of the spinal cord they terminate in. These tracts contain more than 1 million axons and the majority of the axons are myelinated. The corticospinal tracts myelinate largely during the first and second years after birth.
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The corticobulbar (or corticonuclear) tract is a two-neuron white matter motor pathway connecting the motor cortex in the cerebral cortex to the medullary pyramids, which are part of the brainstem's medulla oblongata (also called "bulbar") region, and are primarily involved in carrying the motor function of the non-oculomotor cranial nerves. The corticobulbar tract is one of the pyramidal tracts, the other being the corticospinal tract.
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Lateral medullary syndrome is a neurological disorder causing a range of symptoms due to ischemia in the lateral part of the medulla oblongata in the brainstem. The ischemia is a result of a blockage most commonly in the vertebral artery or the posterior inferior cerebellar artery. Lateral medullary syndrome is also called Wallenberg's syndrome, posterior inferior cerebellar artery (PICA) syndrome and vertebral artery syndrome.
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The three major arteries of the cerebellum: the SCA, AICA, and PICA. (Posterior inferior cerebellar artery is PICA.) Human brainstem blood supply description. PICA is #12. It is the clinical manifestation resulting from occlusion of the posterior inferior cerebellar artery (PICA) or one of its branches or of the vertebral artery, in which the lateral part of the medulla oblongata infarcts, resulting in a typical pattern.
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England In the same year, Luigi Galvani described the role of electricity in nerves of dissected frogs. In 1808, Franz Joseph Gall studied and published work on phrenology. Phrenology was the faulty science of looking at head shape to determine different aspects of personality and brain function. In 1811, studied respiration in animal dissection and lesions and found the center of respiration in the medulla oblongata.
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It opens chemical or ligand-gated sodium and calcium ion channels, allowing an influx of positively charged ions. Norepinephrine binds to the beta–1 receptor. High blood pressure medications are used to block these receptors and so reduce the heart rate. Autonomic Innervation of the Heart - Cardioaccelerator and cardioinhibitory areas are components of the paired cardiac centers located in the medulla oblongata of the brain.
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The only reported mutation in the PET117 gene was a homozygous nonsense mutation (c. 172 C>T) in two sister patients. Both were diagnosed with Complex IV deficiency and had lesions in their medulla oblongata, along with lactic acidosis. Symptoms in the older sister included abnormal motor development, regression in speech and motor skills after age ten, bradykinesia, hypokinesia, and pyramidal signs with positive Babinski response.
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RAI14 is expressed within a wide range of human tissues. Some areas of the highest expression by TPM (transcripts per million) include tissues of the endometrium, smooth muscle, cervix, cervix, testis, and spleen. Within the human brain, RAI14 expression is abundant in the area around the brain stem and medulla. The highest expression levels came from the myelencephalon, a region of the embryonic brain that would later become the medulla oblongata.
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Dolasetron (trade name Anzemet) is a serotonin 5-HT3 receptor antagonist used to treat nausea and vomiting following chemotherapy. Its main effect is to reduce the activity of the vagus nerve, which is a nerve that activates the vomiting center in the medulla oblongata. It does not have much antiemetic effect when symptoms are due to motion sickness. This drug does not have any effect on dopamine receptors or muscarinic receptors.
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Pre-pro U-II in both humans and rats are primarily expressed in the motorneurons of the brainstem and spinal cord although it is also found in small amounts in other parts of the brain as well including the frontal lobe and the medulla oblongata. In humans U-II mRNA is also found in other peripheral tissues such as the heart, kidneys, adrenal gland, placenta, spleen, and thymus.
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Both lampreys and hagfish possess a fully developed medulla oblongata. Since these are both very similar to early agnathans, it has been suggested that the medulla evolved in these early fish, approximately 505 million years ago.Haycock, Being and Perceiving The status of the medulla as part of the primordial reptilian brain is confirmed by its disproportionate size in modern reptiles such as the crocodile, alligator, and monitor lizard.
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Granisetron is a serotonin 5-HT3 receptor antagonist used as an antiemetic to treat nausea and vomiting following chemotherapy and radiotherapy. Its main effect is to reduce the activity of the vagus nerve, which is a nerve that activates the vomiting center in the medulla oblongata. It does not have much effect on vomiting due to motion sickness. This drug does not have any effect on dopamine receptors or muscarinic receptors.
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Although the left and right hemispheres are broadly similar in shape and function, some functions are associated with one side, such as language in the left and visual-spatial ability in the right. The hemispheres are connected by commissural nerve tracts, the largest being the corpus callosum. The cerebrum is connected by the brainstem to the spinal cord. The brainstem consists of the midbrain, the pons, and the medulla oblongata.
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CB1 receptors are found primarily in the brain, more specifically in the basal ganglia and in the limbic system, including the hippocampus and the striatum. They are also found in the cerebellum and in both male and female reproductive systems. CB1 receptors are absent in the medulla oblongata, the part of the brain stem responsible for respiratory and cardiovascular functions. CB1 is also found in the human anterior eye and retina.
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It measures changes in blood pressure and the composition of arterial blood flowing past it, including the partial pressures of oxygen and carbon dioxide. The chemoreceptors responsible for sensing changes in blood gases are called glomus cells. It gives feedback to the medulla oblongata, specifically to the dorsal respiratory group, via the afferent branches of the vagus nerve (X). The medulla, in turn, regulates breathing and blood pressure.
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The anterior spinal artery arises bilaterally as two small branches near the termination of the vertebral arteries. One of these vessels is usually larger than the other, but occasionally they are about equal in size. Descending in front of the medulla oblongata, they unite at the level of the foramen magnum. The single trunk descends in the front of the medulla spinalis, extending to the lowest part of the medulla spinalis.
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The respiratory center is located in the medulla oblongata and pons, in the brainstem. The respiratory center is made up of three major respiratory groups of neurons, two in the medulla and one in the pons. In the medulla they are the dorsal respiratory group, and the ventral respiratory group. In the pons, the pontine respiratory group includes two areas known as the pneumotaxic centre and the apneustic centre.
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Adrenaline, also known as epinephrine, is a hormone and medication. Adrenaline is normally produced by both the adrenal glands and a small number of neurons in the medulla oblongata, where it acts as a neurotransmitter involved in regulating visceral functions (e.g., respiration). It plays an important role in the fight-or-flight response by increasing blood flow to muscles, output of the heart, pupil dilation response and blood sugar level.
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On the superior surface of cerebellum, the vermis protrudes above the level of the hemispheres, but on the inferior surface it is sunk almost out of sight in the bottom of a deep depression between them; this depression is called the vallecula of the cerebellum, and lodges the posterior part of the medulla oblongata and the inferior vermis, which consists of the tuber vermis, pyramid, uvula and nodule.
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The Purkinje cells of the cerebellar cortex project into the deep cerebellar nuclei and inhibit the excitatory output system via GABAergic synapses. The fastigial nucleus receives its input from Purkinje cells in the vermis. Most of its efferent connections travel via the inferior cerebellar peduncle to the vestibular nuclei, which are located at the junction of the pons and the medulla oblongata. The fastigial nucleus sends excitatory projections beyond the cerebellum.
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The heart rate is rhythmically generated by the sinoatrial node. It is also influenced by central factors through sympathetic and parasympathetic nerves. Nervous influence over the heart rate is centralized within the two paired cardiovascular centres of the medulla oblongata. The cardioaccelerator regions stimulate activity via sympathetic stimulation of the cardioaccelerator nerves, and the cardioinhibitory centers decrease heart activity via parasympathetic stimulation as one component of the vagus nerve.
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In 1944 Paul Wilcox described triggering of epileptic seizure by electrical stimulation of another area of the cerebral cortex. The chemoreceptor trigger zone is an area of the medulla oblongata in which many types of chemical stimulation can provoke nausea and vomiting. This area was first identified and named in 1951 by Herbert L. Borison and Kenneth R. Brizzee. Parts of cells, rather than parts of the body, can also behave as trigger zones.
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The cisterna magna (or cerebellomedullaris cistern) is one of three principal openings in the subarachnoid space between the arachnoid and pia mater layers of the meninges surrounding the brain. The openings are collectively referred to as the subarachnoid cisterns. The cisterna magna is located between the cerebellum and the dorsal surface of the medulla oblongata. Cerebrospinal fluid produced in the fourth ventricle drains into the cisterna magna via the lateral apertures and median aperture.
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As stated previously, FFA1 has an affinity for long chain fatty acids. Such fatty acids are also present in the brain, where FFA1 has also been found in high abundance. FFA1 receptors are present over the entire brain, but in highest numbers in the medulla oblongata and the substantia nigra. Recent studies have also observed that FFA1 was present in the olfactory bulb, striatum, hippocampus, midbrain, hypothalamus, cerebellum, cerebral cortex and in the spinal cord.
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The diencephalon is the region of the embryonic vertebrate neural tube that gives rise to anterior forebrain structures including the thalamus, hypothalamus, posterior portion of the pituitary gland, and the pineal gland. The diencephalon encloses a cavity called the third ventricle. The thalamus serves as a relay centre for sensory and motor impulses between the spinal cord and medulla oblongata, and the cerebrum. It recognizes sensory impulses of heat, cold, pain, pressure etc.
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Vallecula is an anatomic term for a crevice, depression, or furrow in something. Vallecula at eMedicine Dictionary There are a variety of valleculae in the human body, including one between the hemispheres of the brain, on the inferior surface of the cerebellum, in which the medulla oblongata is located (vallecula of cerebellum). Other common valleculae are: in the nail matrix, and in the throat. Used alone, the term "vallecula" usually refers to the epiglottic vallecula.
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PYY is found in L cells in the mucosa of gastrointestinal tract, especially in ileum and colon. Also, a small amount of PYY, about 1-10%, is found in the esophagus, stomach, duodenum and jejunum. PYY concentration in the circulation increases postprandially (after food ingestion) and decreases by fasting. In addition, PYY is produced by a discrete population of neurons in the brainstem, specifically localized to the gigantocellular reticular nucleus of the medulla oblongata.
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Sometimes, these two naming conventions coexist. For example, the name "pyramidal tract" has been mainly supplanted by lateral corticospinal tract in most texts. Note that the "old" name was primarily descriptive, evoking the pyramids of antiquity, from the appearance of this neural pathway in the medulla oblongata. The "new" name is based primarily on its origin (in the primary motor cortex, Brodmann area 4) and termination (onto the alpha motor neurons of the spinal cord).
