You can mark you interesting snippets of text that will be available through a unique link in your browser.


Jacobson's organ

Translation
Jacobson's organ
/jay"keuhb seuhnz/, Anat., Zool.
either of a pair of blind, tubular, olfactory sacs in the roof of the mouth, vestigial in humans but well-developed in many animals, esp. reptiles.
[1870-75; named after L. L. Jacobson (d. 1843), Danish anatomist]

* * *

also called  vomeronasal organ 

      an organ of chemoreception that is part of the olfactory system (smell) of amphibians (amphibian), reptiles (reptile), and mammals (mammal), although it does not occur in all tetrapod groups. It is a patch of sensory cells within the main nasal chamber that detects heavy moistureborne odour particles. Airborne odours, in contrast, are detected by the olfactory sensory cells located in the main nasal chambers. Some groups of mammals also initiate a behaviour known as the flehmen response, in which the animal facilitates the exposure of the vomeronasal organ to a scent or pheromone by opening the mouth and curling the upper lip during inhalation.

      This organ was named for its discoverer, Danish anatomist Ludvig Levin Jacobson, in 1811. It is a paired structure; in the embryo stages of all tetrapods, each half arises as an evagination of the floor of a nasal sac. In fully developed crocodilians (crocodile), turtles (turtle), birds (bird), cetaceans (cetacean), and many advanced primates (primate), this structure is absent or substantially underdeveloped. For most tetrapods that possess a Jacobson's organ, ducts connect the organ directly to the nasal cavity; however, in squamates (lizards (lizard) and snakes (snake)) each organ opens on the roof of the buccal cavity (mouth). The tongue carries odour particles from the outside to the vomeronasal openings on the roof of the mouth, and the particles then move into the vomeronasal organ. After these particles reach the organ, some of the chemical compounds they contain bind to receptor molecules, and sensory messages are sent to the brain.

      The Jacobson's organ is useful in the process of communicating chemical messages, such as readiness for sexual activity (sex), between members of the same species. The organ also helps snakes hunt and track their prey. Much evidence suggests that this organ may also be involved in the detection of chemical signals related to aggression and territoriality. See also chemoreception.

George R. Zug
 

* * *


Universalium. 2010.

  
Share  

Look at other dictionaries:

  • Jacobson's organ — noun Etymology: Ludvig L. Jacobson died 1843 Danish anatomist Date: 1885 vomeronasal organ …   New Collegiate Dictionary

  • Jacobson — (patronymisch gebildeter Familienname, „Sohn des Jacob“) ist der Name folgender Personen: Anders Jacobson (* 1984), schwedischer Handballspieler Arthur Jacobson (1901–1993), US amerikanischer Regieassistent Ben Jacobson (* 1983), US… …   Deutsch Wikipedia

  • Jacobson-Organ — Das Jacobson Organ (auch Jacobsonsches Organ oder Vomeronasales Organ, lat. Organon vomeronasale) ist ein Geruchsorgan vieler Wirbeltiere. Es besteht aus winzigen Einbuchtungen (Durchmesser zwischen 0,2 und 2 Millimeter) auf beiden Seiten der… …   Deutsch Wikipedia

  • Jacobson — is a surname, and may also refer to:* Jacobson, Minnesota, USA * Jacobson v. United States , American legal case * Jacobson stores, American franchise * Vomeronasal organ, an auxiliary olfactory sense organ also called Jacobson s organ See also * …   Wikipedia

  • vomeronasal organ — noun Date: circa 1926 either of a pair of small blind pouches or tubes in many vertebrates that are situated one on either side of the nasal septum or in the buccal cavity and that are reduced to rudimentary pits in adult humans but are developed …   New Collegiate Dictionary

  • Vomeronasal organ — Infobox Anatomy Name = Vomeronasal organ Latin = organum vomeronasale GraySubject = 223 GrayPage = 996 Caption = Frontal section of nasal cavities of a human embryo 28 mm. long (Vomeronasal organ of Jacobson labeled at right) Caption2 = Precursor …   Wikipedia

  • Jacobsonsches Organ — Das Jacobson Organ (auch Jacobsonsches Organ oder Vomeronasales Organ, lat. Organon vomeronasale) ist ein Organ vieler Wirbeltiere. Es besteht aus winzigen Einbuchtungen (Durchmesser zwischen 0,2 und 2 Millimeter) auf beiden Seiten der… …   Deutsch Wikipedia

  • Vomeronasales Organ — Das Jacobson Organ (auch Jacobsonsches Organ oder Vomeronasales Organ, lat. Organon vomeronasale) ist ein Organ vieler Wirbeltiere. Es besteht aus winzigen Einbuchtungen (Durchmesser zwischen 0,2 und 2 Millimeter) auf beiden Seiten der… …   Deutsch Wikipedia

  • Israel Jacobson — (October 17, 1768, Halberstadt ndash; September 14, 1828, Berlin) was a German philanthropist and, according to Borowitz and Patz in Explaining Reform Judaism (1985), is considered the father of the Reform movement in Judaism.OriginsThe only son… …   Wikipedia

  • Ludwig Levin Jacobson — (* 10. Januar 1783 in Kopenhagen; † 29. August 1843 ebenda) war ein dänischer Mediziner. Ludwig Levin Jacobson Inhaltsverzeichnis …   Deutsch Wikipedia

  • Harry S. Truman — This article is about the United States president. For other uses of the name, see Harry Truman (disambiguation). Harry Truman 33rd President of the United States …   Wikipedia