A nostril (or naris /ˈnɛərɪs/, plural nares /ˈnɛəriːz/) is one of the two channels of the nose, from the point where they bifurcate to the external opening. In birds and mammals, they contain branched bones or cartilages called turbinates, whose function is to warm air on inhalation and remove moisture on exhalation. Fish do not breathe through their noses, but they do have two small holes used for smelling, which may, indeed, be called nostrils.

In humans, the nasal cycle is the normal ultradian cycle of each nostril's blood vessels becoming engorged in swelling, then shrinking.

The nostrils are separated by the septum. The septum can sometimes be deviated, causing one nostril to appear larger than the other. With extreme damage to the septum and columella, the two nostrils are no longer separated and form a single larger external opening.

Like other tetrapods, humans have two external nostrils (anterior nares) and two additional nostrils at the back of the nasal cavity, inside the head (posterior nares, posterior nasal apertures or choanae). Each choana contains approximately 1000 strands of nasal hair. They also connect the nose to the throat (the nasopharynx), aiding in respiration. Though all four nostrils were on the outside the head of our fish ancestors, the nostrils for outgoing water (excurrent nostrils) migrated to the inside of the mouth, as evidenced by the discovery of Kenichthys campbelli, a 395-million-year-old fossilized fish which shows this migration in progress. It has two nostrils between its front teeth, similar to human embryos at an early stage. If these fail to join up, the result is a cleft palate.[1]

It is possible for humans to smell different olfactory inputs in the two nostrils and experience a perceptual rivalry akin to that of binocular rivalry when there are two different inputs to the two eyes.[2]

The Procellariiformes are distinguished from other birds by having tubular extensions of their nostrils.

Human Nostrils 01
A woman's nostrils
Part ofNose
SystemOlfactory system
Anatomical terminology

See also


  1. ^ Lloyd, John; Mitchinson, John (2008). The Book of General Ignorance. London: Faber and Faber. pp. 2, 299. ISBN 978-0-571-24139-2. OCLC 191753333. Retrieved 16 July 2011.
  2. ^ Zhou, Wen; Chen, Denise (29 September 2009). "Binaral rivalry between the nostrils and in the cortex". Current Biology. 19 (18): 1561–5. doi:10.1016/j.cub.2009.07.052. PMC 2901510. PMID 19699095. Retrieved 1 May 2012.

External links

Black-nostril false moray

The black-nostril false moray, blacknose false moray or blacknose reef eel (Kaupichthys atronasus), is an eel in the family Chlopsidae. It was described by Leonard Peter Schultz in 1953. It is a tropical, marine eel which is known from throughout the Indo-Pacific, including the Chagos Islands, Samoa, the Ryukyu Islands, the southern Great Barrier Reef, and Micronesia. It typically dwells in coral reefs at depths greater than 14 m. They can reach a maximum total length of 12 cm (4.7 in).The black-nostril false moray is considered an uncommon species.

Blowhole (anatomy)

In cetology, the study of whales and other cetaceans, a blowhole is the hole at the top of the head through which the animal breathes air. In baleen whales, these are in pairs. It is homologous with the nostril of other mammals, and evolved via gradual movement of the nostrils to the top of the head. As whales reach the water surface to breathe, they forcefully expel air through the blowhole. The exhalation is released into the comparably lower-pressure, colder atmosphere, and any water vapor condenses. This spray, known as the blow, is often visible from far away as a white splash, which can also be caused by water resting on top of the blowhole.

Air sacs just below the blowhole allow whales to produce sounds for communication and, for toothed whales, echolocation. These air sacs are filled with air, which is then released again to produce sound in a similar fashion to releasing air from a balloon. When whales dive under water their nasal plug covers the nasal passage to the blowhole. The muscles controlling the nasal plug are relaxed during this time, but when the whale comes up for air these muscles contract and allow for the blowhole to be opened and the process of exhalation and inhalation to occur.

Baleen whales have two blowholes positioned in a V-shape while toothed whales have only one blowhole. The blowhole of a sperm whale, a toothed whale, is located left of centre in the frontal area of the snout, and is actually its left nostril, while the right nostril lacks an opening to the surface and its nasal passage is otherwise well developed.

The trachea only connects to the blowhole, and the animal cannot breathe through its mouth. Because of this, there is no risk of food accidentally ending up in the animal's lungs, so whales have no gag reflex.

Captain Underpants and the Big, Bad Battle of the Bionic Booger Boy

Captain Underpants and the Big, Bad Battle of the Bionic Booger Boy are the sixth and seventh books in the Captain Underpants series by Dav Pilkey. The first part was published on August 1, 2003, and the second part was published on September 30, 2003. The duology features the debut of George and Harold's new pets Sulu (a hamster with a bionic endoskeleton) and Crackers (a Quetzalcoatlus) who first appeared in the first and second parts respectively. The second part also features the debut of time travel in the series, which would become a core theme of the series later on. The full color covers will be for Part 1's color called Purple and Blue. but Part 2's color called, Yellow and White.


