regulating body temperature

• Cold climate

  1. Blood and skin temp decrease below normal
  2. temp receptors detect change in skin temp and produce nerve impulses sent to hypothalamus (decrease in blood temp detected by hypothalamus)
  3. corrective mechanisms:
  4. vasoconstriction: less blood flows to capillaries, so not enough blood(less oxygen and glucose in cells), less heat is lost through c.c.r
  5. shivering: contraction of skeletal muscles, increase rate of respiration and heat released for internal body
  6. contraction of hair erector muscle: trap layer of air on the skin, reduces heat loss
  7. blood temp increase back to normal
• Hot climate

  1. Skin and blood temp increase above normal
  2. Thermoreceptors in skin detect change in temp and produce nerve impulses, sent to hypothalamus
  3. corrective mechanisms:
  4. vasodilation: more blood flows to capillaries, more heat is lost through skin by conduction, convection and radiation
  5. sweating: more water evaporate which remove latent heat
  6. decrease rate of metabolism: releases less heat internally from respiration
  7. blood temp decrease back to normal
• Exercise

  1. increased muscular contractions
  2. increase blood temp are detected by thermoreceptors in hypothalamus and produce nerve impulses sent to hypothalamus
  3. corrective mechanisms:
  4. vasodilation: more blood flows to capillaries, more heat is lost through skin by conduction, convection and radiation
  5. sweating: more water evaporate which remove latent heat
  6. decrease rate of metabolism: releases less heat internally from respiration
  7. blood temp decrease back to normal