What is Jacobson's organ and where can it be seen in the human embryo?

Jacobson's organ, also known as the vomeronasal organ, is a specialized structure of the olfactory system that functions in chemoreception. It is a paired structure that detects chemical signals, such as pheromones, which are often involved in innate behavioral and physiological responses.12

In the embryo stages of all tetrapods, including humans, each half of the organ arises as an evagination of the floor of a nasal sac. While the organ is well-developed in many amphibians, reptiles, and mammals, it is reduced to rudimentary pits in adult humans.123