The Human Brain : From Neurone to Nervous System


  1. The hypothalamus weighs only 4 grams, but regulates energy, fluid and electrolyte metabolism, body temperature, autonomic and endocrine functions in the body, and has strong associations with the limbic system, stress, and emotional life.

  2. The hypothalamus, as its name suggests, lies below the thalamus, and has a close relationship with the pituitary gland. The two sides of the hypothalamus are separated by the third ventricle, and the blood brain barrier is deficient in this region

  3. There are unique vascular connections with the anterior portion of the pituitary (which has its embryological origin in the roof of the mouth). In addition there are important neural connections with the posterior pituitary, which is derived embryologically from the developing brain.

  4. The hypothalamus has important links with the Limbic System through the Fornix and the Striae Terminalis, which are relevant to stress and anxiety. Another important input is the visual pathway, important for the suprchiasmatic nucleus in determining sleep-waking and other diurnal cycles.

  5. Output pathways of the hypothalamus include the endocrine system, mediated by neurosecretory neurones in various hypothalamic nuclei; and the autonomic nervous system.

  6. Key Words: Rathke's Pouch, Pituitary-Portal System, Endocrine Control, Autonomic Nervous System.