Module B1 - Homeostasis
Homeostasis is the body's way of keeping its internal environment stable. The internal environment is the conditions inside the body, such as water levels, blood glucose levels or body temperature. They must be kept stable so that the body functions properly and efficiently.
Osmoregulation is the control of water in the body. Water is lost from the body in different ways:
1. Sweat - it is produced in the sweat glands under the skin.
2. Breath - the air we breathe out contains levels of water vapour.
3. Urine - produced by the kidneys to remove waste products.
Thermoregulation is the process of keeping the internal body temperature constant.The normal human body temperature is 37°C. It must be kept this way as many chemical reactions and enzymes work best at this temperature. The hypothalamus is a part of the brain that controls the internal body temperature. It receives information from nerve endings in the dermis (the middle layer of the skin).
If the body temperature is below 37°C:
1. Erector muscles contract - cause body hair to stand upright. Although in humans this has little effect, in other mammals with thick fur, upright fur traps air and creates insulation.
2. Shivering - this is where muscles quickly contract. This releases heat and warms you up.
3. Vasoconstriction - blood flow to the skin is reduced and…