Answer to Question #126654 in Human Anatomy and Physiology for Ramseyer Brace

Question

It is a warm day and you feel a little chilly. On checking your temperature, you find that your body temperature is 1.5 degrees below normal. Suggest 3 possible reasons for this situation. Describe briefly how your body will react to this dip in temperature.

Answer 1

When we go out on a hot summer day and our body temperature rises, the hypothalamus of the brain detects this change and send signals to various organs so that we sweat. As water is excreted by the sweat glands onto the skin, it evaporates in the air. Because it takes a great deal of energy for a water molecule to change from a liquid to a gas, evaporating water (in the form of sweat) takes with it a great deal of energy from the skin. Water evaporating from the skin cools the body.

In addition, our blood vessels dilate to bring the blood near the skin’s surface to dissipate heat away from warm inner body. This lets your body release heat through heat radiation.

Convection is the transfer of heat to the air surrounding the skin. The warmed air rises away from the body and is replaced by cooler air that is subsequently heated. The convection currents created by the temperature changes continue to draw heat away from the body more quickly than the body can replace it. Wind makes us feel cooler on hot days.

If our body temperature is falling, the hypothalamus stimulates processes that conserve or generate heat, such as decreasing breathing rate and decreasing heat rate.