Hypothalamus: small part of diencephalon below the thalamus, forming the floor and lower part of the lateral walls of the third ventricle.
Weightabout 4 g (0.3% of brain mass)
Controls the autonomic nervous system, endocrine system and limbic system; called the "head ganglion of the autonomic nervous system" (Sherrington).
Subdivisions and Boundaries
Anteroposteriorly divided into four regions, each containing its own nuclei: preoptic, supraoptic, tuberal and mammillary.
Mediolaterally divided, using the anterior column of fornix as landmark, into a medial zone (periventricular and intermediate sub-zones) and a lateral zone.