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Three principle subarachnoid cisternae consisting of the pons, medulla oblongata, and the cerebellum. A cross-section diagram of the area of the brain typically affected by tumors in the condition CNH. Symptoms of CNH have been observed to vary according to the progression of CNH. The initial symptoms of CNH include a low arterial partial pressure of carbon dioxide, a high or normal arterial partial pressure of oxygen, high arterial pH, and tachypnea.
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Moxonidine is a selective agonist at the imidazoline receptor subtype 1 (I1). This receptor subtype is found in both the rostral ventro-lateral pressor and ventromedial depressor areas of the medulla oblongata. Moxonidine therefore causes a decrease in sympathetic nervous system activity and, therefore, a decrease in blood pressure. Compared to the older central-acting antihypertensives, moxonidine binds with much greater affinity to the imidazoline I1-receptor than to the α2-receptor.
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The glossopharyngeal nerve, known as the ninth cranial nerve (CN IX), is a mixed nerve that carries afferent sensory and efferent motor information. It exits the brainstem out from the sides of the upper medulla, just anterior (closer to the nose) to the vagus nerve. The motor division of the glossopharyngeal nerve is derived from the basal plate of the embryonic medulla oblongata, while the sensory division originates from the cranial neural crest.
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The medulla oblongata or simply medulla is a long stem-like structure which makes up part of the brainstem. It is anterior and partially inferior to the cerebellum. It is a cone-shaped neuronal mass responsible for autonomic (involuntary) functions ranging from vomiting to sneezing. The medulla contains the cardiac, respiratory, vomiting and vasomotor centers and therefore deals with the autonomic functions of breathing, heart rate and blood pressure as well as the sleep wake cycle.
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The pontine nuclei (or griseum pontis) are the nuclei of the pons involved in motor activity. The pontine nuclei are located in the ventral pons. Corticopontine fibres carry information from the primary motor cortex to the ipsilateral pontine nucleus in the ventral pons, and the pontocerebellar projection then carries that information to the contralateral cerebellum via the middle cerebellar peduncle. Extension of these nuclei in the medulla oblongata are named arcuate nucleus (medulla) which has the same function.
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Historically, there have been a variety of terms used for the disorder, including pseudobulbar affect, pathological laughter and crying, emotional lability, emotionalism, emotional dysregulation, or more recently, involuntary emotional expression disorder. The term pseudobulbar (pseudo- + bulbar) came from the idea that the symptoms seemed similar to those caused by a bulbar lesion (that is, a lesion in the medulla oblongata). Terms such as forced crying, involuntary crying, pathological emotionality, and emotional incontinence have also been used, although less frequently.
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The spino-olivary tract (historically Helweg's tract) is located in the anterior funiculus of the spinal cord and provides transmission of unconscious proprioception and is involved in balance. This tract carries proprioception information from muscles and tendons as well as cutaneous impulses to the olivary bodies. The olivary bodies known also as the olives, are located in the medulla oblongata in the brainstem. Other tracts that carry proprioception are the DSCT, cuneocerebellar tract, and the VSCT.
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The pyramidal tracts are named because they pass through the pyramids of the medulla oblongata. The corticospinal fibers when descending from the internal capsule to the brain stem, converge to a point from multiple directions giving the impression of an inverted pyramid. Involvement of the pyramidal tract at any level leads to pyramidal signs. The myelination of the pyramidal fibres is incomplete at birth and gradually progresses in cranio-caudal direction and thereby progressively gaining functionality.
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Jouvet demonstrated that the generation of REM sleep depends on an intact pontine tegmentum and that REM atonia is due to an inhibition of motor centres in the medulla oblongata. Cats with lesions around the locus coeruleus have less restricted muscle movement during REM sleep, and show a variety of complex behaviours including motor patterns suggesting that they are dreaming of attack, defence and exploration. Jouvet's research led to the identification of REM sleep behavior disorder.
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The medial lemniscus, also known as Reil's band or Reil's ribbon, is a large ascending bundle of heavily myelinated axons that decussate in the brainstem, specifically in the medulla oblongata. The medial lemniscus is formed by the crossings of the internal arcuate fibers. The internal arcuate fibers are composed of axons of nucleus gracilis and nucleus cuneatus. The axons of the nucleus gracilis and nucleus cuneatus in the medial lemniscus have cell bodies that lie contralaterally.
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In 1859 he delivered the Sydenham lecture at the Worshipful Society of Apothecaries in London. Schroeder van der Kolk's best known work is on the pathogenesis of epilepsy. Autopsy studies on the brains of people who had suffered of epilepsy in life showed changes in the medulla oblongata (part of the brainstem), and Schroeder van der Kolk stated that seizures must therefore originate in this area. Several decades later it was discovered that seizures arise from the cerebral cortex.
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Decorticate posturing, with elbows, wrists and fingers flexed, and legs extended and rotated inward Brain herniation frequently presents with abnormal posturing, a characteristic positioning of the limbs indicative of severe brain damage. These patients have a lowered level of consciousness, with Glasgow Coma Scores of three to five. One or both pupils may be dilated and fail to constrict in response to light. Vomiting can also occur due to compression of the vomiting center in the medulla oblongata.
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In the medulla oblongata, the arcuate nucleus is a group of neurons located on the anterior surface of the medullary pyramids. These nuclei are the extension of the pontine nuclei. They receive fibers from the corticospinal tract and send their axons through the anterior external arcuate fibers and medullary striae to the cerebellum via the inferior cerebellar peduncle. Arcuate nuclei are capable of chemosensitivity and have a proven role in the respiratory center controlling the breathing rate.
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The CTZ is in the medulla oblongata, which is phylogenetically the oldest part of the central nervous system. Early lifeforms developed a brainstem, or inner brain, and nothing more. This part of the brain is responsible for basic survival instincts and reactions, for example to make an organism turn its head and look where an auditory stimulus was heard. The brainstem is where the medulla is located, and therefore also the area postrema and the CTZ.
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Ventilation of the lungs in mammals occurs via the respiratory centers in the medulla oblongata and the pons of the brainstem. These areas form a series of neural pathways which receive information about the partial pressures of oxygen and carbon dioxide in the arterial blood. This information determines the average rate of ventilation of the alveoli of the lungs, to keep these pressures constant. The respiratory center does so via motor nerves which activate the diaphragm and other muscles of respiration.
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Syringomyelia is a chronic progressive degenerative disorder characterized by a fluid-filled cyst located in the spinal cord. Its symptoms include pain, weakness, numbness, and stiffness in the back, shoulders, arms or legs. Other symptoms include headaches, the inability to feel changes in the temperature, sweating, sexual dysfunction, and loss of bowel and bladder control. It is usually seen in the cervical region but can extend into the medulla oblongata and pons or it can reach downward into the thoracic or lumbar segments.
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The ventrolateral medulla, part of the medulla oblongata of the brainstem, plays a major role in regulating arterial blood pressure and breathing. It regulates blood pressure by regulating the activity of the sympathetic nerves that target the heart and peripheral blood vessels. The ventrolateral medulla consists of a rostral ventrolateral medulla (RVLM) and a caudal ventrolateral medulla (CVLM). Neurons in the RVLM project directly to preganglionic neurons in the spinal cord and maintain tonic activity in the sympathetic vasomotor nerves.
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This pathway initially follows the dorsal spino-cerebellar pathway. It is arranged as follows: proprioceptive receptors of lower limb → peripheral process → dorsal root ganglion → central process → Clarke's column → 2nd order neuron → medulla oblongata (Caudate nucleus) → 3rd order neuron → VPLN of thalamus → 4th order neuron → posterior limb of internal capsule → corona radiata → sensory area of cerebrum. The anterolateral system works somewhat differently. Its primary neurons axons enter the spinal cord and then ascend one to two levels before synapsing in the substantia gelatinosa.
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The carotid body peripheral chemoreceptors are primarily sensitive to decreases in the partial pressure of oxygen (PO2). This is in contrast to the central chemoreceptors in the medulla oblongata that are primarily sensitive to changes in pH and PCO2 (a decrease in pH and an increase in PCO2). The carotid body chemoreceptors are also sensitive to pH and PCO2, but only secondarily. More specifically, the sensitivity of carotid body chemoreceptors to decreased PO2 is greater when pH is decreased and PCO2 is increased.
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The fine touch (epicritic) is conducted by fibers of the medial lemniscus. The medial lemniscus is formed by the axons of the neurons of the gracilis and cuneatus nuclei of the medulla oblongata which receive information about light touch, vibration and conscient proprioception from the gracilis and cuneatus fasciculus of the spinal cord. This fasciculus receive the axons of the first order neuron which is located in the dorsal root ganglion that receives afferent fibers from receptors in the skin, muscles and joints.
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Clarke was the first to establish the location of the dorsal nucleus of the spinal cord, calling it "posterior vesicular columns", and described the nucleus intermediolateralis. He also differentiated the medial cuneate nucleus from the lateral cuneate nucleus (also called "Monakow's nucleus" after neuropathologist Constantin von Monakow). Clarke is credited with introducing the histological technique of mounting cleared sections of tissue in balsam media. He published numerous essays on the anatomy and physiology of the medulla oblongata and spinal cord.
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When there is a decrease in the blood's pH, a decrease in oxygen (pO2), or an increase in carbon dioxide (pCO2), the carotid bodies and the aortic bodies signal the dorsal respiratory group in the medulla oblongata to increase the volume and rate of breathing. The glomus cells have a high metabolic rate and good blood perfusion and thus are sensitive to changes in arterial blood gas tension. Glomus type II cells are sustentacular cells having a similar supportive function to glial cells.
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The term enzui is the Japanese word for medulla oblongata and giri means "to chop". Thus, an enzuigiri (often misspelled 'ensuigiri') is any attack that strikes the back of the head. It is usually associated with lighter weight class wrestlers, as well as wrestlers who have a martial arts background or gimmick. It is often used as a counter-move after a kick is blocked and the leg caught, or the initial kick is a feint to set up the real attack.
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Disruption of the anterior spinal artery leads to bilateral disruption of the corticospinal tract, causing motor deficits, and bilateral disruption of the spinothalamic tract, causing sensory deficits in the form of pain/temperature sense loss. It is called anterior spinal artery syndrome. This occurs when the disruption of the anterior spinal artery is at the level of the spinal cord. Contrast this with medial medullary syndrome, when the anterior spinal artery is occluded at the level of the medulla oblongata.
