Mammillary Bodies

The mammillary bodies are a pair of spherical masses of gray matter at the base of the brain, located between the hypophysis and oculomotor nerve that receives and relays olfactory impulses. Being part of the limbic system, the mammillary bodies are situated at the ends of the anterior arches of the fornix, and are composed of two groups of nuclei, the medial mammillary nuclei and the lateral mammillary nuclei. The mammillary bodies function as a relay for impulses coming from the amygdalae and hippocampi, via the mamillo-thalamic tract to the thalamus. This circuit, from amygdalae to mamillary bodies, and then on to the thalamus, is part of the larger Papez circuit.