Exercise and Body Heat

Exercise and Body Temperature

• When exercising, the body produces a lot of heat due to muscle activity, which can lead to a problem maintaining the core body temperature of 98.6°F.
• One way the body gets rid of excess heat is through sweating, but another way involves the skin and blood vessels.

Skin and Blood Vessels

• The skin acts as insulation, keeping heat in when it's cold outside, but it also has blood vessels (capillary beds) that allow for heat exchange between the blood and tissue.
• These capillary beds are like "windows" that allow heat to escape past the skin's insulation.

Vasodilation and Heat Loss

• When the body is overheating, it opens up these "windows" (dilates the capillaries) through vasodilation, allowing more blood to pass through and increasing heat loss to the surroundings.
• Vasodilation increases blood flow to the skin's surface, resulting in more heat loss and helping the body maintain its core temperature.

Body Temperature Regulation

• The body maintains a core temperature of 98.6°F because it's the optimal temperature for the body's chemical reactions and machinery to function properly.
• The body regulates its temperature by controlling the size of its blood vessels, which affects how much heat is lost through the skin.

Constriction and Cold Weather

• When it's cold outside, the body closes these "windows" (constricts the capillaries) to reduce heat loss, making the skin's surface area colder.
• This is why hands feel extremely cold on a cold day, as the capillaries in the skin are constricted to minimize heat loss.

Regulation of Blood Vessels

• Blood vessels have smooth muscle cells that control their size, making them smaller when they contract and larger when they relax.
• The body regulates the contraction and relaxation of these smooth muscle cells through nerve impulses, controlling blood flow and heat loss.

Learn how exercise affects body temperature and why muscles release heat during physical activity. Discover the role of quadriceps and heart in heat production.