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Encyclopedia > Vomeronasal organ
Vomeronasal organ
Frontal section of nasal cavities of a human embryo 28 mm. long. (Vomeronasal organ of Jacobson labeled at right.)
Latin organum vomeronasale
Gray's subject #223 996
Precursor olfactory placode
Dorlands/Elsevier o_06/12596317

The vomeronasal organ (VNO) or Jacobson's organ is an auxiliary olfactory sense organ in some tetrapods. In adults, it is located in the vomer bone, between the nose and the mouth. It develops from the nasal (olfactory) placode, at the anterior edge of the neural plate. (cranial nerve zero) Image File history File links Gray51. ... Latin is an ancient Indo-European language originally spoken in Latium, the region immediately surrounding Rome. ... This article or section is in need of attention from an expert on the subject. ... A placode is an area of thickening in the embryonic epithelial layer where some organ or structure later develops. ... Elseviers logo. ... Olfaction (the sense of smell) is the detection of chemicals dissolved in air. ... Classes Synapsida Sauropsida Amphibia A tetrapod (Greek tetrapoda, four-legged) is a vertebrate animal having four feet, legs or leglike appendages. ... The vomer bone is one of the unpaired facial bones of the skull. ... A placode is an area of thickening in the embryonic epithelial layer where some organ or structure later develops. ... The neural plate is thick and flat bundle of ectoderm which develops in the embryo into the nervous system. ...

Contents

Function

Its function is somewhat mysterious. The sensory neurons within the vomeronasal organ detect distinct chemical compounds, often but not always large non-volatile molecules. Drawing by Santiago Ramón y Cajal of neurons in the pigeon cerebellum. ... A chemical compound is a chemical substance consisting of two or more different chemically bonded chemical elements, with a fixed ratio determining the composition. ...


In animals (other than humans)

The vomeronasal organ is used in the detection of pheromones in some animals such as mice, although some pheromones are detected by the main olfactory epithelium, and the vomeronasal organ detects other compounds in addition to pheromones. Cats sense nepetalactone from catnip using the vomeronasal organ. Fanning honeybee exposes Nasonov gland (white-at tip of abdomen) releasing pheromone to entice swarm into an empty hive A pheromone is any chemical or set of chemicals produced by a living organism that transmits a message to other members of the same species. ... It has been suggested that C57BL-6 be merged into this article or section. ... The olfactory epithelium is a specialized epithelial tissue inside the nasal cavity that is involved in smell. ... Trinomial name Felis silvestris catus (Linnaeus, 1758) The cat (or domestic cat, house cat) is a small carnivorous mammal. ... Structural formula of nepetalactone Nepetalactone is a lactone chemical compound first isolated in the plant catnip, Nepeta cataria (apparently named after the Italian town of Nepete). ... It has been suggested that this article or section be merged with Nepeta. ...


Snakes use it to sense smell prey, sticking their tongue out and touching it to the opening of the organ. Elephants transfer chemosensory stimuli to the vomeronasal opening in the roof of their mouths using the "finger" at the tips of their trunks. Some mammals use a distinctive facial movement called flehmen to direct compounds to this organ, while in some other mammals the entire organ contracts or pumps to draw in compounds. For other uses, see Snake (disambiguation). ... For other uses, see Tongue (disambiguation). ... Genera and Species Loxodonta Loxodonta cyclotis Loxodonta africana Elephas Elephas maximus Elephas antiquus † Elephas beyeri † Elephas celebensis † Elephas cypriotes † Elephas ekorensis † Elephas falconeri † Elephas iolensis † Elephas planifrons † Elephas platycephalus † Elephas recki † Stegodon † Mammuthus † Elephantidae (the elephants) is a family of pachyderm, and the only remaining family in the order Proboscidea... The Flehmen response is a particular type of curling of the lips in ungulates, felids, and many other mammals, which facilitates the transfer of chemicals into the vomeronasal organ. ...


In humans

Anatomical studies demonstrate that in humans the vomeronasal organ regresses during fetal development, as is the case with some other mammals, including other apes, cetaceans, and some bats. There is no evidence of a neural connection between the organ and the brain in adult humans. Nevertheless, a small pit can be found in the nasal septum of some people, and some researchers have argued that this pit represents a functional vomeronasal organ. Thus, its possible presence in humans remains controversial. Trinomial name Homo sapiens sapiens Linnaeus, 1758 Humans, or human beings, are bipedal primates belonging to the mammalian species Homo sapiens (Latin: wise man or knowing man) under the family Hominidae (the great apes). ... Families Hylobatidae Hominidae Apes are the members of the Hominoidea superfamily of primates, which includes humans. ... Suborders Mysticeti Odontoceti Archaeoceti (extinct) (see text for families) The order Cetacea includes whales, dolphins and porpoises. ... Suborders Megachiroptera Microchiroptera See text for families. ... The nasal septum separates the left and right airways in the nose, dividing the two nostrils. ...


See also

Olfaction (the sense of smell) is the detection of chemicals dissolved in air. ... The olfactory system is the sensory system used for olfaction. ... A stallion exhibits the flehmen response by curling back his lips. ... Fanning honeybee exposes Nasonov gland (white-at tip of abdomen) releasing pheromone to entice swarm into an empty hive A pheromone is any chemical or set of chemicals produced by a living organism that transmits a message to other members of the same species. ... Odor receptors on the antennae of a Luna moth An odor or odour (see spelling differences) is a chemical dissolved in air, generally at a very low concentration, which we perceive by the sense of olfaction. ... In the septum close to the nasopalatine recess a minute orifice may be discerned; it leads backward into a blind pouch, the rudimentary vomeronasal organ of Jacobson, which is supported by a strip of cartilage, the vomeronasal cartilage (or Jacobsons cartilage). ...

External links

  • Neuroscience Program FSU
  • "Jacobson's Organ and the Remarkable Nature of Smell" by Lyall Watson
  • Annals of New York Academy of Science, 1998 (peer-reviewed link regarding verified presence of functional vomeronasal organ in humans.) [1]

  Results from FactBites:
 
Vomeronasal organ - Wikipedia, the free encyclopedia (266 words)
The vomeronasal organ (VNO) or Jacobson's organ (sometimes misspelled "Jacobsen's") is an auxiliary olfactory sense organ in some tetrapods.
The vomeronasal organ is used in the detection of pheromones in some animals such as mice, although some pheromones are detected by the regular olfactory organ, and the vomeronasal organ detects other compounds in addition to pheromones.
Anatomical studies demonstrate that in humans the vomeronasal organ regresses during fetal development, as is the case with some other mammals, including cetaceans, some bats, and apes.
  More results at FactBites »


 

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