Hypothalamus: Anatomy
The hypothalamus is an almond-sized structure located at the base of the brain, positioned below the thalamus and directly above the pituitary gland (hypophysis). Despite accounting for less than 1% of the brain’s total volume, it serves as the master control center for homeostasis, bridging the central nervous system and the endocrine system.
| Region | Major Nuclei / Areas | Primary Functions |
|---|---|---|
| Preoptic | Preoptic area; Medial preoptic nucleus; Lateral preoptic area | Heat dissipation; reproductive behaviors; sleep initiation |
| Supraoptic (Anterior) | Paraventricular nucleus (PVN); Supraoptic nucleus (SON); Anterior nucleus; Suprachiasmatic nucleus (SCN) | Oxytocin & vasopressin production; circadian rhythm control; parasympathetic activation; heat loss |
| Tuberal (Middle) | Dorsomedial nucleus (DMH); Ventromedial nucleus (VMH); Arcuate nucleus | Feeding patterns; satiety; aggression modulation; pituitary regulation; appetite control |
| Mammillary (Posterior) | Mammillary bodies; Posterior nucleus | Memory circuitry; heat conservation; sympathetic activation |
| Medial Zone | PVN; VMH; DMH; Arcuate | Core endocrine & autonomic integration |
| Lateral Zone | Lateral hypothalamic area; Medial forebrain bundle | Arousal; feeding drive; reward-related behaviors |
| Periventricular Zone | Thin periventricular layer | Neuroendocrine control of anterior pituitary |