Functions of the skin
There are six functions of the skin, which are:
- Sensation – the skin contains sensory nerve endings that send messages to the brain. These nerves respond to touch, pressure, pain, cold and heat and allow us to recognise objects from their feel and shape
- Excretion – waste products and toxins are eliminated from the skin through the sweat glands.
- Absorption – the hair follicles, the sebaceous gland opening, and the skin are able to absorb, penetration can be affected by the health and condition of the skin.
- Protection – the stratum corneum protects the body against its environment. The structure, rate of replacement and physical repair properties of the outer layer protect against bacterial invasion and minor injury. The skin is waterproof and contains body fluid whilst preventing entry of large quantities of fluid through the epidermis.
- Elimination – sweat is eliminated from the skin to aid heat regulation.
- Heat regulation – it is important for the body to have a constant internal temperature of 36.8 degress Celsius (○C) for our bodies to The skin helps to maintain this temperature by:
- Vasoconstriction – this occurs when the body becomes cold. The blood vessels constrict reducing the flow of blood through the capillaries. Heat lost from the surface of the skin is therefore reduced.
- Vasodilation – this occurs when the body becomes too hot. The capillaries expand and the blood flow increases, this allows heat to be lost from the body by radiation.
- Goose bumps – contraction of the arrector pili muscle when we are cold causes the hairs to stand on end, keeping a layer of warm air close to the body. This was probably of more use to our ancestors, who were generally hairier.
- Shivering – when we are cold this helps to warm the body, as the contraction of the muscles produces heat within the body.
- Sweating – in hot conditions the rate of sweat production increases. The eccrine glands excrete sweat onto the skin surface and heat is lost as the water evaporates from the skin.