corpus mamillare, mamillary body, mammillary body - one of two small round structures on the undersurface of the brain that form the terminals of the anterior arches of the fornix

infundibulum - any of various funnel-shaped parts of the body (but especially the hypophyseal stalk)

pineal eye, third eye - a sensory structure capable of light reception located on the dorsal side of the diencephalon in various reptiles

neural structure - a structure that is part of the nervous system

nervus opticus, optic nerve, optic tract, second cranial nerve - the cranial nerve that serves the retina

hypophysis, pituitary, pituitary body, pituitary gland - the master gland of the endocrine system; located at the base of the brain

forebrain, prosencephalon - the anterior portion of the brain; the part of the brain that develops from the anterior part of the neural tube

basal ganglion - any of several masses of subcortical gray matter at the base of each cerebral hemisphere that seem to be involved in the regulation of voluntary movement

thalamus - large egg-shaped structures of gray matter that form the dorsal subdivision of the diencephalon

hypothalamus - a basal part of the diencephalon governing autonomic nervous system