What Is the Purpose of the Jacobson's Organ?

In dogs, the Jacobson's organ allows the detection of pheromones from other canines.

The Jacobson's organ is an olfactory sense organ in many species of animals. It allows them to perceive pheromones, or chemical messages, from other animals of the same species.

Significance

Sensing pheromones with the Jacobson's organ is important for animals because these chemical stimuli help determine reproductive and other social behaviors. Pheromones are found in animals' scent glands, saliva, feces and urine.

Location

In mammals and reptiles, the Jacobson's organ is located in the roof of the mouth and consists of two fluid-filled sacs that are attached to the nasal cavity.

Use

Many species, including cats and dogs, use what is called the Flehmen reaction to increase their perception of pheromones with the Jacobson's organ. This process involves lifting their upper lips and opening their mouths to enhance the opening of the ducts connected to the organ.

Reptiles

When a snake or lizard flicks out its tongue, it is actually picking up scent particles, according to Worldbook.com. When it pulls in its tongue again, it transfers the scent to the Jacobson's organ, allowing it to detect odors.

Humans

Peter Burnham, of the department of Physiology and Pharmacology at the University of Bristol, England, says that as humans evolved, the genes necessary for the Jacobson's organ's function became redundant. Therefore, it is highly unlikely that the organ plays a role in human behavior, he says.

References

• Peteducation.com: Pheromones: How the Sense of Smell Influences Dog Behavior
• Worldbook.com: Sense Organs
• Thenakedscientists.com: Science Questions