Thermoregulation

• 37 degrees is the perfect temperature for our enzymes to function
• The hypothalamus controls thermoregulation
• We have receptors throughout our body, mostly in the skin and blood vessels which tell our brain if we are too hot or cold
• The brain will send signals to cool down or warm up
• If we are too cold we must conserve our heat and generate more. Vasoconstriction happens which directs blood to our central organs rather than our skin so less heat is lost. Erector muscles contract to raise the hairs on our skin which traps a layer of warm air. Also, we begin to shiver, this is the automatic contraction of muscles. However, shivering uses a lot of energy from respiration. This creates a waste of heat energy.
• When we are hot our blood vessels expand. This is vasodilation. More heat is lost to the surroundings this way. Our erector muscles relax and hairs lie flat so no insulating air is trapped. We also begin to sweat which when it evaporates we lose heat energy.