74 Sentences With "air sac" | Random Sentence Generator

They'll bob their heads and nod before calls, or inflate one air sac but not the other.

Even after resorting to cheating by using my finger to push the air sac, I was getting nowhere.

Undaunted, a pelagic sea swallow appears to be feeding on a giant jelly's air sac, in this striking photo captured in Ponta Bay, Mozambique.

The machine is routinely used on premature newborns to keep the air sac in their underdeveloped lungs slightly inflated to prevent the sudden halt of breathing.

The little girl sustained "abrasions and a small injury" to her head, as well as facial bruising, a lacerated liver, fractured ribs and a ruptured air sac, the report states.

Image: Lindsey SwierkUnprecedented footage from Costa Rica shows tiny tropical lizards "breathing" from an air sac suspended atop their snouts—an apparent scuba tank that helps them stay submerged for extended periods.

What's more, I. prima had a bird-like cervical air sac and a neck with a high surface-to-volume ratio—characteristics that functioned like a built-in air conditioning system, allowing this oversized animal to stay cool.

As I worked my way through the accompanying app's Kegal exercise challenges, an inflated air sac nestled beneath my taint relayed the pressure change from my clenching and unclenching my pelvic floor to an electronic disk magnetically holstered in a receptacle on my hip.

A few months earlier, a team of researchers led by bioengineers Jordan Miller of Rice University and Kelly Stevens of the University of Washington (UW) with collaborators from UW, Duke University, Rowan University and the design firm Nervous System revealed a model of an air sac that mimicked the function of human lungs.

After her body was taken to a local medical center and checked by a medical examiner, however, it was determined there was bruising on the girl's head and face, a laceration on her liver, a few fractured ribs and a ruptured air sac, according to a police report obtained by NBC 6.

In 2016, Mark Hallett and Mathew Wedel for the first time reconstructed the entire air sac system of a sauropod, using B. altithorax as an example of how such a structure might have been formed. In their reconstruction a large abdominal air sac was located between the pelvis and the outer lung side. As with birds, three smaller sacs assisted the pumping process from the underside of the breast cavity: at the rear the posterior thoracic air sac, in the middle the anterior thoracic air sac and in front the clavicular air sac, in that order gradually diminishing in size. The cervical air sac was positioned under the shoulder blade, on top of the front lung.

Diagrams showing breathing motion (top two) and internal air sac system (bottom two) Pterosaur flight adaptations.

Most frogs use an air sac located under their mouth to produce mating calls. Air from the lungs channels to the air sac to inflate it, and the air sac resonates to produce a mating call. The larynx is larger and more developed in males, which causes their call to be louder and stronger In the túngara frog, males use a whining call followed by up to seven clucks. Males who have a whine-cluck call are more successful in attracting females than males whose call is a whine alone.

Frogs produce sound from the air sac below their mouth that from the outside, is seen to inflate and deflate. Air from the lungs is channeled to the air sac, which resonates to make the sound louder. The larynx is larger and more developed in males, though not significantly different from females. Frogs produce two types of calls that most experiments tend to focus on, which are release calling and mating calling.

Dorsal vertebrae of the holotype; the openings at their lower sides are , through which air sacs invaded the bone and connected with air cells inside The respiration system of sauropods, like that of birds, made use of air sacs. There was not a bidirectional airflow as with mammals, in which the lungs function as bellows, first inhaling and then exhaling air. Instead the air was sucked from the trachea into an abdominal air sac in the belly which then pumped it forward through the parabranchi, air loops, of the stiff lung. Valves prevented the air from flowing backward when the abdominal air sac filled itself again; at the same time a cervical air sac at the neck base sucked out the spent air from the lung.

The empty space between the pubic bones and the intestines has by G.S. Paul and David Martill been hypothesised to have been the location of a large air-sac. Dal Sasso & Maganuco however, rejected this interpretation because with living birds the air-sac of the posterior abdomen does not force the intestines forwards. They considered the space more likely to have been filled by a large yolk-sac. Air-sacs were nevertheless probable given the pneumatisation of the vertebrae.

