Hypothalamus
NervousOrgansHead
- What it is
- The floor and lower walls of the third ventricle, below the thalamus and above the optic chiasm; the paired mammillary bodies bulge from its back and the funnel-shaped infundibulum carries the pituitary stalk down to the pituitary gland (built with the glands).
- Function
- Keeps the internal environment constant: body temperature, hunger, thirst and water balance, sleep-wake rhythm, sexual behaviour and the stress response, largely by controlling the pituitary.
- Size
- About 4 g - under 1% of the brain; roughly the size of an almond
- Clinical note
- It makes antidiuretic hormone and oxytocin, which travel down axons to the posterior pituitary; damage causes diabetes insipidus (large volumes of dilute urine).