You have probably experienced goosebumps at many times in your life. Goosebumps are little bumps that rapidly appear on your skin under certain conditions such as when experiencing cold, fear or emotion.
Etymology of Goose Bumps
The term "goose bumps" was introduced in 1933 into the Merriam-Webster Collegiate Dictionary to refer to "a roughness of the skin produced by erection of its papillae especially from cold, fear or a sudden feeling of excitement." They are also known as "Goose Flesh" or "cutis anserina" (literally meaning "Goose Skin"). The reason this condition is intrinsically linked with a goose is that when we experience goosebumps, our bumpy skin resembles that of a goose that has recently had its feathers plucked, pulling up bumps where the feather was.
Why They Happen
Goose Bumps start from a stimulus that causes an involuntary nervous discharge from the sympathetic nervous system. This discharge then contracts the arrectores pilorum (hair erector muscles), which then raise the hair follicles above the skin.
Medical science has never found a concrete reason for why goosebumps actually appear, but a few predominant theories abound. One is that we do it for the same reason animals do -- to make themselves look bigger to prey. This also keeps the animal warmer by increasing the amount of air between the hairs to trap body heat. Another idea is that our fight-or-flight reaction coupled with an increased heart rate would mean that a greater blood flow would reach the muscles, thus providing them with more oxygen.