Homeostasis: Body Temperature Animation Video
Transcript:
Homeostasis: Body Temperature
The systems of the body work together to maintain an internal state of physiological balance called homeostasis. The hypothalamus, a very small gland found in the brain, regulates body temperature to maintain the hypothalamic set point of ninety-eight point six degrees Fahrenheit.
When the body temperature falls below ninety-eight point six degrees, the hypothalamus responds by stimulating the sympathetic nervous system. The sympathetic nervous system causes the body to shiver and constricts blood vessels in the skin, which increases heat production in the body. The hypothalamus also signals the thyroid, an endocrine gland, to produce thyroxine, a hormone that increases metabolic rate and heat production. Together, these actions enable the body to conserve heat and body temperature begins to rise.
The hypothalamus also stimulates the sympathetic nervous system when the body temperature rises above ninety-eight point six degrees. In this case, the sympathetic nervous system stimulates sweat glands to increase sweat production. It also causes the blood vessels in the skin to widen and the thyroid gland to secrete less thyroxine. As the body loses heat, body temperature slowly drops and returns to the hypothalamic set point of ninety-eight point six degrees.