The choana (plural choanae), posterior nasal aperture or internal nostril is one of two openings found at the back of the nasal passage between the nasal cavity and the throat in tetrapods with secondary palates, including humans and other mammals (as well as crocodilians and most skinks).

In animals with secondary palates, they allow breathing when the mouth is closed. In tetrapods without secondary palates their function relates primarily to olfaction (sense of smell).

The choanae are separated in two by the vomer.

Dilator naris muscle

The dilator naris muscle is a part of the nasalis muscle. It is divided into posterior and anterior parts.

The dilator naris posterior is placed partly beneath the levator labii superioris. It arises from the margin of the nasal notch of the maxilla, and from the lesser alar cartilages, and is inserted into the skin near the margin of the nostril.

The dilator naris anterior is a delicate fasciculus, passing from the greater alar cartilage to the integument near the margin of the nostril; it is situated in front of the dilatator naris posterior muscle.


The Ichthyosauriformes are a group of marine reptiles, belonging to the Ichthyosauromorpha, that lived during the Mesozoic.

The stem clade Ichthyosauriformes was in 2014 defined by Ryosuke Motani and colleagues as the group consisting of all ichthyosauromorphs that are more closely related to Ichthyosaurus communis than to Hupehsuchus nanchangensis. Their synapomorphies include the possession of a long nasal bone, stretching to the front beyond the nostril; large scleral rings, filling the eye sockets; a narrow snout in top view; and converging digits with little space between them.

The Ichthyosauriformes probably split off in the Early Triassic, about 250 million years ago; the last known forms lived in the middle Cretaceous. A basal ichthyosauriform is Cartorhynchus; more derived species are part of the Ichthyopterygia which again include the Ichthyosauria.


A kalaleng is a nose flute made from bamboo from the Philippines.

Usually around two feet in length a kalaleng has holes cut in the side, to be stopped by the fingers producing the notes. The player closes one nostril with a bit of cotton, then forces the air from the other into a small hole cut in the end of the tube. This instrument is found mostly in the northern Philippines and is popular with all the native mountain population of the area. It is a usually decorated with etched patterns.

The instrument is popular with men and is often used in courting.


Latirhinus (meaning "broad nose" from the Latin latus (broad) and Greek ῥίς, rhis (nose)) is an extinct genus of saurolophine hadrosaurid dinosaur from the Late Cretaceous of Mexico. The type species, Latirhinus uitstlani, was named in 2012 on the basis of a partial skeleton from the Campanian-age Cerro del Pueblo Formation. The specific name uitstlani means "southern" in the Náhuatl language of Mexico, a reference to the species' southern occurrence in the Cretaceous landmass Laramidia. Latirhinus is characterised by its large, arched nasal bones above the snout and larger narial or nostril openings. It is most similar to the saurolophine Gryposaurus.

Levator labii superioris alaeque nasi muscle

The levator labii superioris alaeque nasi muscle is, translated from Latin, the "lifter of both the upper lip and of the wing of the nose". It has the longest name of any muscle in an animal. The muscle is attached to the upper frontal process of the maxilla and inserts into the skin of the lateral part of the nostril and upper lip.

Major alar cartilage

The major alar cartilage (greater alar cartilage) (lower lateral cartilage) is a thin, flexible plate, situated immediately below the lateral nasal cartilage, and bent upon itself in such a manner as to form the medial wall and lateral wall of the nostril of its own side.

The portion which forms the medial wall (crus mediale) is loosely connected with the corresponding portion of the opposite cartilage, the two forming, together with the thickened integument and subjacent tissue, the nasal septum.

The part which forms the lateral wall (crus laterale) is curved to correspond with the ala of the nose; it is oval and flattened, narrow behind, where it is connected with the frontal process of the maxilla by a tough fibrous membrane, in which are found three or four small cartilaginous plates, the lesser alar cartilages (cartilagines alares minores; sesamoid cartilages).

Above, it is connected by fibrous tissue to the lateral cartilage and front part of the cartilage of the septum; below, it falls short of the margin of the nostril, the ala being completed by fatty and fibrous tissue covered by skin.

In front, the greater alar cartilages are separated by a notch which corresponds with the apex of the nose.


