Part 1: Image-Mapped Tutorial
Part 2: Matching Self-Test
Part 3: Multiple-Choice Self-Test
9. The Sympathetic Division of the ANS when activated will cause the contraction of muscles attached to hair follicles. When these muscles contract, the hair becomes erect and goose bumps result.
| Advanced |
This physiological response is unimportant in humans, but appears to be a relic from hairier ancestors. When the blood supply is increased to the limbs during sympathetic activation, much heat can be lost via the blood circulating close to the skin. Erection of body hair helps nonhuman mammals to conserve warmth during these times.