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Eating and swallowing are complex neuromuscular activities consisting essentially of three phases, an oral, pharyngeal and esophageal phase. Each phase is controlled by a different neurological mechanism. The oral phase, which is entirely voluntary, is mainly controlled by the medial temporal lobes and limbic system of the cerebral cortex with contributions from the motor cortex and other cortical areas. The pharyngeal swallow is started by the oral phase and subsequently is coordinated by the swallowing center on the medulla oblongata and pons.
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The larynx has been implicated in the production of ultrasonic vocalizations. A constriction within a rat’s larynx is thought to be the source of their ultrasonic vocalizations. As well, brain areas such as the medulla oblongata, the cortex, the amygdala, and the dorsal hippocampus, among others, play a role in 22-kHz calls specifically. Many of these brain areas/structures have been implicated in studies involving fear and anxiety, and can be associated with a larger network which deals with aversive emotions.
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In neuroanatomy, the dorsal column nuclei are a pair of nuclei in the dorsal columns in the brainstem. The name refers collectively to the cuneate nucleus and gracile nucleus, which are present at the junction between the spinal cord and the medulla oblongata. Both nuclei contain second-order neurons of the dorsal column-medial lemniscus pathway, which carries fine touch and proprioceptive information from the body to the brain. Each nucleus has an associated nerve tract, the gracile fasciculus and the cuneate fasciculus.
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Solitary tract nucleus in the dorsal respiratory group and nucleus ambiguus of the ventral respiratory group shown in their positions on the medulla oblongata. The dorsal respiratory group (DRG) has the most fundamental role in the control of respiration, initiating inspiration (inhalation). The DRG is a collection of neurons forming an elongated mass that extends most of the length of the dorsal medulla. They are near to the central canal of the spinal cord, and just behind the ventral group.
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Chandru (Rahul Madhav) is all set to marry his lover Nidhi Patel (Aavaana). Two days before the wedding, Chandru plays a leisurely cricket match with his best friends Appachan (Saiju Kurup), Seetharaman (Arjun Nandhakumar) and Mani Kantan (Rakendu). While attempting to catch a ball, Chandru falls down and gets hit on the area of the head where the medulla oblongata is located and temporarily loses his memory of the past year. In the process, he even forgets about Nidhi and the impending marriage.
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Dark Horse - A man in a blond wig and black cloak, who claims to be Hundred Eyes. As an assassin, he favors killing people by shooting them in the back of the medulla oblongata, therefore affecting the dying victim's brain nerves, causing them to be dead with the facial expression of a smile. He uses a firearm, with laser scope. Hundred Eyes rank #1 - A mysterious assassin, no one really knows who he or she is until the climax of the film.
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These reflexes help regulate short-term blood pressure. The solitary nucleus in the medulla oblongata of the brain recognizes changes in the firing rate of action potentials from the baroreceptors, and influences cardiac output and systemic vascular resistance. Baroreceptors can be divided into two categories based on the type of blood vessel in which they are located: high-pressure arterial baroreceptors and low-pressure baroreceptors (also known as cardiopulmonaryLevy, MN; Pappano, AJ. (2007) Cardiovascular Physiology, Mosby Elsevier. 9th edition, pp.172.
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The nodule (nodular lobe), or anterior end of the inferior vermis, abuts against the roof of the fourth ventricle, and can only be distinctly seen after the cerebellum has been separated from the medulla oblongata and pons. On either side of the nodule is a thin layer of white substance, named the posterior medullary velum. It is semilunar in form, its convex border being continuous with the white substance of the cerebellum; it extends on either side as far as the flocculus.
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The fibres of the spinal accessory nerve originate solely in neurons situated in the upper spinal cord, from where the spinal cord begins at the junction with the medulla oblongata, to the level of about C6. These fibres join together to form rootlets, roots, and finally the spinal accessory nerve itself. The formed nerve enters the skull through the foramen magnum, the large opening at the skull's base. The nerve travels along the inner wall of the skull towards the jugular foramen.
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The vasomotor center (VMC) is a portion of the medulla oblongata in the brainstem, that, together with the cardiovascular center and respiratory center, regulates blood pressure and other homeostatic processes. Vasomotor center is a fairly archaic term since this function relies not on a single brain structure ("center") but rather represents a network of interacting neurons. Upon increase in carbon dioxide level at central chemoreceptors, it stimulates the sympathetic system to constrict vessels. This is opposite to carbon dioxide in tissues causing vasodilatation, especially in the brain.
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The spinal cord is a long, thin, tubular structure made up of nervous tissue, which extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column. It encloses the central canal of the spinal cord, which contains cerebrospinal fluid. The brain and spinal cord together make up the central nervous system (CNS). In humans, the spinal cord begins at the occipital bone, passing through the foramen magnum and entering the spinal canal at the beginning of the cervical vertebrae.
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Pyramidal tracts The term pyramidal tracts refers to upper motor neurons that originate in the cerebral cortex and terminate in the spinal cord (corticospinal) or brainstem (corticobulbar). Nerves emerge in the cerebral cortex, pass down and may cross sides in the medulla oblongata, and travel as part of the spinal cord until they synapse with interneurons in the grey column of the spinal cord. There is some variation in terminology. The pyramidal tracts definitively encompass the corticospinal tracts, and many authors also include the corticobulbar tracts.
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This condition may not only cause cerebellar damage on a temporary or permanent basis, but can also affect other tissues of the central nervous system, those including the cerebral cortex, spinal cord and the brainstem (made up of the medulla oblongata, midbrain, and pons). Cerebellar degeneration can be attributed to a plethora of hereditary and non-hereditary conditions. More commonly, cerebellar degeneration can also be classified according to conditions that an individual may acquire during their lifetime, including infectious, metabolic, autoimmune, paraneoplastic, nutritional or toxic triggers.
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Oser and the Hungarian-Austrian, gynecologist but working in Vienna as a private lecturer Wilhelm Schlesinger (1839-1896) made the innervation of the uterus the subject of their investigations and had 1872 an excitation center in the medulla oblongata after that at the transition of the central nervous system to Spinal cord located.Oser and Schlesinger, Experimental Studies on Uterine Movement, Med. Year 1872, p. 57. They also tried to experimentally determine the triggering of uterine movements when the blood was overloaded with carbon dioxide.
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The next course of the infection differs in final and accidental hosts. In ducks, schistosomula are observed in synsacral segments of a spinal cord 3 DPI and 7–8 days latter (10–11 DPI) they reach the brain. In their final localisation (the nasal tissue), they occur 13–14 DPI and laying eggs starts 15 DPI. In mice, the first schistosomula are found in a lumbar spinal cord as early as 2 DPI and medulla oblongata is invaded the day after, but only in some individuals.
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SSTRB receptor has approximately 300 nucleotides between carboxyl terminus and transmembrane segments fewer than the original Somatostatin receptor 2. SST2A receptor is made up of 369 amino acids and 346 amino acids make up the SST2B receptor. Somatostatin receptor 2a and somatostatin receptor 2b were found in the medulla oblongata, mesencephalon, testis, cortex, hypothalamus, hippocampus and pituitary of a rodent, using reverse transcription polymerase chain reaction (RT-PCR). Somatostatin receptor 2a is highly evident in the cortex, but the somatostatin receptor 2b is not seen as much.
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The plan to use the gastrocnemius in running, jumping, knee and plantar flexing is created in the precentral gyrus in the cerebrum of the brain. Once a plan is produced, the signal is sent to and down an upper motor neuron. The signal is passed through the internal capsule and decussates, or crosses, in the medulla oblongata, specifically in the lateral corticospinal tract. The signal continues down through the anterior horn of the spinal cord where the upper motor neuron synapses with the lower motor neuron.
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The apneustic center of the lower pons appears to promote inhalation by a constant stimulation of the neurons in the medulla oblongata. The apneustic center sends signals to the dorsal group in the medulla to delay the 'switch off', the inspiratory off switch (IOS) signal of the inspiratory ramp provided by the pneumotaxic centre. It controls the intensity of breathing, giving positive impulses to the neurons involved with inhalation. The apneustic center is inhibited by pulmonary stretch receptors and also by the pneumotaxic center.
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The dentatothalamic fibers also cross over and ascend to synapse in the ventral intermediate (VI) and ventral anterior (VA) nuclei of the thalamus. The fastigioreticular fibers enter the reticular formation of the midbrain, pons, and medulla oblongata. Afferent pathways include the anterior spinocerebellar and tectocerebellar tracts. The fibers of the anterior spinocerebellar tract originate in Clarke's column of the spinal cord and cross in the anterior white commissure to the lateral funiculus, where they ascend to upper pontine levels before crossing back to enter the cerebellum through the superior peduncle.
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Hypercapnia normally triggers a reflex which increases breathing and access to oxygen (O2), such as arousal and turning the head during sleep. A failure of this reflex can be fatal, for example as a contributory factor in sudden infant death syndrome. Hypercapnia can induce increased cardiac output, an elevation in arterial blood pressure (higher levels of carbon dioxide stimulate aortic and carotid chemoreceptors with afferents -CN IX and X- to medulla oblongata with following chrono- and ino-tropic effects), and a propensity toward cardiac arrhythmias. Hypercapnia may increase pulmonary capillary resistance.
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GAS1 protein widespread distributed in adult mammalian CNS ( central nervous system). Adult mouse brain has been described expressing GAS1 mRNA, and the experiment of Natanael Zarco et al further corroborated this description. Western blot analysis is the main method which has been used in their practical and plays an significant role in successfully determining the distribution of the protein in the adult central nervous system (CNS). Olfactory bulb, caudate-putamen, cerebral cortex, hippocampus, mesencephalon, medulla oblongata, cerebellum, and cervical spinal cord has been identified as the specific expression parts of GAS1.
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The medial vestibulospinal tract is a group of descending extrapyramidal motor neurons, or efferent fibers found in the anterior funiculus, a bundle of nerve roots in the spinal cord. The medial vestibulospinal tract originates in the medial vestibular nucleus or Schwalbe's nucleus. The Schwalbe's nucleus extends from the rostral end of the inferior olivary nucleus of the medulla oblongata to the caudal portion of the pons. Medial vestibulospinal fibers join with the ipsilateral and contralateral medial longitudinal fasciculus, and descend in the anterior funiculus of the spinal cord.
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As the primary motor axons travel down through the cerebral white matter, they move closer together and form part of the posterior limb of the internal capsule. They continue down into the brainstem, where some of them, after crossing over to the contralateral side, distribute to the cranial nerve motor nuclei. (Note: a few motor fibers synapse with lower motor neurons on the same side of the brainstem). After crossing over to the contralateral side in the medulla oblongata (pyramidal decussation), the axons travel down the spinal cord as the lateral corticospinal tract.