The Monofenestrata are an unranked group of pterosaurs that includes the family Wukongopteridae and the suborder Pterodactyloidea.The clade Monofenestrata was in 2009/2010 defined as the group consisting of Pterodactylus and all species sharing with Pterodactylus the synapomorphy, shared derived trait, of an external nostril confluent with the antorbital fenestra, the major skull opening on the side of the snout. The name is derived from Greek monos, "single", and Latin fenestra, "window". The concept was inspired by the discovery of Darwinopterus, a species combining a pterodactyloid-type skull with a more basal build of the remainder of the body. The Darwinoptera, a primitive subgroup of monofenestratans showing this transitional anatomy, was also named for Darwinopterus and defined as all descendants of its common ancestor with Pterorhynchus.The earliest known monofenestrate fossils have been found in the Stonesfield Slate formation of the United Kingdom, which dates to the Bathonian stage of the Middle Jurassic, dated to about 166 million years ago. Identified elements include cervical vertebrae, fourth metacarpals and a possible pterodactyloid synsacrum. Below is a cladogram showing the results of a phylogenetic analysis presented by Andres, Clark & Xu, 2014. This study found the two traditional groupings of ctenochasmatoids and kin as an early branching group, with all other pterodactyloids grouped into the Eupterodactyloidea.

Nose piercing

Nose piercing is the piercing of the skin or cartilage which forms any part of the nose, normally for the purpose of wearing jewelry, called a nose-jewel. Among the different varieties of nose piercings, the nostril piercing is the most common. Nose piercing is the third most common variety of piercing after earlobe piercing and tongue piercing.


Ophidioidei is one of two suborders in the order Ophidiiformes, the cusk eels, viviparous brotulas and pearlfishes. The main distinction from the suborder Bythitoidei is that the Ophidioidei are oviparous, other features include having a caudal fin which is joined to both the anal fin and the dorsal fin forming an even combined fin which tapers to a point, a lack of an external intromittent organ in males and the anterior nostril is placed high above the mouth.


Phenylephrine is a medication primarily used as a decongestant, to dilate the pupil, to increase blood pressure, and to relieve hemorrhoids. While marketed as a decongestant, taken by mouth at recommended doses it is of unclear benefit for hay fever. It can be taken by mouth, given by injection into a vein or muscle, or applied to the skin.Common side effects when taken by mouth or injected include nausea, headache, and anxiety. Use on hemorrhoids is generally well tolerated. Severe side effects may include a slow heart rate, intestinal ischemia, chest pain, kidney failure, and tissue death at the site of injection. It is unclear if use during pregnancy or breastfeeding is safe. Phenylephrine is a selective α1-adrenergic receptor activator which results in the constriction of both arteries and veins.Phenylephrine was patented in 1927 and came into medical use in 1938. It is available as a generic medication. In the United Kingdom the injectable formulation costs the NHS 4 pounds a vial. Unlike pseudoephedrine, abuse of phenylephrine is very uncommon.

Pit viper

The Crotalinae, commonly known as pit vipers, crotaline snakes (named for the Ancient Greek: κρόταλον krotalon castanet/rattle of a rattlesnake's tail), or pit adders, are a subfamily of venomous vipers found in Eurasia and the Americas. They are distinguished by the presence of a heat-sensing pit organ located between the eye and the nostril on both sides of the head. Currently, 18 genera and 151 species are recognized: seven genera and 54 species in the Old World, against a greater diversity of 11 genera and 97 species in the New World. These are also the only viperids found in the Americas. The groups of snakes represented here include rattlesnakes, lanceheads, and Asian pit vipers. The type genus for this subfamily is Crotalus, of which the type species is the timber rattlesnake, C. horridus.These snakes range in size from the diminutive hump-nosed viper, Hypnale hypnale, that grows to an average total length (including tail) of only 30–45 cm (12–18 in), to the bushmaster, Lachesis muta, a species known to reach a maximum total length of 3.65 m (12.0 ft) in length.

What makes this subfamily unique is that all member species share a common characteristic: a deep pit, or fossa, in the loreal area between the eye and the nostril on either side of the head. These loreal pits are the external openings to a pair of extremely sensitive infrared-detecting organs, which in effect give the snakes a sixth sense to help them find and perhaps even judge the size of the small, warm-blooded prey on which they feed.Osine triphosphate, monoamine oxidase, generalized esterases and acetylcholine esterase have also been found in it. When prey comes into range, infrared radiation falling onto the membrane allows the snake to determine its direction. Experiments have shown, when deprived of their senses of sight and smell, these snakes can strike accurately at moving objects less than 0.2 °C (0.36 °F) warmer than the background. The paired pit organs provide the snake with thermal rangefinder capabilities. These organs are of great value to a predator that hunts at night, as well as for avoiding the snake’s own predators.Among vipers, these snakes are also unique in that they have a specialized muscle, called the muscularis pterigoidius glandulae, between the venom gland and the head of the ectopterygoid. Contraction of this muscle, together with that of the m. compressor glandulae, forces venom out of the gland.


Rhinomanometry is a form of manometry used in evaluation of the nasal cavity.

