Body Temperature Flashcards
homeothermic
maintaining a relatively constant body temperature, independent of the temperature of the surrounding environment
metabolism
makes use of mitochondria to produce energy
core temperature
warm, internal
shell temperature
cool, external
thermoregulation
ability to maintain a constant body temperature despite external temperature changes
temperature regulating centers located in the hypothalamus
mechanisms of heat exchange
used to maintain homeostasis when the body isn’t thermoneutral
radiation
transfer of heat without contact, from an object to its environment and visa versa via infrared rays
evaporation
transfer of heat due to evaporation of water
only way to regulate body temperature when external environment is >37*C
major heat loss mechanism
conduction
exchange of heat between objects of different temperatures that are in direct contact
convection
transfer of heat through circulation of air currents or liquid along the skin surface
heat loss
depends on the blood flow through the skin capillaries
promoted by vasodilation
metabolism
major source of internal heat generation
non-hypothalamic
shivering thermogenesis
skeletal muscle metabolism
somatic neurons activated
non-shivering thermogenesis
brown fat metabolism
SNS activated to release norepinephrine which activates the uncoupling protein for the mitochondrial and oxidative phosphorylation uncoupling
brown fat
used in response to cold as it has many mitochondria that can be used for energy (heat) production
heat conservation
vasoconstriction
piloerection
behavioral changes
anterior hypothalamus
heat loss center
warm-sensing neurons
excited by increase in temperature
stimulates sweating and vasodilation
posterior hypothalamus
heat gain center
cold-sensing neurons
excited by decrease in temperature
stimulates conservation, and shivering and non-shivering thermogenesis
thermoreceptors
sensory neurons monitor skin and core temperature then send information to the hypothalamus