Thermoregulation (physiology) Flashcards
Which mechanism is responsible for thermoregulation?
Homeostasis
How is heat lost? (4)
-radiation
-conduction
-vaporization of water in respiratory passages and on the skin.
-some is lost in urine and faeces.
Normal body temperature in humans?
37 degrees celsius
What are the factors that influence body temperature? (8)
Age, sex, diurnal variation, meals, exercise, sleep, menstrual cycle, and emotions.
Which organ is responsible for thermoregulation?
The hypothalamus
What do we call the receptors that detect changes in blood temperature, and where are they found?
Central thermoreceptors, found in hypothalamus.
Where in the hypothalamus is heat gain or loss regulated?
Pre-optic area of the anterior hypothalamus.
Four processes that are resp for heat exchange with environment.
Radiation, evaporation, convection and conduction.
Explain the radiation process in thermoregulation.
When warmer objects lose heat in a colder environment.
Explain the convection process of thermoregulation.
Losing heat to air that moves across the body surface.
Explain the conduction process of thermoregulation.
Direct transfer of energy through touch/physical contact.
What are the heat gain mechanisms? (5)
-Biochemical reactions
-Ingestion of food
-Hormones(NA, A and thyroid hormones)
-Constriction of skeletal muscles (eg during exercise)
-brown fats in infants.
Effects of high body temp (3)
-Vasodilation causing blood flow to skin to increase.
-Respiratory centers are stimulated causing the depth of respiration increases.
-Sweat glands are stimulated to increase secretory input.
Effects of low body temp (5)
-Sympathetic vasomotor center decreases blood flow to the skin by causing vasoconstriction.
-Blood returning from limbs is shunted into insulated, deep veins.
-Shivering, hunger, curling up, increased secretion of A and NA.
How does shivering produce heat?
It increases muscle tone which ultimately increases energy consumption in skeletal muscles, producing heat.