Rhinomanometry is a standard diagnostic tool aiming to objectively evaluate the respiratory function of the nose. It measures pressure and flow during normal inspiration and expiration through the nose. Increased pressure during respiration is a result of increased resistance to airflow through nasal passages (nasal blockage), while increased flow, which means the speed of airstream, is related to better patency. Nasal obstruction leads to increased values of nasal resistance. Rhinomanometry may be used to measure only one nostril at a time (anterior rhinomanometry) or both nostrils simultaneously (posterior rhinomanometry).

In anterior rhinomanometry, the patient is asked to blow his nose, sit in an upright position, and the pressure sensing tube is placed in one nostril while the contralateral nostril is left opened. The patient places a mask which is connected to the device tightly onto his face. Unilateral measurements are performed to detect any asymmetry or abnormality in nasal airway resistance. When the measurements are performed before and after the application of a nasal decongestant spray, the differences in resistance can be attributed to nasal mucosal congestion. If there is no significant improvement after decongestant, anatomical abnormality, like deformity of cartilage or bone within nasal cavity is suspected. However, such measurements allow only to detect in which side of the nose there is obstruction, not the location within the nasal cavity, which can be detected by acoustic rhinometry or endoscopy.

Anterior rhinomanometry is more commonly used and it is often recommended for its easy technique. However, it should be stressed that controlled ambient temperature and humidity, tight seal of the facial mask, contralateral nostril closure and prevention of mouth breathing are essential for reproducible results. Patients' complaints of nasal obstruction are not always confirmed by these objective measurements. Posterior rhinomanometry should be done by more experienced technicians and very good collaboration of the patient is essential.

Rhinomanometry can be used to test nasal patency in basal conditions in order to differentiate between anatomical and mucosal abnormalities by performing a test with a decongestant. It can also be used to check impact of other treatments, like nasal steroid sprays, on objective nasal blockage. It is also used in challenge tests with allergen when nasal patency is measured before and after application of allergen onto the nasal mucosa. Increased resistance on rhinomanometry after allergen application is an objective mean in proving allergy to airborne allergens when other allergy tests fail.

Shiva Swarodaya / Swara Yoga

Shiva Swarodaya is an ancient Sanskrit tantric text. A comment and translation termed as Swara yoga has been made by Satyananda Saraswati in 1983 It is also termed "Phonetical astrology": the "sound of one's own breath" and is written as a conversation between Shiva and Parvati.


The Tetrapodomorpha (also known as Choanata) are a clade of vertebrates consisting of tetrapods (four-limbed vertebrates) and their closest sarcopterygian relatives that are more closely related to living tetrapods than to living lungfish. Advanced forms transitional between fish and the early labyrinthodonts, such as Tiktaalik, have been referred to as "fishapods" by their discoverers, being half-fish, half-tetrapods, in appearance and limb morphology. The Tetrapodomorpha contains the crown group tetrapods (the last common ancestor of living tetrapods and all of its descendants) and several groups of early stem tetrapods, which includes several groups of related lobe-finned fishes, collectively known as the osteolepiforms. The Tetrapodamorpha minus the crown group Tetrapoda are the Stem Tetrapoda, a paraphyletic unit encompassing the fish to tetrapod transition.

Among the characters defining tetrapodomorphs are modifications to the fins, notably a humerus with convex head articulating with the glenoid fossa (the socket of the shoulder joint). Another key trait is the internal nostril or choana. Most fish have two pairs of nostrils, one on either side of the head for incoming water (incurrent nostrils) and another pair for outgoing water (excurrent nostrils). Early tetrapodomorphs such as Kenichthys had excurrent nostrils that had migrated to the edge of the mouth. In later tetrapodomorphs, including tetrapods, the excurrent nostril is positioned inside the mouth, where it is known as the choana.Tetrapodomorph fossils are known from the early Devonian onwards, and include Osteolepis, Panderichthys, Kenichthys and Tungsenia.

Tracking (film)

Tracking (1994) is a documentary about the band Phish and the recording of the album Hoist. It is directed by the band's bass player, Mike Gordon, who wrote, for the VHS packaging:

While in the studio recording the album 'Hoister' (sic) I sported a video camera. Sometimes I pushed the record button. Others, the stop. Alas, I edited. Using machines small yet sweet, I assembled Tracking. This isn't about railroad tracks or stuffing things up the tender nostril. It's about 48 tracks of sound, adjacent on strips of plastic. Like mixing lilac petals, coriander, chunks of butter, and fennel into a soup. Tracking is the recording of different sounds, adjacent on strips of plastic. . . .Many of the musicians on the album, Alison Krauss, Béla Fleck, and actor Jonathan Frakes, are shown recording tracks that eventually wound up on the album. The documentary is approximately 25 minutes long and was produced by Cactus Films.

External nose
Nasal cavity
Paranasal sinuses

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