The male also has as a bright orange or golden air sac on either side of his neck, which he inflates during mating displays. They have a lifespan of two to five years.

Bailey suggested similar humps for other dinosaurs with strongly elongated neural spines, such as Spinosaurus and Ouranosaurus. Artist's impression showing the speculative "skin sail", which was proposed in 1997 but now is considered unlikely by many scientists Daniela Schwarz and colleagues, in 2007, concluded that the bifurcated neural spines of diplodocids and dicraeosaurids enclosed an air sac, which would have been connected to the lungs as part of the respiratory system. In Dicraeosaurus, this air sac (the so-called supravertebral diverticulum) would have rested on top of the neural arch and filled the entire space between the spines. In Amargasaurus the upper two-thirds of the spines would have been covered by a sheath of keratin, restricting the air sac to the space between the lower one- third of the spines.

Ten different air sacs attach to the lungs to form areas for respiration. The most posterior air sacs (abdominal and post-thoracic) differ in that the right abdominal air sac is relatively small, lying to the right of the mesentery, and dorsally to the liver. While the left abdominal air sac is large and lies to the left of the mesentery. The connection from the main mesobronchi to the more anterior air sacs including the interclavicular, lateral clavicular, and pre-thoracic sacs known as the ventrobronchi region.

Birds have one of the most complex respiratory systems of all animal groups. Upon inhalation, 75% of the fresh air bypasses the lungs and flows directly into a posterior air sac which extends from the lungs and connects with air spaces in the bones and fills them with air. The other 25% of the air goes directly into the lungs. When the bird exhales, the used air flows out of the lungs and the stored fresh air from the posterior air sac is simultaneously forced into the lungs.

Diagrams of three different pterosaur genera, including an anhanguerid (bottom); notice the breathing motion (top two) and internal air sac system (bottom two) Pterosaur studies in 2009 showed that several pterosaurs, including ornithocheiromorphs, had a lung-and-air-sac system and a precisely controlled skeletal breathing pump, which supports a flow-through pulmonary ventilation model in pterosaurs, analogous to that of birds. This breathing method is also seen is carnivorous dinosaurs such as Aerosteon, but there are currently no studies showing its relationships with pterosaurs. A subcutaneous air sac system is present in at least some species of pterodactyloids, and this technique would have given a further reduced density to the living animal when breathing. Similar to modern crocodilians, many ornithocheiromorph genera appeared to have had some kind of hepatic piston, regarding their shoulder-pectoral girdles, which were suggested to be too inflexible to move the sternum.

Many saurischian dinosaurs possessed vertebrae and ribs that contained hollowed-out cavities (pneumatic foramina), which reduced the weight of the bones and may have served as a basic 'flow-through ventilation' system similar to that of modern birds. In such a system, the neck vertebrae and ribs are hollowed out by the cervical air sac; the upper back vertebrae, by the lung; and the lower back and sacral (hip) vertebrae, by the abdominal air sac. These organs constitute a complex and very efficient method of respiration. "Prosauropods" are the only major group of saurischians without an extensive system of pneumatic foramina.

A 2009 study showed that pterosaurs had a lung-and-air-sac system and a precisely controlled skeletal breathing pump, which supports a flow-through pulmonary ventilation model in pterosaurs, analogous to that of birds. The presence of a subcutaneous air sac system in at least some pterodactyloids would have further reduced the density of the living animal. Like modern crocodilians, pterosaurs appeared to have had a hepatic piston, seeing as their shoulder-pectoral girdles were too inflexible to move the sternum as in birds, and they possessed strong gastralia. Thus, their respiratory system had characteristics comparable to both modern archosaur clades.

