Definition of Goose Bumps
A bumpy texture to the skin, also called gooseflesh, that results when the erector muscles in the hair follicles contract, causing the hair to “stand up.” Goose bumps occur when a person becomes chilled or fearful, a vestigial response no longer physiologically useful in humans.
The physiologic mechanism that causes goose bumps, called the pilomotor reflex or piloerection, is involuntary.
Researchers believe it is in part the consequence of the release of stress hormones, primarily epinephrine (also called adrenaline), which stimulates the hypothalamus.
In other mammals the pilomotor reflex raises the hair or fur for warmth by trapping air near the skin’s surface or to present an intimidating appearance by making the animal appear larger than it is. Goose bumps often accompany shivering, rapid and involuntary muscle contraction to generate heat.
See also HORMONE; METABOLISM; MUSCLE; THYROID GLAND.
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