Vomeronasal organ

The vomeronasal organ, also known as Jacobson’s organ, is a paired chemoreceptive structure located at the base of the nasal septum in many mammals. It is part of the accessory olfactory system, involved in detecting pheromones and mediating reproductive and social behaviors.

Situated in a bony canal formed by the vomer and palatine bone, bilaterally on either side of the nasal septum. It opens into the incisive duct in many species (e.g., horses, cats, dogs).

The vomeronasal organ is composed by :

• the sensory epithelium, that contains bipolar neurons that detect pheromonal stimuli;

• the vomeronasal cartilage;

• the incisive duct, witch communicates with the oral or nasal cavity, depending on the species.

Its Innervated primarily via the vomeronasal nerve, a branch of the olfactory nerves and possibly the trigeminal nerve. It is involved in pheromone detection, it plays a key role in behaviors such as mating, territorial marking, and maternal bonding. In species like cats and horses, it is activated during the Flehmen response (a behavioral reaction that facilitates pheromone transfer to the organ).