Comparison between the air sacs of Majungasaurus and a modern bird Scientists have reconstructed the respiratory system of Majungasaurus based on a superbly preserved series of vertebrae (UA 8678) recovered from the Maevarano Formation. Most of these vertebrae and some of the ribs contained cavities (pneumatic foramina) that may have resulted from the infiltration of avian- style lungs and air sacs. In birds, the neck vertebrae and ribs are hollowed out by the cervical air sac, the upper back vertebrae by the lung, and the lower back and sacral (hip) vertebrae by the abdominal air sac. Similar features in Majungasaurus vertebrae imply the presence of these air sacs.

Heteropneustes, the airsac catfishes, is a genus of catfishes native to Asia. This genus is the only one in its family. Their bodies are elongated and compressed with greatly depressed heads. They have long air sac that serve as lungs that extends from the gill chamber.

The long bones are thin, hollow and very light. Air sac extensions from the lungs occupy the centre of some bones. The sternum is wide and usually has a keel and the caudal vertebrae are fused. There are no teeth and the narrow jaws are adapted into a horn-covered beak.

This could be similar to the way the relatively robust Apatosaurus weighs far more than the longer but much slimmer Diplodocus. In addition, it is possible that sauropods may have had an air sac system, like those in birds, which could reduce all sauropod mass estimates by 20% or more.

Advanced tetanurans would have possessed a sophisticated air-sac-ventilated lung system similar to birds, and an advanced circulatory system. In megalosaurids and allosaurids, the orientation of the femoral head is anteromedial such as in ceratosaurs, but in avetheropods this orientation is fully medial. Tetanuran locomotor morphology is relatively generalized, with few variations between taxa.

The loud calls of the male are heard over the summer months; harsh and high-pitched, these may reach 120 decibels. The sound is made by the rapid buckling of the timbal ribs, and amplified by resonation in an air sac; the frequency is around 4.3 kHz. Calls occur in the afternoon and dusk of warm days.

Sounds are generated by passing air from the bony nares through the phonic lips. These sounds are reflected by the dense concave bone of the cranium and an air sac at its base. The focused beam is modulated by a large fatty organ known as the 'melon'. This acts like an acoustic lens because it is composed of lipids of differing densities.

Vertebrae without pneumatopores would have indicated the boundaries between three air-sac systems: those of the neck base, the lungs, and the abdomen. The double rib heads would indicate a rather stiff thorax, ventilated by the gastralia. A system of hook-like uncinate processes on the ribs as with the Maniraptoriformes, allowing the ribcage to move flexibly, in articulation with an ossified sternum, was absent in Scipionyx.

A laryngocele is a congenital anomalous air sac communicating with the cavity of the larynx, which may bulge outward on the neck. It may also be acquired, as seen in glassblowers, due to continual forced expiration producing increased pressures in the larynx which leads to dilatation of the laryngeal ventricle (Sinus of Morgagni). It is also seen in people with chronic obstructive airway disease.

It is closely related to the dusky grouse (Dendragapus obscurus), and the two were previously considered a single species, the blue grouse. Adults have a long square tail, light gray at the end. Adult males are mainly dark with a yellow throat air sac surrounded by white, and a yellow wattle over the eye during display. Adult females are mottled brown with dark brown and white marks on the underparts.

The syrinx and sometimes a surrounding air sac resonate to sound waves that are made by membranes past which the bird forces air. The bird controls the pitch by changing the tension on the membranes and controls both pitch and volume by changing the force of exhalation. It can control the two sides of the trachea independently, which is how some species can produce two notes at once.

It was probably hollowed out by an outgrowth of an air sac in the nasal bone. Such a level of pneumatisation of the jugal is not known from other megalosaurids and might represent a separate autapomorphy. Cast of the lower jaw The lower jaw is rather robust. It is also straight in top view, without much expansion at the jaw tip, suggesting the lower jaws as a pair, the mandibula, were narrow.