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The cephalic phase of digestion is the stage in which the stomach responds to the mere sight, smell, taste, or thought of food. About 20% of total acid secretion occurs before food enters the stomach. These sensory and mental inputs converge on the hypothalamus to induce the responses needed for preparing the gastrointestinal tract for food processing, which relays signals to the medulla oblongata. Vagus nerve fibers from the medulla stimulate the parasympathetic nervous system of the stomach which, in turn, stimulates gastric secretion (via parietal and G cells).
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The rate and depth of breathing is automatically controlled by the respiratory centers that receive information from the peripheral and central chemoreceptors. These chemoreceptors continuously monitor the partial pressures of carbon dioxide and oxygen in the arterial blood. The sensors are, firstly, the central chemoreceptors on the surface of the medulla oblongata of the brain stem which are particularly sensitive to pH as well as the partial pressure of carbon dioxide in the blood and cerebrospinal fluid. The second group of sensors measure the partial pressure of oxygen in the arterial blood.
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The system relies on specialized neurons, known as baroreceptors chiefly in the aortic arch and carotid sinuses to monitor changes in blood pressure and relay them to the medulla oblongata. Baroreceptors are stretch receptors and respond to the pressure induced stretching of the blood vessel in which they are found. Baroreflex induced changes in blood pressure are mediated by both branches of the autonomic nervous system: the parasympathetic and sympathetic nerves. Baroreceptors are active even at normal blood pressures so that their activity informs the brain about both increases and decreases in blood pressure.
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HSD2 neurons in the nucleus of the solitary tract (HSD2=green immunofluorescence; MR=red) HSD2 neurons are a small group of neurons in the brainstem which are uniquely sensitive to the mineralocorticosteroid hormone aldosterone, through expression of HSD11B2. They are located within the caudal medulla oblongata, in the nucleus of the solitary tract (NTS). HSD2 neurons are activated during a prolonged deficit in body sodium or fluid volume, as occurs after dietary sodium deprivation or during frank hypovolemia. They are also activated by supraphysiologic stimulation of the mineralocorticoid receptor.
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He began a long series of physiological experiments to study the basic physical conditions necessary for the maintenance of life functions throughout the organism. Legallois conducted a series of animal experiments to clarify the mechanism of respiration. By decapitation of vertebrates or other targeted destruction of neural connections in the brain and spinal cord, he came to the conclusion that respiration is controlled by a respiratory center located in the medulla oblongata. His discovery was that a lesion, on a small circumscribed area in the medulla, inhibits breathing (1811).
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The spino-olivary tract is a non-specific indirect ascending pathway and is connected to olivary nuclei. The axons enter the spinal cord from the dorsal root ganglia and terminate on unknown second-order neurons in the posterior grey column. The axons from the second-order neurons cross the midline and ascend as the spino-olivary tract in the white matter at the junction of the anterior and lateral columns. The axons end by synapsing on third-order neurons in the inferior olivary nuclei in the medulla oblongata.
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The pyramidal cells of the precentral gyrus are also called upper motor neurons. The fibers of the upper motor neurons project out of the precentral gyrus ending in the brainstem, where they will decussate (intersect) within the lower medulla oblongata to form the lateral corticospinal tract on each side of the spinal cord. The fibers that do not decussate will pass through the medulla and continue on to form the anterior corticospinal tracts. The upper motor neuron descends in the spinal cord to the level of the appropriate spinal nerve root.
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Nerve fibres in the corticospinal tract originate from pyramidal cells in layer V of the cerebral cortex. Fibres arise from the primary motor cortex (about 30%), supplementary motor area and the premotor cortex (together also about 30%), and the somatosensory cortex, parietal lobe, and cingulate gyrus supplies the rest. The cells have their bodies in the cerebral cortex, and the axons form the bulk of the pyramidal tracts. The nerve axons travel from the cortex through the posterior limb of internal capsule, through the cerebral peduncle and into the brainstem and anterior medulla oblongata.
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Here they form two prominences called the medulla oblongatary pyramids. Below the prominences, the majority of axons cross over to the opposite side from which they originated, known as decussation. The axons that cross over move to the outer part of the medulla oblongata and form the lateral corticospinal tract, whereas the fibres that remain form the anterior corticospinal tract. About 80% of axons cross over and form the lateral corticospinal tract; 10% do not cross over and join the tract, and 10% of fibres travel in the anterior corticospinal tract.
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It is suggested that the selectivity of tectal prey feature detectors, type T5.2, is determined by inhibitory influences of pretectal anti-worm detectors of the type TH3. Pretectal lesions impaired the prey-selectivity. Axons from the feature sensitive/selective neurons of the optic tectum and thalamic-pretectal region then contact motor structures in the medulla oblongata, thus forming a sensorimotor interface. According to Ewert, this sensorimotor interface may serve as the "releaser" which recognizes sensory signals with assemblies of complex feature detectors and executes the corresponding motor responses.
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A post office was established at Medulla in 1881, and remained in operation until 1909. Before the post office opened, the community was called Spring Hill. The name Medulla was given to the area due to its connecting link on the stagecoach rail-line between Bartow and Fort Meade, similar to how the medulla oblongata (in the lower part of the brain) connects with spinal cord. Medulla saw a period of rapid growth throughout the 1990s and early 2000s with development of Deer Brooke, a mega deed restricted community.
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Various parts of the cerebrum process sensory input, such as smell in the olfactory lobe and sight in the optic lobe, and it is additionally the centre of behaviour and learning. The cerebellum is the center of muscular coordination and the medulla oblongata controls some organ functions including heartbeat and respiration. The brain sends signals through the spinal cord and nerves to regulate activity in the rest of the body. The pineal body, known to regulate sleep patterns in humans, is thought to produce the hormones involved in hibernation and aestivation in amphibians.
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Proprioceptive information is taken to the spinal cord via central processes of dorsal root ganglia (first order neurons). These central processes travel through the dorsal horn where they synapse with second order neurons of Clarke's nucleus. Axon fibers from Clarke's Nucleus convey this proprioceptive information in the spinal cord in the peripheral region of the funiculus posterior ipsilaterally. The fibers continue to course through the medulla oblongata of the brainstem, at which point they pass through the inferior cerebellar peduncle and into the cerebellum, where unconscious proprioceptive information is processed.
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As little of the medication crosses the blood brain barrier it has less effect on the brain and therefore has reduced occurrence of the centrally mediated effects (such as delusions, somnolence, and inhibition of motor-functions) which hinder the usefulness of some other anticholinergic drugs. Hyoscine butylbromide is still capable of impacting the chemoreceptor trigger zone due to the lack of a well-developed blood-brain-barrier in the medulla oblongata, which potentiates the antiemetic effects that it produces via local action on the smooth muscle of the gastrointestinal tract.
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The majority of adult patients experiencing CNH have clinical histories of infiltrative, expanding tumors of the cortex, primarily involving the brainstem. Over three-quarters of the cases reported since the discovery of CNH by Plum and Swanson had tumors clearly involving the pons, with specific consideration given to pathology of the pontine tegmentum. CNH was also reported in patients with tumors affecting the medulla oblongata. Though a diagnosis of CNH is rarely considered without evidence of brainstem infiltration, there have been other reported cases of CNH not directly involving the pons or medulla.
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The modern rediscovery of CSF is credited to Emanuel Swedenborg. In a manuscript written between 1741 and 1744, unpublished in his lifetime, Swedenborg referred to CSF as "spirituous lymph" secreted from the roof of the fourth ventricle down to the medulla oblongata and spinal cord. This manuscript was eventually published in translation in 1887. Albrecht von Haller, a Swiss physician and physiologist, made note in his 1747 book on physiology that the "water" in the brain was secreted into the ventricles and absorbed in the veins, and when secreted in excess, could lead to hydrocephalus.
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The thickness of the aorta requires an extensive network of tiny blood vessels called vasa vasorum, which feed the tunica externa and tunica media outer layers of the aorta. The aortic arch contains baroreceptors and chemoreceptors that relay information concerning blood pressure and blood pH and carbon dioxide levels to the medulla oblongata of the brain. This information is processed by the brain and the autonomic nervous system mediates the homeostatic responses. Within the tunica media, smooth muscle and the extracellular matrix are quantitatively the largest components of the aortic vascular wall.
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The area postrema is located in the caudal medulla oblongata near the junction of the brainstem and the spinal cord. In humans and in most other mammals that have been studied, it consists of swellings on either wall of the fourth ventricle. In rodents and lagomorphs, however, the area postrema forms a midline structure dorsal to the obex. When viewed histologically for its capillary distribution and morphology, the area postrema has numerous subregions separated according to capillary permeability, rates of blood flow, and duration of blood transit through respective capillary beds.
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3D Medical Animation Still Shot Showing Different Parts of Mid-Brain The brainstem (or brain stem) is the posterior part of the brain, continuous with the spinal cord. In the human brain the brainstem is composed of the midbrain, the pons, and the medulla oblongata. The midbrain is continuous with the thalamus of the diencephalon through the tentorial notch, and sometimes the diencephalon is included in the brainstem. The brainstem is a very small component of the brain, making up only around 2.6 percent of its total weight.
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The fibers of the vestibular nerve enter the medulla oblongata on the medial side of those of the cochlear, and pass between the inferior peduncle and the spinal tract of the trigeminal nerve. They then divide into ascending and descending fibers. The latter end by arborizing around the cells of the medial nucleus, which is situated in the area acustica of the rhomboid fossa. The ascending fibers either end in the same manner or in the lateral nucleus, which is situated lateral to the area acustica and farther from the ventricular floor.
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The biosynthesis of adrenaline involves a series of enzymatic reactions. In chemical terms, adrenaline is one of a group of monoamines called the catecholamines. Adrenaline is synthesized in the chromaffin cells of the adrenal medulla of the adrenal gland and a small number of neurons in the medulla oblongata in the brain through a metabolic pathway that converts the amino acids phenylalanine and tyrosine into a series of metabolic intermediates and, ultimately, adrenaline. Tyrosine is first oxidized to L-DOPA by Tyrosine hydroxylase, this is the rate-limiting step.
