The hypothalamus is a small area at the base of the brain, weighing about 4 gm out of the 1400 gm brain weight of an adult human, yet it performs a wide range of functions that are vital for the survival of the individual. In general, the hypothalamus acts as a integrator to regulate and coordinate basic functions necessary for life, such as fluid and electrolyte balance; feeding and energy metabolism; wake-sleep cycles; thermoregulation; stress responses; and sexual behavior and reproduction.The hypothalamus (pronounced: hi-po-THA-luh-mus), a collection of specialized cells that is located in the lower central part of the brain, is the main link between the endocrine and nervous systems. Nerve cells in the hypothalamus control the pituitary gland by producing chemicals that either stimulate or suppress hormone secretions from the pituitary.