Old males, in particular, become nearly pink. Because skin blood vessels constrict in cold water, the walrus can appear almost white when swimming. As a secondary sexual characteristic, males also acquire significant nodules, called "bosses", particularly around the neck and shoulders. Native Alaskan woman dresses walrus skin The walrus has an air sac under its throat which acts like a flotation bubble and allows it to bob vertically in the water and sleep.

Though not having the form of a true rosette because the jaw ends were not expanded, the intermeshing front teeth functioned as a "prey grab" to catch slippery animals; the describers therefore consider Guidraco to have been a fish-eater. The neck vertebrae are moderately elongated, keeled and possess large pneumatic openings on their sides, the access by which the air sac of the neck could enter their hollow interiors. The axis bears a spiked spine.

The inside of the lower jaws also bore a complex series of ridges and toothlike processes, as well as a pair of horizontal, shelf-like structures. Furthermore, the jaws were unusual in being hollow and air filled, apparently being connected to the air sac system. Caenagnathids also tended to be more lightly built than the oviraptorids. They had slender arms and long, gracile legs, although they lacked the extreme cursorial specializations seen in avimimids and Caudipteryx.

Adults have a long square tail, gray at the end. Adult males are mainly dark with a purplish throat air sac surrounded by white, and a yellow to red wattle over the eye during display. Adult females are mottled brown with dark brown and white marks on the underparts. Their breeding habitat is the edges of conifer and mixed forests in mountainous regions of western North America, from southeastern Alaska and Yukon south to New Mexico.

Also, Odontoptila is already used for a geometer moth genus: ICZN (1999), uBio (2005) – from the Paleocene-Eocene boundary of Morocco – is the smallest pseudotooth bird discovered to date and was just a bit larger than a white- chinned petrel (Procellaria aequinoctialis).Scarlett (1972), Olson (1985: pp. 199–200), Bourdon (2005, 2006), Mayr (2008, 2009: pp. 57,59), Mayr et al. (2008) The Pelagornithidae had extremely thin-walled bones widely pneumatized with the air sac extensions of the lungs.

In any case a diaphragm itself or its position could not be directly observed. Many bird livers are large too, showing that such a trait is compatible with an air-sac system. The small body cavity in front of the halo seemed to indicate the presence of small stiff bird-like lungs. The presumed M. diaphragmaticus was shown to be an artifact caused by the polishing and engraving of calcite nodules of non-organic origin during preparation, creating the illusion of muscle fibres.

When a chick becomes too large to absorb oxygen through the pores of its eggshell, it uses its egg tooth to peck a hole in the air sac located at the flat end of the egg. This sac provides a few hours' worth of air, during which the chick breaks through the eggshell to the outside. The egg tooth falls off several days after hatching. Kiwis lack an egg tooth, instead using their legs and beak to break through a relatively thin eggshell.

Tympanal organs are hearing organs. Such an organ is generally a membrane (tympanum) stretched across a frame backed by an air sac and associated sensory neurons. In the order Coleoptera, tympanal organs have been described in at least two families. Several species of the genus Cicindela in the family Cicindelidae have ears on the dorsal surface of the first abdominal segment beneath the wing; two tribes in the family Dynastinae (Scarabaeidae) have ears just beneath the pronotal shield or neck membrane.

Such values are among the highest recorded for any terrestrial mammal, and a relatively extreme example of ultrasonic communication. For Philippine tarsiers, ultrasonic vocalizations might represent a private channel of communication that subverts detection by predators, prey and competitors, enhances energetic efficiency, or improves detection against low-frequency background noise. Male howler monkeys are among the loudest land mammals and their roars can be heard up to . Roars are produced by modified larynx and enlarged hyoid bone which contains an air sac.

These intermolecular forces put great restraint on the inner walls of the air sac, tighten the surface all together, and unyielding to stretch for inhalation. Thus, without something to alleviate this surface tension, alveoli can collapse and cannot be filled up again. Surfactant is essential mixture that is released into the air-facing surface of inner walls of air sacs to lessen the strength of surface tension. This mixture inserts itself among water molecules and breaks up hydrogen bonds that hold the tension.