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The I1 receptor appears to be a G protein-coupled receptor that is localized on the plasma membrane. It may be coupled to PLA2 signalling and thus prostaglandin synthesis. In addition, activation inhibits the sodium- hydrogen antiporter and enzymes of catecholamine synthesis are induced, suggesting that the I1 receptor may belong to the neurocytokine receptor family, since its signaling pathways are similar to those of interleukins. It is found in the neurons of the reticular formation, the dorsomedial medulla oblongata, adrenal medulla, renal epithelium, pancreatic islets, platelets, and the prostate.
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Intraparenchymal bleeds within the medulla oblongata are almost always fatal, because they cause damage to cranial nerve X, the vagus nerve, which plays an important role in blood circulation and breathing. This kind of hemorrhage can also occur in the cortex or subcortical areas, usually in the frontal or temporal lobes when due to head injury, and sometimes in the cerebellum.Graham DI and Gennareli TA. Chapter 5, "Pathology of Brain Damage After Head Injury" Cooper P and Golfinos G. 2000. Head Injury, 4th Ed. Morgan Hill, New York.
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Climbing fibers are the name given to a series of neuronal projections from the inferior olivary nucleus located in the medulla oblongata. Image of Parallel fiber These axons pass through the pons and enter the cerebellum via the inferior cerebellar peduncle where they form synapses with the deep cerebellar nuclei and Purkinje cells. Each climbing fiber will form synapses with 1-10 Purkinje cells. Early in development, Purkinje cells are innervated by multiple climbing fibers, but as the cerebellum matures, these inputs gradually become eliminated resulting in a single climbing fiber input per Purkinje cell.
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In fact, when herniation is visible on a CT scan, the prognosis for a meaningful recovery of neurological function is poor. The patient may become paralyzed on the same side as the lesion causing the pressure, or damage to parts of the brain caused by herniation may cause paralysis on the side opposite the lesion. Damage to the midbrain, which contains the reticular activating network which regulates consciousness, will result in coma. Damage to the cardio-respiratory centers in the medulla oblongata will cause respiratory arrest and (secondarily) cardiac arrest.
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From the anterior portion of the medulla oblongata, the glossopharyngeal nerve passes laterally across or below the flocculus, and leaves the skull through the central part of the jugular foramen. From the superior and inferior ganglia in jugular foramen, it has its own sheath of dura mater. The inferior ganglion on the inferior surface of petrous part of temporal is related with a triangular depression into which the aqueduct of cochlea opens. On the inferior side, the glossopharyngeal nerve is lateral and anterior to the vagus nerve and accessory nerve.
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The hypoglossal nerve is derived from the first pair of occipital somites, collections of mesoderm that form next to the main axis of an embryo during development. The musculature it supplies develop as the hypoglossal cord from the myotomes of the first four pairs of occipital somites. The nerve is first visible as a series of roots in the fourth week of development, which have formed a single nerve and link to the tongue by the fifth week. The hypoglossal nucleus is derived from the basal plate of the embryonic medulla oblongata.
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The vestibulocochlear nerve consists mostly of bipolar neurons and splits into two large divisions: the cochlear nerve and the vestibular nerve. Cranial nerve 8, the vestibulocochlear nerve, goes to the middle portion of the brainstem called the pons, (which then is largely composed of fibers going to the cerebellum). The 8th cranial nerve runs between the base of the pons (the middle portion of the brainstem) and medulla oblongata (the lower portion of the brainstem). This junction between the pons, medulla, and cerebellum that contains the 8th nerve is called the cerebellopontine angle.
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The chemoreceptor trigger zone (CTZ) is an area of the medulla oblongata that receives inputs from blood-borne drugs or hormones, and communicates with other structures in the vomiting center to initiate vomiting. The CTZ is located within the area postrema, which is on the floor of the fourth ventricle and is outside of the blood–brain barrier. It is also part of the vomiting center itself. The neurotransmitters implicated in the control of nausea and vomiting include acetylcholine, dopamine, histamine (H1 receptor), substance P (NK-1 receptor), and serotonin (5-HT3 receptor).
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Since the CTZ is located in the area postrema, a sensory circumventricular organ, it does not have a blood–brain barrier. This means that large polar molecules, such as emetic toxins, can diffuse through to and reach the CTZ quite easily. This is because the medulla oblongata is located in the area of the brain, the most inferior portion, which does not have a robust and highly developed blood-brain barrier. Without this barrier, emetic drugs and toxins are free to interact with a receptor (biochemistry), or multiple receptors located in the CTZ.
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Descending motor pathways carry motor signals from the brain down the spinal cord and to the target muscle or organ. They typically consist of an upper motor neuron and a lower motor neuron. The lateral corticospinal tract is a descending motor pathway that begins in the cerebral cortex, decussates in the pyramids of the lower medulla (also known as the medulla oblongata or the cervicomedullary junction, which is the most posterior division of the brain) and proceeds down the contralateral side of the spinal cord. It is the largest part of the corticospinal tract.
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The reticular formation is a set of interconnected nuclei that are located throughout the brainstem. It is not anatomically well defined, because it includes neurons located in different parts of the brain. The neurons of the reticular formation make up a complex set of networks in the core of the brainstem that extend from the upper part of the midbrain to the lower part of the medulla oblongata. The reticular formation includes ascending pathways to the cortex in the ascending reticular activating system (ARAS) and descending pathways to the spinal cord via the reticulospinal tracts.
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The apex of the posterior grey column, one of the three grey columns of the spinal cord, is capped by a V-shaped or crescentic mass of translucent, gelatinous neuroglia, termed the substantia gelatinosa of Rolando (or SGR) (or gelatinous substance of posterior horn of spinal cord), which contains both neuroglia cells, and small nerve cells. The gelatinous appearance is due to a very low concentration of myelinated fibers. It extends the entire length of the spinal cord and into the medulla oblongata where it becomes the spinal nucleus of the trigeminal nerve. It is named after Luigi Rolando.
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It receives information from the caudal solitary tract and transmits signals mainly to the medial hypothalamus but also to the lateral hypothalamus and many of the nuclei targeted by the medial parabrachial nucleus. The subparabrachial nucleus, also known as the Kölliker-Fuse nucleus and diffuse reticular nucleus, is one of the three parabrachial nuclei between the midbrain and the pons. The subparabrachial nucleus regulates the breathing rate. It receives signals from the caudal, cardio-respiratory part of the solitary nucleus and sends signals to the lower medulla oblongata, the spinal cord, the amygdala and the lateral hypothalamus.
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Under most conditions, the partial pressure of carbon dioxide (PCO2), or concentration of carbon dioxide, controls the respiratory rate. The peripheral chemoreceptors that detect changes in the levels of oxygen and carbon dioxide are located in the arterial aortic bodies and the carotid bodies. Central chemoreceptors are primarily sensitive to changes in the pH in the blood, (resulting from changes in the levels of carbon dioxide) and they are located on the medulla oblongata near to the medullar respiratory groups of the respiratory center. Information from the peripheral chemoreceptors is conveyed along nerves to the respiratory groups of the respiratory center.
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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.
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According to Gerald Casale on the Devo website: > It was designed according to ancient ziggurat mound proportions used in > votive worship. Like the mounds it collects energy and recirculates it. In > this case the Dome collects the Orgone energy that escapes from the crown of > the human head and pushes it back into the Medulla Oblongata for increased > mental energy. It's very important that you use the foam insert...or better > yet, get a plastic hardhat liner, adjust it to your head size and affix it > with duct tape or Super Glue to the inside of the Dome.
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In 1997, Dan began teaching in the Molecular and Cell Biology Department of the University of California, Berkeley, and later became the Paul Licht Distinguished Professor. She is also a Howard Hughes Medical Institute (HHMI) Investigator. Her research projects include neural circuits controlling sleep and the function of the prefrontal cortex. In a 2015 research paper published in Nature, Dan and her team found that activation of GABAergic neurons in the medulla oblongata brain region of sleeping mice causes them to enter REM sleep or the dream state, whereas the same activation in mice when they are awake causes them to eat more.
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Perihypoglossal nuclei (nuclei perihypoglossales), called also perihypoglossal complex or perihypoglossal nuclear complex or satellite nuclei is a group of neurons in the floor of the fourth ventricle, in close proximity to the nucleus of the hypoglossal nerve in the gray substance of the medulla oblongata, all of which contain cells with characteristics suggestive of reticular connections. The complex includes three nuclei: the intercalated nucleus, the nucleus prepositus, and the sublingual nucleus. The nucleus prepositus is the largest of the three. Perihypoglossal nuclei receive afferents from the cerebral cortex, vestibular nuclei, accessory oculomotor nuclei, and paramedian pontine reticular formation.
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The role of electricity in nerves was first observed in dissected frogs by Luigi Galvani, Lucia Galeazzi Galvani and Giovanni Aldini in the second half of the 18th century. In 1811, César Julien Jean Legallois for the first time define a specific function in a brain region. He studied respiration in animal dissection and lesions, and found the center of respiration in the medulla oblongata. Between 1811 and 1824, Charles Bell and François Magendie discovered through dissection and vivisection that the ventral roots in spine transmit motor impulses and the posterior roots receive sensory input (Bell- Magendie law).
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With the two fragments of the jaws found, only 14 teeth in total were reported with five in the posterior fragment and nine in the anterior one. The basioccipital region is defined as typically archosaurian, with a rounded condyle, a rather elongated surface above it for the medulla oblongata, and an extended ventral plate. These basioccipital characteristics are seen in extinct archosaurians such as primitive theropod dinosaurs as well as seen in crocodylians. It can be seen that the skull would have been relatively large which was compared to carnosaurian dinosaurs, which too had fairly large skulls.
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The cuneate fasciculus is triangular on transverse section, and lies between the gracile fasciculus and the posterior column, its base corresponding with the surface of the spinal cord. Its fibers, larger than those of the gracile fasciculus, are mostly derived from the same source, viz., the posterior nerve roots. Some ascend for only a short distance in the tract, and, entering the gray matter, come into close relationship with the cells of the dorsal nucleus, while others can be traced as far as the medulla oblongata, where they end in the gracile nucleus and cuneate nucleus.
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The internal arcuate fibers or internal arcuate tract are the axons of second- order sensory neurons that compose the gracile and cuneate nuclei of the medulla oblongata. These second-order neurons begin in the gracile and cuneate nuclei in the medulla. They receive input from first-order sensory neurons, which provide sensation to many areas of the body and have cell bodies in the dorsal root ganglia of the dorsal root of the spinal nerves. Upon decussation (crossing over) from one side of the medulla to the other, also known as the sensory decussation, they are then called the medial lemniscus.
