Reptiles vomeronasal organ

Rehorek S.J., Firth B.T. and Hutchinson M.N. (2000). The structure of the nasal chemosensory system in squamate reptiles, 2 Lubricatory capacity of the vomeronasal organ. J Biosci 25, 181-190. 

FIGURE 5.8 Location of the vomeronasal organ (VNO, cross-hatched) in amphibians and reptiles. Arrows show air entering through the external nares at top and exiting through the choanae at bottom. From there, VNO receives air with odors. N nasal cavity. In lizard, VNO receives stimuli from mouth cavity below, with help from tongue. (Redrawn after Romer, 1959.)... 

Table 5.1 Role of vomeronasal organ in behavior of amphibians and reptiles...

The two components of the VN system examined in the present study are the vomeronasal organ and the accessory olfactory bulb. The VNO is a paired, chemoreceptive structure present at the base of the nasal septum in most terrestrial mammals, amphibians and reptiles. The VNO s bipolar receptor neurons detect pheromonal signals (Halpem, 1987 Farbman, 1992). 

Kolnberger I. (1971). Comparative studies of the olfactory epithelium especially the Vomeronasal (Jacobson s) Organ in Amphibia, Reptiles and Mammals. Z Zellf Mikrosk Anat 122, 53-67. 

The vomeronasal system, also known as the accessory olfactory system, consists of chemoreceptors, organized into the VNO, the vomeronasal nerve, its terminal, the accessory olfactory bulb, and more central pathways. First described by Jacobson in 1811, the VNO has been studied intensely. We now know how stimuli reach it and what behaviors it mediates. The VNO occurs in amphibians, reptiles, and mammals. Among mammals, it is best developed in marsupials and monotremes. In birds it only appears during embryogenesis. The VNO and its function are best known for squamate reptiles, particularly snakes, and rodents and ungulates among the mammals. 

Halpem, M., 1987, The organization and function of the vomeronasal system, Ann. Rev. Neurosci. 10 325-362. Halpem, M., 1992, Nasal chemical senses in reptiles structure and function, in Biology of the Reptilia, Vol. 18, C. Gans and D. Crew, eds., Univ. Chicago Press, Chicago, pp. 424-532. 

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