Adult males are mainly dark (especially sooty grouse) with a yellow (sooty grouse) or purplish (dusky grouse) throat air sac surrounded by white, and a yellow (sooty grouse) or yellow-to-red (dusky grouse) wattle over the eye during display. Adult females of both species are mottled brown with dark brown and white marks on the underparts. Their breeding habitat is the edges of conifer and mixed forests in mountainous regions of North America and Eurasia. Their range is closely associated with that of various conifers.

123 The holotype of Mirischia is notable for having asymmetrical ischia. Quoting from Naish et al. (2004): "The ischia of Mirischia are asymmetrical, that on the left being perforated by an oval foramen while that on the right has an open notch in the same position." The specimen is also unusual in that it preserves some soft tissue remains: apart from the intestine, what the describers interpreted to have been an air sac was preserved between its pubic and ischial bones in the form of a vacuity.

There are many different mechanisms to produce mating calls, which can be broadly categorized into vocalizations and mechanical calls. Vocalizations are considered as sounds produced by the larynx and are often seen in species of birds, mammals, amphibians, and insects. Mechanical calls refer to any other type of sound that the animal produces using unique body parts and/or tools for communication with potential mates. Examples include crickets that vibrate their wings, birds that flap their feathers, and frogs that use an air sac instead of lungs.

Humidity is also important because the rate at which eggs lose water by evaporation depends on the ambient relative humidity. Evaporation can be assessed by candling, to view the size of the air sac, or by measuring weight loss. Relative humidity should be increased to around 70% in the last three days of incubation to keep the membrane around the hatching chick from drying out after the chick cracks the shell. Lower humidity is usual in the first 18 days to ensure adequate evaporation.

Only the spines of Amargasaurus were similarly elongated. The spines of Amargasaurus led to much speculation about their possible life appearance and function. As hypothesised by separate authors, they could have supported a sail or horny sheaths, and could have been used for display, defense, or thermoregulation. Daniela Schwarz and colleagues, in 2007, found that the double-row formed by the bifurcated neural spines along the spine of dicraeosaurids would have enclosed an air sac, the so-called supravertebral diverticulum, that would have been connected to the lungs as part of the respiratory system.

Male treefrog (Dendropsophus microcephalus) inflating his air sac as he calls The calls made by caecilians and salamanders are limited to occasional soft squeaks, grunts or hisses and have not been much studied. A clicking sound sometimes produced by caecilians may be a means of orientation, as in bats, or a form of communication. Most salamanders are considered voiceless, but the California giant salamander (Dicamptodon ensatus) has vocal cords and can produce a rattling or barking sound. Some species of salamander emit a quiet squeak or yelp if attacked.

Sarcoptic mites feed by burrowing within the living layers of the epidermis, mainly stratum spinosum. Demodectic mites feed in a position technically external to the skin, between the epidermis and the hair shaft in hair follicles. Dermanyssid and trombiculid mites feed whilst external to the skin by piercing the skin with, respectively, their chelicerae or a stylostome feeding tube. Mites at other sites feed by using their chelicerae to scrape either at the skin surface, or at base of feather, or to penetrate and scrape at internal tissue such as air-sac or lung.

In 2010 Gregory S. Paul estimated a length of 8 m (26 ft) and a weight of 2.5 tonnes (2.75 short tons). In 2016 Molina-Pérez and Larramendi gave a length of 9 m (29.5 ft) and a weight of 3.3 tonnes (3.6 short tons). Bistahieversor differs from other tyrannosaurs in the possession of 64 teeth, an extra opening above the eye, and a keel along the lower jaw. The opening above the eye is thought to have accommodated an air sac that would have lightened the skull's weight.