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There is speculation of several mechanisms by which the brain cells could be lost. One mechanism consists of an abnormal accumulation of the protein alpha- synuclein bound to ubiquitin in the damaged cells. This insoluble protein accumulates inside neurones forming inclusions called Lewy bodies. According to the Braak staging, a classification of the disease based on pathological findings proposed by Heiko Braak, Lewy bodies first appear in the olfactory bulb, medulla oblongata and pontine tegmentum; individuals at this stage may be asymptomatic or may have early non-motor symptoms (such as loss of sense of smell, or some sleep or automatic dysfunction).
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It winds backward around the upper part of the medulla oblongata, passing between the origins of the vagus nerve and the accessory nerve, over the inferior cerebellar peduncle to the undersurface of the cerebellum, where it divides into two branches. The medial branch continues backward to the notch between the two hemispheres of the cerebellum; while the lateral supplies the under surface of the cerebellum, as far as its lateral border, where it anastomoses with the anterior inferior cerebellar and the superior cerebellar branches of the basilar artery. Branches from this artery supply the choroid plexus of the fourth ventricle.
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The accessory cuneate nucleus is located lateral to the cuneate nucleus in the medulla oblongata at the level of the sensory decussation (the crossing fibers of the posterior column/medial lemniscus tract). It receives sensory input about position and movement (proprioception) from the upper limb by way of cervical spinal nerves and transmits that information to the cerebellum. These fibers are called cuneocerebellar (cuneate nucleus → cerebellum) fibers. In this function, the accessory cuneate nucleus is the upper extremity equivalent of Clarke's column, also called the nucleus thoracicus, which is the source of spinocerebellar connections for proprioception from the lower limb.
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The fibres that form the spinal accessory nerve are formed by lower motor neurons located in the upper segments of the spinal cord. This cluster of neurons, called the spinal accessory nucleus, is located in the lateral aspect of the anterior horn of the spinal cord, and stretches from where the spinal cord begins (at the junction with the medulla) through to the level of about C6. The lateral horn of high cervical segments appears to be continuous with the nucleus ambiguus of the medulla oblongata, from which the cranial component of the accessory nerve is derived.
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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.
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This acts on the kidneys to inhibit the secretion of renin and aldosterone causing the release of sodium, and accompanying water into the urine, thereby reducing the blood volume. This information is then conveyed, via afferent nerve fibers, to the solitary nucleus in the medulla oblongata. From here motor nerves belonging to the autonomic nervous system are stimulated to influence the activity of chiefly the heart and the smallest diameter arteries, called arterioles. The arterioles are the main resistance vessels in the arterial tree, and small changes in diameter cause large changes in the resistance to flow through them.
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This cessation of breathing is due to the underdevelopment of the body's respiratory control center, the medulla oblongata in premature infants. Ample research also suggests that caffeine significantly reduces the occurrence of bronchopulmonary dysplasia, which is a chronic lung disorder defined by the need for supplemental oxygen after a postmenstrual age of 36 weeks. Bronchopulmonary dysplasia is common in infants with low birth weight (<2500g) and very low birth weight (<1500g) who received mechanical ventilator machines to help manage respiratory distress syndrome. Currently, there is no treatment for bronchopulmonary dysplasia, as it is generally considered that the risks of treatment outweigh the necessity for using a mechanical ventilator.
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The anterior inferior cerebellar artery (AICA) is one of three pairs of arteries that supplies blood to the cerebellum. It arises from the basilar artery on each side at the level of the junction between the medulla oblongata and the pons in the brainstem. It has a variable course, passing backward to be distributed to the anterior part of the undersurface of the cerebellum, anastomosing with both the posterior inferior cerebellar (PICA) branch of the vertebral artery and the superior cerebellar artery. It also gives off the internal auditory or labyrinthine artery in most cases; however, the labyrinthine artery can less commonly emerge as a branch of the basilar artery.
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The earlobe, as a body part built of epithelium and connective tissue, might appear to be derived from dermatome. But this is not the case, as in the surrounding tissue there are no somites and thus no dermatome. In this area, the dermis is derived from cells of mesenchymal cells: the mesenchyme is derived from the sclerotome and splanchnopleura located in the nearby regions of the torso. The earlobe as a body part arises and develops in the vicinity of auricular follicle, as a result of cascade induction: # The first-level inductor is the central segment of Archenteron's roof, which induces the production of the Medulla oblongata (part of the Hindbrain).
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It involved the spinal cord, medulla oblongata and the basal ganglia, and had the ability to reflect sensory impressions into the motor nervous system by definite laws unique to itself, and also independent of consciousness. Prochaska demonstrated that reflex worked without a brain, but could not work without a spinal cord, and summarized that voluntary behavior was a brain function, while reflex was spinal-based. One of Prochaska's better-known writings is Dissertation on the Functions of the Nervous System, a work that was later combined with John Augustus Unzer's The Principles of Physiology as one publication, being translated and edited by English physiologist Thomas Laycock (1812–1876).
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In his classic early 20th century work on psychotropic drugs Phantastica, German pharmacologist Louis Lewin recounts the curious and tragic case - seemingly unique in the literature - of an individual who became addicted (in a manner far more often associated with opiates) to a Gelsemium preparation: > during a severe attack of rheumatism a man took a large quantity of an > alcoholic tincture of Gelsemium sempervirens a plant which is liable to act > on the brain and the medulla oblongata. Noticing an appreciable result he > continued to take it, and finally became a slave to the drug. He gradually > augmented the quantity, and reached 30 gr. of the tincture in one dose.
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Heart rate is determined by the medulla oblongata and part of the pons, two organs located inferior to the hypothalamus on the brain stem. Heart rate is important for basal metabolic rate and resting metabolic rate because it drives the blood supply, stimulating the Krebs cycle. During exercise that achieves the anaerobic threshold, it is possible to deliver substrates that are desired for optimal energy utilization. The anaerobic threshold is defined as the energy utilization level of heart rate exertion that occurs without oxygen during a standardized test with a specific protocol for accuracy of measurement, such as the Bruce Treadmill protocol (see metabolic equivalent of task).
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Arnold was the author of 120 articles in the fields of histology and pathological anatomy.Julius Arnold @ Who Named It With Austrian pathologist, Hans Chiari, his name is lent to a condition known as Arnold–Chiari malformation, a disorder that takes place when the cerebellar tonsils and the medulla oblongata protrude through the foramen magnum into the spinal canal, without displacing the lower brain stem.Arnold-Chiari malformation @ Who Named It Arnold described his pathological findings associated with the disorder from an infant who died shortly after delivery. He published his account of the disorder in an 1894 paper titled "Myelocyste, Transposition von Gewebskeimen und Sympodie".
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The anterior external arcuate fibers (ventral external arcuate fibers) vary as to their prominence: in some cases they form an almost continuous layer covering the medullary pyramids and olivary body, while in other cases they are barely visible on the surface. Most of them reach the surface by way of the anterior median fissure, and arch backward over the pyramid. Reinforced by others which emerge between the pyramid and olive, they pass backward over the olive and lateral district of the medulla oblongata, and enter the inferior peduncle. As the fibers arch across the pyramid, they enclose a small nucleus which lies in front of and medial to the pyramid.
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Of all the different brain regions, the cerebral cortex shows the largest evolutionary variation and has evolved most recently. In contrast to the highly conserved circuitry of the medulla oblongata, for example, which serves critical functions such as regulation of heart and respiration rates, many areas of the cerebral cortex are not strictly necessary for survival. Thus, the evolution of the cerebral cortex has seen the advent and modification of new functional areas—particularly association areas that do not directly receive input from outside the cortex. A key theory of cortical evolution is embodied in the radial unit hypothesis and related protomap hypothesis, first proposed by Rakic.
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He also penned Psychiatrie für Ärzte und Studirende, a textbook that was published in four editions between 1894 and 1911. In his writings, Ziehen is credited with introducing the terms "affective psychosis" and "psychopathic constitution".BioMed Experts Theodor Ziehen as child and adolescent psychiatrist Along with neurologist Hermann Oppenheim, the "Ziehen- Oppenheim syndrome" is named, a condition defined as genetic torsion dystonia (spasms) due to a lesion of the basal ganglia. Ziehen-Oppenheim syndrome @ Who Named It As an anatomist, Ziehen published a series of extensive descriptions of the human spinal cord, medulla oblongata, pons and cerebellum in Karl von Bardeleben's handbook of human anatomy (Handbuch der Anatomie des Menschen).
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The brain regions of sharks and humans The central nervous system (CNS) of fish contains a spinal cord, medulla oblongata, and the brain, divided into telencephalon, diencephalon, mesencephalon and cerebellum. In fish, similar to other vertebrates, nociception travels from the peripheral nerves along the spinal nerves and is relayed through the spinal cord to the thalamus. The thalamus is connected to the telencephalon by multiple connections through the grey matter pallium, which has been demonstrated to receive nerve relays for noxious and mechanical stimuli. The major tracts that convey pain information from the periphery to the brain are the spinothalamic tract (body) and the trigeminal tract (head).
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Sterzi showed that, both in petromyzontes and in the precocious developmental stages of higher vertebrates, the spinal medulla receives its blood from the superficial vessels. It is only in later stages that vessels penetrate the spinal medulla in various patterns. He also demonstrated that, whereas in lower vertebrates there are portions of the spinal medulla supplied by venous blood and others by the arterial one, in later phylo and ontogenetic stages the blood supply becomes uniform for the formation of longitudinal tracts among the primitive metameric systems. In 1913, Sterzi published a study on the development of mammalian central arteries in the spinal medulla, medulla oblongata, and pons (Sterzi, 1913).
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In the superior region of the pons is the locus coeruleus, which due to its concentration of noradrenaline has a sky blue appearance, visible (in a colour closer to teal) through the floor of the ventricle, superiorly to the superior fovea. The internal part of the facial nerve bulges into the ventricle, forming the facial colliculus, in the process of looping around the abducens nucleus within the inferior region of the Pons. The medulla oblongata is located behind the inferior portion of the floor (and continues caudally of the ventricle). Medullary striae emerge via the median sulcus and run transversely across the floor to become part of the inferior cerebellar peduncle.
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The respiratory center Changes in the levels of oxygen, carbon dioxide, and plasma pH are sent to the respiratory center, in the brainstem where they are regulated. The partial pressure of oxygen and carbon dioxide in the arterial blood is monitored by the peripheral chemoreceptors (PNS) in the carotid artery and aortic arch. A change in the partial pressure of carbon dioxide is detected as altered pH in the cerebrospinal fluid by central chemoreceptors (CNS) in the medulla oblongata of the brainstem. Information from these sets of sensors is sent to the respiratory center which activates the effector organs – the diaphragm and other muscles of respiration.
