Beschreibung: | VP 4777628, The vomeronasal organ. Representation of the main olfactory system and the vomeronasal organ in the rat, as well as their connections with the brain. The main olfactory system is constituted of olfactory epithelium (at the level of the nasal mucosa), that include chemoreceptors capturing the scented molecules. The informations are transmitted, via olfactory nerves (in green), to the brain, and more particularly to the main olfactory bulb (organ ovoïde pair). Mammals possess a second olfactory organ, of which the primary function is to detect pheromones. Those molecules are captured by chemoreceptors of the vomeronasal organ (also called Jacobson's organ), cylindric structure located at the level of the nasal septum (or the bony palate, depending on the species). Through the vomeronasal nerve (in yellow), the nerve impulse is propagated to the accessory olfactory bulb, pair organ located above the main olfactory bulb. The vomeronasal system would exist in the snakes and all mammals, but a state more or less developped. It plays a very important role among hoofed animals and felids, but is atrophied among men. The detection of pheromones is not a passive mecanism, but is activated among mammals by the Flehmen, a particular grimace : the animal lift the head, frown its nostrils and bunch up its lips uncovering its teeth. This operation facilitates the transfer of pheromones towards the vomeronasal organ. It is mainly used to detect individuals of the opposed sex in rut. [Urhebervermerk: JACOPIN/BSIP/vario images] [JEGLICHE VERWENDUNG nur gegen HONORAR und BELEG. URHEBER/AGENTURVERMERK wird gemaess Paragraph 13 UrhG und unserer AGB ausdruecklich verlangt. Es gelten ausschliesslich unsere AGB. Tel: +49-228-28616232, www.vario-images.com] |