Shared tetanuran features include a ribcage indicating a sophisticated air-sac-ventilated lung system similar to that in modern birds. This character would have been accompanied by an advanced circulatory system. Other tetanuran characterizing features include the absence of the fourth digit of the hand, placement of the maxillary teeth anterior to the orbit, a strap-like scapula, maxillary fenestrae, and stiffened tails. During the Late Jurassic and Early Cretaceous, large spinosaurids and allosaurs flourished but possibly died out in the northern hemisphere before the end of the Cretaceous, and were replaced as apex predators by tyrannosauroid coelurosaurs.

In Weinbaum's Solar System, in keeping with the then-current "near- collision" hypothesis of planetary formation, Jupiter radiates enough heat to create Earth-like environments on the Galilean moons. Europa is airless except for a depression on the Jupiter-facing side of the tidally locked moon, which holds a thin, but breathable atmosphere. This region is divided into a number of small valleys separated from each other by ridges rising above the atmosphere. The most widespread Europan species is the bladder bird, which carries its own air supply with it in an air sac, allowing it to cross over the airless peaks.

The cytoneme-mediated model suggests that Dpp is directly transported to target cells via actin-based filopodia called cytonemes that extend from the apical surface of Dpp- responding cells to the Dpp-producing source cells. These cytonemes have been observed, but the dependence of the Dpp gradient on cytonemes has not been definitively proven in imaginal wing discs. However, Dpp is known to be required for and sufficient to extend and maintain cytonemes. Experiments analyzing the dynamics between Dpp and cytonemes have been conducted in the air sac primordium, where Dpp signaling was found to have a functional link with cytonemes.

Stereo images of the furculae of A. riocoloradense (A) and the Magpie-goose, Anseranas semipalmata (B). Scale bars are 10 cm in (A) and 2 cm in (B). Some of Aerosteon's bones show pneumatisation (air-filled spaces), including pneumatic hollowing of the furcula and ilium, and pneumatisation of several gastralia, suggesting that it may have had a respiratory air-sac system similar to that of modern birds. These air sacs would have acted like bellows, moving air into and out of the animal's relatively inflexible lungs, instead of the lungs themselves being expanded and contracted as occurs with mammals.

Uniquely among troodontids, the postorbital bone is slender and radiates into three processes. Like Zanabazar, there is a pneumatic diverticulum in the jugal bone where an air sac was present within the bone; there is also a pneumatic opening on the rear side of the quadrate bone, as in other troodontids. Unlike Sauronithoides, Zanabazar, and Stenonychosaurus, the crest separating the parietal bones does not participate in the border of the supratemporal (upper) temporal fenestra at the back of the skull. Characteristic of troodontids, Liaoningvenator has a pitted groove on the outer edge of its shallow and triangular lower jaw.

Many of the particles passed through the model lung into the blood channel, and mechanical breathing was found to greatly enhance nanoparticle absorption from the air sac into the blood. The Wyss Institute team is working to build other organ models, such as a gut-on-a-chip, as well as bone marrow and even cancer models. They are exploring the potential for combining organ systems, such as linking a breathing lung-on-a-chip to a beating heart-on-a-chip. The engineered organ combination could be used to test inhaled drugs and to identify new and more effective therapeutics that lack adverse cardiac side effects.

Tympanal organ on the tibia of the katydid Zabalius aridus Tympanal organ of two species of moths, ventral view of abdomen (Tineidae and Pyralidae) A tympanal organ (or tympanic organ) is a hearing organ in insects, consisting of a membrane (tympanum) stretched across a frame backed by an air sac and associated sensory neurons. Sounds vibrate the membrane, and the vibrations are sensed by a chordotonal organ. Hymenoptera (bees, wasps, ants, etc.) do not have a tympanal organ, but they do have a Johnston's organ. Tympanal organs occur in just about any part of the insect: the thorax, the base of the wing, the abdomen, the legs, etc.