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On its lower surface, about 1 cm. in front of the foramen magnum, is the pharyngeal tubercle which gives attachment to the fibrous raphe of the pharynx. On either side of the middle line the longus capitis and rectus capitis anterior are inserted, and immediately in front of the foramen magnum the anterior atlantooccipital membrane is attached. The upper surface, which constitutes the lower half of the clivus, presents a broad, shallow groove which inclines upward and forward from the foramen magnum; it supports the medulla oblongata, and near the margin of the foramen magnum gives attachment to the tectorial membrane On the lateral margins of this surface are faint grooves for the inferior petrosal sinuses.
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In vertebrates, the cerebellar vermis develops between two bilaterally symmetrical formations located dorsal to the upper end of the medulla oblongata, or rhombencephalon. This is the region of termination for the fibers of the vestibular nerve and lateral line nerves; thus, these are the oldest afferent paths to the cerebellum and cerebellar vermis. In bony fish, or teleosts, it has been proposed that the cerebellar auricles, which receive a large amount of input from the vestibulolateral line system, constitute the vestibulocerebellum and are homologues of the flocculonodular lobe of higher vertebrates along with the corpus cerebelli, which receives spinocerebellar and tectocerebellar fibers. The labyrinth and the lateral line organs of lampreys have structural and functional similarity.
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The cells of the dorsal nucleus of vagus nerve are spindle-shaped, like those of the posterior column of the spinal cord, and the nucleus is usually considered as representing the base of the posterior column. It measures about 2 cm. in length, and in the lower, closed part of the medulla oblongata is situated behind the dorsal motor nucleus of the vagus; whereas in the upper, open part it lies lateral to that nucleus, and corresponds to an eminence, named the vagal trigone (ala cinerea, not to be confused with tuberculum cinereum nor tuber cinereum), in the rhomboid fossa. The vagal trigone is separated from the area postrema by a narrow strip of thickened ependyma – the funiculus separans.
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Ventilatory rate (respiratory minute volume) is tightly controlled and determined primarily by blood levels of carbon dioxide as determined by metabolic rate. Blood levels of oxygen become important in hypoxia. These levels are sensed by central chemoreceptors on the surface of the medulla oblongata for increased pH (indirectly from the increase in CSF of carbon dioxide), and the peripheral chemoreceptors in the arterial blood for oxygen and carbon dioxide. Afferent neurons from the peripheral chemoreceptors are via the glossopharyngeal nerve (CN IX) and the vagus nerve (CN X). Levels of CO2 rise in the blood when the metabolic use of O2, and the production of CO2 is increased during, for example, exercise.
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Worried, Fry tells her that he needs to find out something, leaves, and, using his own micro-droid, enters his own body. Fry confronts the worm leader and engages him in a sword fight after asking the worms to leave so he can learn if Leela loves him or just what they have made of him; he eventually coerces the worms into leaving by threatening to kill himself by destroying the medulla oblongata. With the worms gone, Fry returns to Leela's apartment and explains to her about the worms, and his decision to dispose of them. His awkward attempts at being romantic end when he mentions his previous relationship with Amy, and Leela kicks him out of her apartment.
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The term "ataxia" is sometimes used in a broader sense to indicate lack of coordination in some physiological process. Examples include optic ataxia (lack of coordination between visual inputs and hand movements, resulting in inability to reach and grab objects) and ataxic respiration (lack of coordination in respiratory movements, usually due to dysfunction of the respiratory centres in the medulla oblongata). Optic ataxia may be caused by lesions to the posterior parietal cortex, which is responsible for combining and expressing positional information and relating it to movement. Outputs of the posterior parietal cortex include the spinal cord, brain stem motor pathways, pre-motor and pre- frontal cortex, basal ganglia and the cerebellum.
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Axons from the upper body enter at or above T6 and travel up the posterior column on the outside of the gracile fasciculus in a more lateral section called the cuneate fasciculus. These fasciculi are in an area known as the posterior funiculus that lies between the posterolateral and the posterior median sulcus. They are separated by a partition of glial cells which places them on either side of the posterior intermediate sulcus. The column reaches the junction between the spinal cord and the medulla oblongata, where lower body axons in the gracile fasciculus connect (synapse) with neurons in the gracile nucleus, and upper body axons in the cuneate fasciculus synapse with neurons in the cuneate nucleus.
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Regardless, Lewy bodies are widely recognized as a pathological marker of Parkinson's disease. Lewy bodies first appear in the olfactory bulb, medulla oblongata, and pontine tegmentum; patients at this stage are asymptomatic. As the disease progresses, Lewy bodies develop in the substantia nigra, areas of the midbrain and basal forebrain, and in the neocortex. This mechanism is substantiated by the facts that α-synuclein lacks toxicity when unable to form aggregates; that heat-shock proteins, which assist in refolding proteins susceptible to aggregation, beneficially affect PD when overexpressed; and that reagents which neutralize aggregated species protect neurons in cellular models of α-synuclein overexpression. Alpha- synuclein appears to be a key link between reduced DNA repair and Parkinson’s disease.
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The myenteric plexus (or Auerbach's plexus) provides motor innervation to both layers of the muscular layer of the gut, having both parasympathetic and sympathetic input (although present ganglion cell bodies belong to parasympathetic innervation, fibers from sympathetic innervation also reach the plexus), whereas the submucous plexus has only parasympathetic fibers and provides secretomotor innervation to the mucosa nearest the lumen of the gut. It arises from cells in the vagal trigone also known as the nucleus ala cinerea, the parasympathetic nucleus of origin for the tenth cranial nerve (vagus nerve), located in the medulla oblongata. The fibers are carried by both the anterior and posterior vagal nerves. The myenteric plexus is the major nerve supply to the gastrointestinal tract and controls GI tract motility.
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Serotonergic cell groups refer to collections of neurons in the central nervous system that have been demonstrated by histochemical fluorescence to contain the neurotransmitter serotonin (5-hydroxytryptamine). Since they are for the most part localized to classical brainstem nuclei, particularly the raphe nuclei, they are more often referred to by the names of those nuclei than by the B1-9 nomenclature. These cells appear to be common across most mammals and have two main regions in which they develop; one forms in the mesencephlon and the rostral pons (find articles/links) and the other in the medulla oblongata and the caudal pons.R. Nieuwenhuys, J. Voogd, C. Van Huijzen, The human central nervous system: a synopsis and atlas (Springer Science & Business Media, 2007).
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Some of the axons of the cells of the lateral nucleus, and possibly also of the medial nucleus, are continued upward through the inferior peduncle to the roof nuclei of the opposite side of the cerebellum, to which also other fibers of the vestibular root are prolonged without interruption in the nuclei of the medulla oblongata. A second set of fibers from the medial and lateral nuclei end partly in the tegmentum, while the remainder ascend in the medial longitudinal fasciculus to arborize around the cells of the nuclei of the oculomotor nerve. Fibers from the lateral vestibular nucleus also pass via the vestibulospinal tract, to anterior horn cells at many levels in the spinal cord, in order to co-ordinate head and trunk movements.
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Only some parts of the brain were preserved; the cerebellar and celebral expansions were best preserved, whereas the olfactory lobes and medulla oblongata were missing or nearly so. The neural tissues seemed to be very tightly packed, indicating an EC closer to five (with hadrosaurs having even higher ECs), nearly matching that of the most intelligent non-avian theropods. Though it was noted this was in-line with their complex behaviour, as had been noted by Hopson, it was cautioned the dense packing may have been an artifact of preservation, and the original lower estimates were considered more accurate. Some of the complex behaviours ascribed can be seen to some extent in modern crocodilians, who fall near the original numbers.
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The neural plate folds inward to form the neural groove, and then the lips that line the groove merge to enclose the neural tube, a hollow cord of cells with a fluid-filled ventricle at the center. At the front end, the ventricles and cord swell to form three vesicles that are the precursors of the prosencephalon (forebrain), mesencephalon (midbrain), and rhombencephalon (hindbrain). At the next stage, the forebrain splits into two vesicles called the telencephalon (which will contain the cerebral cortex, basal ganglia, and related structures) and the diencephalon (which will contain the thalamus and hypothalamus). At about the same time, the hindbrain splits into the metencephalon (which will contain the cerebellum and pons) and the myelencephalon (which will contain the medulla oblongata).
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An opioid epidemic is the overuse or misuse of addictive opioid drugs with significant medical, social and economic consequences, including overdose deaths. Opioids are a diverse class of moderately strong painkillers, including oxycodone (commonly sold under the trade names OxyContin and Percocet), hydrocodone (Vicodin, Norco) and a very strong painkiller, fentanyl, which is synthesized to resemble other opiates such as opium-derived morphine and heroin. The potency and availability of these substances, despite their high risk of addiction and overdose, have made them popular both as medical treatments and as recreational drugs. Due to their sedative effects on the part of the brain which regulates breathing, the respiratory center of the medulla oblongata, opioids in high doses present the potential for respiratory depression and may cause respiratory failure and death.
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These secondary neurons are situated in the posterior horn, specifically in the Rexed laminae regions I, IV, V and VI. Region II is primarily composed of Golgi II interneurons, which are primarily for the modulation of pain, and largely project to secondary neurons in regions I and V. Secondary neurons from regions I and V decussate across the anterior white commissure and ascend in the (now contralateral) lateral spinothalamic tract. These fibers will ascend through the brainstem, including the medulla oblongata, pons and midbrain, as the spinal lemniscus until synapsing in the ventroposteriorlateral (VPL) nucleus of the thalamus. The third order neurons in the thalamus will then project through the internal capsule and corona radiata to various regions of the cortex, primarily the main somatosensory cortex, Brodmann areas 3, 1, and 2.
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Fibres from the ventral motor cortex travel with the corticospinal tract through the internal capsule, but terminate in a number of locations in the midbrain (cortico-mesencephalic tract), pons (Corticopontine tract), and medulla oblongata (cortico-bulbar tract). The upper motor neurons of the corticobulbar tract synapse with interneurons or directly with the lower motor neurons located in the motor cranial nerve nuclei, namely oculomotor, trochlear, motor nucleus of the trigeminal nerve, abducens, facial nerve and accessory and in the nucleus ambiguus to the hypoglossal, vagus and accessory nerves. These nuclei are supplied by nerves from both sides of the brain, with the exception of the parts of the facial nerve that control muscles of the lower face. These muscles are only innervated by nerves from the contralateral (opposite) side of the cortex.
