The hypothalamus is a bipartate structure, with two equal halves on both hemispheres of the brain. It is medially transversed by the 3rd ventricle, forming a physical barrier between certain aspects of both halves of the hypothalamus.
The hypothalamus has three main regions: lateral, medial and periventricular, which serve a diverse number of functions.
The hypothalamus is an aggregate of specific and unique nuclei, but most of which are interconnected.
The hypothalamus is connected to the pituitary glands by a fleshy stalk called the hypothesis. The pituitary gland has two lobes: posterior and anterior. The hypothalamus's periventricular region maintains axonal connections to the posterior pituitary lobe. The hormones secreted by the posterior pituitary are manufactured in the hypothalamus and sent through the hypothesis to the posterior pituitary, where they are uptaken by the vascular system. Other neuronal populations in the hypothalamus secrete secretory products that regulate the release of endocrines from the anterior pituitary gland.
The hypothalamus is a coordinating center for the autonomic and somatic expression of emotion.
The posterior lobe of the hypothalamus is controlled by the cortical areas of the brain.
The lateral areas of the hypothalamus are responsible for taste perception, and prompt secretion of insulin and digestive enzymes. They are also associated with learning and reinforcement by modulating dopamine neurotransmission, and may therefore be responsible in part for the Garcia Effect.
The medial areas of the hypothalamus is responsible for depressing hunger by influencing stomach motility and inhibiting fat production.
The paraventricular areas of the hypothalamus are responsible for satiety.