Exercise 27: Body Temperature Regulation

homeotherms

humans maintain constant internal temperature, regardless of the environmental temperature

endotherms

humans internally generate the majority of our heat. this heat is generated by metabolic reactions. (ex: we generate heat by shivering thermogenesis)

what is body temperature regulated by?

hypothalamus

• responds to the sensory information from the thermoreceptors by adjusting metabolic rate via hormones, vasodilation or vasoconstriction and sweating

what do peripheral thermoreceptors detect ?

temperature in the extremities

what do central thermoreceptors detect ?

temperature in the body core

hypothermia

body temperature below the normal rate

• decreases metabolism results in decreased ability to think rationally and decreased ability to move skeletal muscle, thus decreasing the ability to generate more heat

radiation

the radient gain or loss of heat following a thermal gradient

• if outside is cooler than the body temp, the thermal gradient will lead to heat loss from the body

• if outside is warmer than the bod temp, the thermal gradient will lead to heat gain by te body

conduction

the gain or loss of heat following a thermal gradient due to physical contact. radiation transfers heat through air, conduction transfers heat via direct contact. (ex: warming hands by holding a hot cup of coffee)

evaporation

the loss of heat as water is converted from a liquid to a vapor

active water loss

occurs with sweating

passive water loss

occurs with respiration and through our water-permeable skin

relative humidity

how much water vapor in the air compared to how much the air could hold at that temperature

convection

the heat loss or gain as a result of moving air or water