In Dicraeosaurus, this air sac would have occupied the entire space between the left and right parts of the spines, while it would have been restricted to the lower third of the spines in Amargasaurus. The upper two thirds would likely have been covered by a horny sheath, as is indicated by longitudinal striations on their surface. Gallina and colleagues, in 2019, considered this the most reasonable interpretation that may likewise be applied to Bajadasaurus. These researchers further argued that horn is more resistant to impact-related fractures than bone, and that a horny sheath would therefore have protected the delicate spines from damage.

Although Spanky would like to play football with the rest of the gang, he is stuck at home taking care of his baby sister. Hoping to lull the kid to sleep, thereby allowing himself to sneak out of the house, Spanky tries all sorts of "sure-fire" beddie-bye methods. But neither he nor his co-conspirator "Alfalfa" are able to coerce the little brat into drifting off to dreamland—though they do briefly fall asleep themselves. Their efforts finally fail when, in the process of inflating the football, they cause its air sac to burst loudly, waking the baby and ruining all their efforts.

Pneumatoraptor differs from other theropods in having a narrow shoulder blade that is nearly circular in cross section, as well as having a large opening in the bone to house a hollow air sac cavity. The bone is small, indicating that the animal was only about half the size of the related Sinornithosaurus or 0.73 m (2.2 ft). The shoulder girdle is L-shaped, showing it to be a member of the group Paraves, which also includes the dromaeosaurids, troodontids, and birds. While the Pneumatoraptor remains are too incomplete to tell which, if any, of these specific groups it belongs to, many of the bones features are similar to dromaeosaurids.

The term air mattress may also refer to a certain inflatable swimming pool or beach toy, which has an air-sac "pillow" and several (usually four or five) tubes running its length. Also called a "lilo" (UK, AUS, NZ), "pool air mat", "air mat", "pool lounge", or "float(ing) mat(tress)", it is used to recline on the water surface. The Li-Lo trademark for a rubberised material products was registered in UK on 19 Apr 1944 and in the USA on 25 Sep 1947 by P. B. Cow and Co Ltd. An inflatable air mattress for recreational use was advertised as one of the Li-Lo brand of products at the British Industries Fair in London 1949.

Gogrol returns because he needs one of them to pilot the ship to one of the human settlements on Io. He shoots Sands in the leg and abducts Avery; when she passes out on top of the ridge, he picks her up and carries her, then tosses his pistol down to Sands with one shot left, so Sands can commit suicide. Instead, Sands shoots a native bladder bird and uses its air sac to keep breathing as he gives chase. He catches up to Gogrol in the darkened spaceship control room, finally recognizing him as Kratska. Sands sends Avery outside to retrieve Coretti; Kratska chooses that moment to attack Sands, but Sands manages to kill Kratska before passing out.

American toad, (Anaxyrus americanus) singing Frogs are much more vocal, especially during the breeding season when they use their voices to attract mates. The presence of a particular species in an area may be more easily discerned by its characteristic call than by a fleeting glimpse of the animal itself. In most species, the sound is produced by expelling air from the lungs over the vocal cords into an air sac or sacs in the throat or at the corner of the mouth. This may distend like a balloon and acts as a resonator, helping to transfer the sound to the atmosphere, or the water at times when the animal is submerged.

The male Mongolian gazelle and musk ox possess an air space (paired and two-chambered in the former) attached to the larynx, while bears have such spaces connected to the pharynx. Male howler monkeys have an unpaired rostroventral laryngeal air sac within the hyoid bulla (extension of the hyoid bone) and a pair of ventral laryngeal air spaces outside. The hammer-headed bat has a pouch in the palatine that connects to an enlarged nasopharynx region, in addition to paired cheek pouches which extend to the rostrum. Elephants possess a pharyngeal pouch associated with their larynx and hyoid apparatus, and their roars can also be modified by the nostrils in their trunks.

