Describe the process by which the skin cools the body when warm and warms the body when cold?

Answer 1

Humans are exposed to a lot of environmental temperature changes but the system we are equipped with to deal with this has limits. "Our bodies have anatomical and physiological mechanisms that keep body temperatures within acceptable limits, regardless of environmental conditions." (Martini, Nath. 2009) Thermoregulation is the process where our bodies maintain acceptable temperatures. If our bodies are not maintained at acceptable temperatures it can cause serious problems such as convulsions, disorientation and permanent cell damage. Water is a good heat conductor and nearly 2/3 of our body weight is water. The bloodstream and diffusion distribute the heat that regions of the body produce. In order for the body temperature to remain at one level the heat must go out of the body at the same rate that it made.

The four basic processes involved in heat exchange with the environment are radiation, conduction, convection and evaporation. The heat loss and heat gain center coordinate the systems to control the body's temperature by changing the rate heat is made and lost.

To cool the body three things occur;

• 1. "Inhibition of the vasomotor center causes peripheral vasodilation and warm blood flows to the surface of the body." (Martini, Nath. 2009)
• 2. "As blood flow to skin increases, sweat glands are stimulated to increase their secretory output." (Martini, Nath. 2009)
• 3. "The respiratory centers are stimulated and the depth of respiration increases." (Martini, Nath. 2009)

To warm the body the heat gain center starts to work and either shivering thermogenesis or non-shivering thermogenesis takes place. "In shivering thermogenesis a gradual increase in muscle tone increases the energy consumption of skeletal muscle tissue throughout your body and the more energy consumed, the more heat is produced. Non shivering thermogenesis involves the release of hormones that increases metabolic activity of all the tissues." (Martini, Nath. 2009)

Reference

Martini, F.H, Nath, J.L. (2009) Fundamentals of Anatomy and Physiology (8th Edition) Pearson Education