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ALS is a motor neuron disease, also spelled "motor neurone disease", which is a group of neurological disorders that selectively affect motor neurons, the cells that control voluntary muscles of the body. Motor neuron diseases include amyotrophic lateral sclerosis (ALS), primary lateral sclerosis (PLS), progressive muscular atrophy (PMA), progressive bulbar palsy, pseudobulbar palsy, and monomelic amyotrophy (MMA). ALS itself can be classified in a few different ways: by how fast the disease progresses (slow vs fast progressors), by whether it is inherited or sporadic, and by where it starts. In about 25% of cases, muscles in the face, mouth, and throat are affected first because motor neurons in the part of the brain stem called the medulla oblongata (formerly called the "bulb") start to die first along with lower motor neurons.
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Purkinje cells also receive input from the inferior olivary nucleus on the contralateral side of the brainstem via climbing fibers. Although the inferior olive lies in the medulla oblongata and receives input from the spinal cord, brainstem and cerebral cortex, its output goes entirely to the cerebellum. A climbing fiber gives off collaterals to the deep cerebellar nuclei before entering the cerebellar cortex, where it splits into about 10 terminal branches, each of which gives input to a single Purkinje cell. In striking contrast to the 100,000-plus inputs from parallel fibers, each Purkinje cell receives input from exactly one climbing fiber; but this single fiber "climbs" the dendrites of the Purkinje cell, winding around them and making a total of up to 300 synapses as it goes.
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When the arterial blood pressure rises the arterioles are stimulated to dilate making it easier for blood to leave the arteries, thus deflating them, and bringing the blood pressure down, back to normal. At the same time the heart is stimulated via cholinergic parasympathetic nerves to beat more slowly (called bradycardia), ensuring that the inflow of blood into the arteries is reduced, thus adding to the reduction in pressure, and correction of the original error. Low pressure in the arteries, causes the opposite reflex of constriction of the arterioles, and a speeding up of the heart rate (called tachycardia). If the drop in blood pressure is very rapid or excessive, the medulla oblongata stimulates the adrenal medulla, via "preganglionic" sympathetic nerves, to secrete epinephrine (adrenaline) into the blood.
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Swallowing involves the coordinated contraction of more than 25 pairs of muscles in the oropharynx, larynx and esophagus, which are active during an oropharyngeal phase, followed by the primary esophageal peristalsis. Swallowing depends on a CPG located in the medulla oblongata, which involves several brain stem motor nuclei and two main groups of interneurons: a dorsal swallowing group (DSG) in the nucleus tractus solitarii and a ventral swallowing group (VSG) located in the ventrolateral medulla above the nucleus ambiguus. Neurons in the DSG are responsible for the generation of the swallowing pattern, while those in the VSG distribute the commands to the various motoneuronal pools. As in other CPGs, the functioning of the central network can be modulated by peripheral and central inputs, so that the swallowing pattern is adapted to the size of the bolus.
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Together the latter is known as the peripheral chemoreceptors which are situated in the aortic and carotid bodies. Information from all of these chemoreceptors is conveyed to the respiratory centers in the pons and medulla oblongata, which responds to deviations in the partial pressures of carbon dioxide and oxygen in the arterial blood from normal by adjusting the rate and depth of breathing, in such a way as to restore partial pressure of carbon dioxide back to 5.3 kPa (40 mm Hg), the pH to 7.4 and, to a lesser extent, the partial pressure of oxygen to 13 kPa (100 mm Hg). For instance, exercise increases the production of carbon dioxide by the active muscles. This carbon dioxide diffuses into the venous blood and ultimately raises the partial pressure of carbon dioxide in the arterial blood.
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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.
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The cranial root fibers arise from the cells of the nucleus ambiguus and emerge as four or five delicate rootlets from the side of the medulla oblongata, below the roots of the vagus. It runs lateralward to the jugular foramen, where it may interchange fibers with the spinal portion or even become united to it for a short distance; here it is also connected by one or two filaments with the jugular ganglion of the vagus. It then passes through the jugular foramen, separates from the spinal portion and is continued over the surface of the ganglion nodosum of the vagus, to the surface of which it is adherent, and is distributed principally to the pharyngeal and superior laryngeal branches of the vagus. Through the pharyngeal branch it probably supplies the Musculus uvulæ and Levator veli palatini.
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The sensory arm is composed of primary visceral sensory neurons found in the peripheral nervous system (PNS), in cranial sensory ganglia: the geniculate, petrosal and nodose ganglia, appended respectively to cranial nerves VII, IX and X. These sensory neurons monitor the levels of carbon dioxide, oxygen and sugar in the blood, arterial pressure and the chemical composition of the stomach and gut content. They also convey the sense of taste and smell, which, unlike most functions of the ANS, is a conscious perception. Blood oxygen and carbon dioxide are in fact directly sensed by the carotid body, a small collection of chemosensors at the bifurcation of the carotid artery, innervated by the petrosal (IXth) ganglion. Primary sensory neurons project (synapse) onto “second order” visceral sensory neurons located in the medulla oblongata, forming the nucleus of the solitary tract (nTS), that integrates all visceral information.
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Studies have found that regular meditation practice increases the protein BDNF in the brain and improves cellular health, reduces the rate of aging within cells, and a reduction of grey matter decay in the brain making it possible for higher neuroplasticity over longer periods of time. Meditation has been linked to higher levels of cognitive flexibility and a greater ability to recognize cognitive evaluations and functions. Recent studies suggest that meditation can increase the amount of gray matter in the medulla oblongata located in the brain stem leading to decreased arousal when dealing with unpleasant situations and higher levels of activity in the higher cortical regions of the brain and insula. Meditation has shown to increase activity in anterior cingulate cortex (ACC) and enhance communication from the anterior cingulate cortex to the rest of the brain resulting in a better ability to evaluate and resolve cognitive tasks.
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English anatomist Thomas Willis in 1664 first described the accessory nerve, choosing to use "accessory" (described in Latin as nervus accessorius) meaning in association with the vagus nerve. In 1848, Jones Quain described the nerve as the "spinal nerve accessory to the vagus", recognizing that while a minor component of the nerve joins with the larger vagus nerve, the majority of accessory nerve fibres originate in the spinal cord. In 1893 it was recognised that the heretofore named nerve fibres "accessory" to the vagus originated from the same nucleus in the medulla oblongata, and it came to pass that these fibres were increasingly viewed as part of the vagus nerve itself. Consequently, the term "accessory nerve" was and is increasingly used to denote only fibres from the spinal cord; the fact that only the spinal portion could be tested clinically lent weight to this opinion.
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Upon leaving the medulla oblongata between the olive and the inferior cerebellar peduncle, the vagus nerve extends through the jugular foramen, then passes into the carotid sheath between the internal carotid artery and the internal jugular vein down to the neck, chest, and abdomen, where it contributes to the innervation of the viscera, reaching all the way to the colon. Besides giving some output to various organs, the vagus nerve comprises between 80% and 90% of afferent nerves mostly conveying sensory information about the state of the body's organs to the central nervous system. The right and left vagus nerves descend from the cranial vault through the jugular foramina, penetrating the carotid sheath between the internal and external carotid arteries, then passing posterolateral to the common carotid artery. The cell bodies of visceral afferent fibers of the vagus nerve are located bilaterally in the inferior ganglion of the vagus nerve (nodose ganglia).
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This is very tightly controlled by the monitoring of the arterial blood gases (which accurately reflect composition of the alveolar air) by the aortic and carotid bodies, as well as by the blood gas and pH sensor on the anterior surface of the medulla oblongata in the brain. There are also oxygen and carbon dioxide sensors in the lungs, but they primarily determine the diameters of the bronchioles and pulmonary capillaries, and are therefore responsible for directing the flow of air and blood to different parts of the lungs. It is only as a result of accurately maintaining the composition of the 3 liters of alveolar air that with each breath some carbon dioxide is discharged into the atmosphere and some oxygen is taken up from the outside air. If more carbon dioxide than usual has been lost by a short period of hyperventilation, respiration will be slowed down or halted until the alveolar partial pressure of carbon dioxide has returned to 5.3 kPa (40 mmHg). It is therefore strictly speaking untrue that the primary function of the respiratory system is to rid the body of carbon dioxide “waste”.
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It implies that the planes of the brain are not necessarily the same as those of the body. However, the situation is more complex, since comparative embryology shows that the length axis of the neural tube (the primordium of the brain) has three internal bending points, namely two ventral bendings at the cervical and cephalic flexures (cervical flexure roughly between the medulla oblongata and the spinal cord, and cephalic flexure between the diencephalon and the midbrain), and a dorsal (pontine or rhombic flexure) at the midst of the hindbrain, behind the cerebellum. The latter flexure mainly appears in mammals and sauropsids (reptiles and birds), whereas the other two, and principally the cephalic flexure, appear in all vertebrates (the sum of the cervical and cephalic ventral flexures is the cause of the 90 degree angle mentioned above in humans between body axis and brain axis). This more realistic concept of the longitudinal structure of vertebrate brains implies that any section plane, except the sagittal plane, will intersect variably different parts of the same brain as the section series proceeds across it (relativity of actual sections with regard to topological morphological status in the ideal unbent neural tube).
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As calculated by the Henderson–Hasselbalch equation, in order to maintain a normal pH of 7.4 in the blood (whereby the pKa of carbonic acid is 6.1 at physiological temperature), a 20:1 bicarbonate to carbonic acid must constantly be maintained; this homeostasis is mainly mediated by pH sensors in the medulla oblongata of the brain and probably in the kidneys, linked via negative feedback loops to effectors in the respiratory and renal systems. In the blood of most animals, the bicarbonate buffer system is coupled to the lungs via respiratory compensation, the process by which the rate and/or depth of breathing changes to compensate for changes in the blood concentration of CO2. By Le Chatelier's principle, the release of CO2 from the lungs pushes the reaction above to the left, causing carbonic anhydrase to form CO2 until all excess acid is removed. Bicarbonate concentration is also further regulated by renal compensation, the process by which the kidneys regulate the concentration of bicarbonate ions by secreting H+ ions into the urine while, at the same time, reabsorbing HCO ions into the blood plasma, or vice versa, depending on whether the plasma pH is falling or rising, respectively.
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