To attract a mate, fireflies (Lampyridae) use modified fat body cells with transparent surfaces backed with reflective uric acid crystals to produce light by bioluminescence. Light production is highly efficient, by oxidation of luciferin catalyzed by enzymes (luciferases) in the presence of adenosine triphosphate (ATP) and oxygen, producing oxyluciferin, carbon dioxide, and light. Tympanal organs or hearing organs consist of a membrane (tympanum) stretched across a frame backed by an air sac and associated sensory neurons, are found in two families. Several species of the genus Cicindela (Carabidae) have hearing organs on the dorsal surfaces of their first abdominal segments beneath the wings; two tribes in the Dynastinae (within the Scarabaeidae) have hearing organs just beneath their pronotal shields or neck membranes.

The response of the lung-on-a-chip to inhaled living pathogens was tested by introducing E. Coli bacteria into the air channel on the lung air sac side of the device, while flowing white blood cells through the channel on the blood vessel side. The lung cells detected the bacteria and, through the porous membrane, activated the blood vessel cells, which in turn triggered an immune response that ultimately caused the white blood cells to move to the air chamber and destroy the bacteria. Researchers also introduced a variety of nanoscale particles (such as those found in commercial products, and in air and water pollution) into the air channel. Several types of these nanoparticles entered the lung cells and caused the cells to overproduce free radicals and to induce inflammation.

Hone, Naish, and Cuthill suggested that the wing membranes and air-sac system would have been more effective at controlling heat than a crest, and wind and water could also have helped cool pterosaurs in high-temperature maritime settings. In 2013, Witton agreed that the substantially larger crests of adult thalassodromids indicated that they were more important for behavioural activities than for physiology. He found the idea that the crests were used for thermoregulation problematic, since they did not grow regularly with body size; they grew at a fast pace in near-adults, quicker than what would be predicted for the growth of a thermoregulatory structure. According to Witton, the large, highly vascular wing membranes of pterosaurs would provide the surface area needed for thermoregulation, meaning the crests were not needed for that function.

In waterslager canaries, which produce most syllables using the left syrinx, as soon as a unilaterally produced syllable finishes, the right side opens briefly to allow inspiratory airflow through both bronchi before being closed again for left syrinx song production. During this “mini- breath” the left side may remain partially or fully adducted, allowing less inspiratory airflow than the right side while remaining ready to quickly resume singing. When bilateral airflow and subsyringeal air sac pressure were monitored along with electromyographic activity of expiratory abdominal muscles in brown thrashers (Toxostoma rufum), it was observed that during unilateral production of song, expiratory abdominal muscle activity was the same on both sides. This indicates that while inspiration and syringeal song control may be lateralized, motor control of respiratory muscles possibly remains bilateral.

A brown pelican opening mouth and inflating air sac to display tongue and some inner bill anatomy American white pelican with knob which develops on bill before the breeding season An adult brown pelican with a chick in a nest in Chesapeake Bay, Maryland, US: This species will nest on the ground when no suitable trees are available. Australian pelican displaying the extent of its throat pouch (Lakes Entrance, Victoria). Pelicans are very large birds with very long bills characterised by a downcurved hook at the end of the upper mandible, and the attachment of a huge gular pouch to the lower. The slender rami of the lower bill and the flexible tongue muscles form the pouch into a basket for catching fish, and sometimes rainwater, though not to hinder the swallowing of large fish, the tongue itself is tiny.

An air-sac system connected to the spaces not only lightened the long necks, but effectively increased the airflow through the trachea, helping the creatures to breathe in enough air. By evolving vertebrae consisting of 60% air, the sauropods were able to minimize the amount of dense, heavy bone without sacrificing the ability to take sufficiently large breaths to fuel the entire body with oxygen. According to Kent Stevens, computer-modeled reconstructions of the skeletons made from the vertebrae indicate that sauropod necks were capable of sweeping out large feeding areas without needing to move their bodies, but were unable to be retracted to a position much above the shoulders for exploring the area or reaching higher. Another proposed function of the sauropods’ long necks was essentially a radiator to deal with the extreme amount of heat produced from their large body mass.