Nagavendra Sinopi
The hypothalamus is one of the brain's oldest and tiniest structures, accounting for only 4 gm of the 1400 gm of mature human brain weight. Despite this, the brain circuitry that controls basic life functions is remarkably conserved in this limited area. Some of the function that is carried by hypothalamus are fluid and electrolyte balance, from drinking to fluid absorption and excretion; metabolism, from eating to digestion, metabolic regulation, and energy expenditure, wake-sleep cycles and emergency reactions to environmental stressors; thermoregulation, from environment selection through heat production and conservation, and fever responses; wake-sleep cycles and emergency responses to environmental stressors and even the regulation of reproduction which includes controlling the reproductive hormone.