5.2.3 Thermoregulation

Question 1

What is blood temperature monitored by?

Answer 1

• Hypothalamus.

Question 2

Describe vasodilation.

Answer 2

• Sweat glands in the skin release more sweat. The sweat evaporates, transferring heat energy from the skin to the environment.
• Blood vessels leading to the skin capillaries become wider - they dilate - allowing more blood to flow through the skin, and more heat to be lost to the environment.

Question 3

Describe vasoconstriction.

Answer 3

• Skeletal muscles contract rapidly and we shiver. These contractions need energy from respiration, and some of this is released as heat.
• Blood vessels become narrower - they contract - which allows less blood to flow through the skin and conserve the core body temperature.