Ever had your hairs on skin suddenly stand up? Of course you had. But all you know about it is either “Oh I’m getting chills” or “OMG that’s hilarious”. Walk through our blog that explains the minutes of Goosebumps or the Piloerection. Featuring Trivia also that will really answer some weird question of yours.
Goose bumps (Goosebumps) or medical term “Cutis anserine” is a physiological process of human body in response to cold (hypothermia) or strong emotions which causes involuntary erection of hairs. Goosebumps are also referred as Goose flesh or Goose pimples.
Origin of word
It’s not like someone plucked feathers from the goose, and the goose skin got protrusions exactly where the feathers were, but hey, it’s exactly is! The word “Goose bumps” originates from the goose protrusions on goose skin after a feather had been plucked from it. Human skin is just like that goose who faced the feather plucking, and hence the term “Goose bumps” for the humans too.
The reflex of producing goose bumps is known as horripilation, piloerection, or the pilomotor reflex. This reflex can be initiated by stimuli like Cold (hypothermia) or strong emotions like fear, nostalgia, pleasure, euphoria, awe, admiration, and sexual arousal.
Apart from this, weird causes involve when hearing plastic or metal being scratched. Indeed weird! But hey, we got explanation for that too
An important point to add is that Goose bumps can occur only in mammals, since other animals do not have hair. The term “goose bumps” is therefore misleading: the bumps on the skin of a plucked goose technically do not qualify as piloerection. Birds do however have a similar reflex of raising their feathers in order to keep warm.
Rarely, Goose bumps may be included as symptom of some diseases, such as temporal lobe epilepsy, some brain tumors, and autonomic hyper-reflexia. Goose bumps can also be caused by heroin withdrawal. A skin condition that mimics goose bumps in appearance is keratosis pilaris.
In response to the stimuli explained in the section Causes of Goose bumps, the basics of piloerection can be better understood by the following:
Stimulus initiates pilomotor reflex through sympathetic nervous system and hence causing tiny muscles at the base of each hair, known as arrector pili muscles, to contract and pull the hair erect.
In humans, goose bumps are strongest on the forearms, but also occur on the legs, back, and other areas of the skin that have hair. In some people, they even occur in the face or on the head.
In animals, these can occur throughout parts of skin covered by hair. Most important example may include Porcupines! Have a look what they look after goose bumps-
Piloerection as a response to cold or fear is vestigial in humans; as humans retain only very little body hair, the reflex (in humans) now serves no known purpose.
In animals, this may serve as heat preservation (more hairs=more insulation) or for defense as in porcupine or maybe some else.
Q1- Why not on face?
Ans- Piloerection (the muscular reflex that causes goosebumps) is found throughout the animal kingdom and is usually put to use by angry or scared animals. The piloerection causes hair to stand on its end making animals appear larger to predators and rivals.
Humans, through the course of evolution have retained comparatively very little body hair, so piloerection no longer serves much of a purpose. As such, it functions to varying degrees among people; a genetic variation similar to hair color or nose length. That’s the long way of saying, while most people do not get goosebumps on their face as it has not assisted in human evolutionary survival for quite some time, some people still do.
Q2- Why Goosebumps in scratching sounds?
Ans- The mechanism of piloerection (Goosebumps) has to do with your natural reflexes to external stimuli.
Fear and temperature both have strong effects on piloerection (Goosebumps) through autonomic nervous systems feedback systems. These are mediated like other emotion-linked autonomic reflexes by routing through the limbic system. These other emotion-linked autonomic reflexes include blushing, blanching, butterflies in the stomach.
The limbic system is the site of primitive drives: sex, fear, rage, aggression and hunger. Anatomical sites for the limbic system include amygdala, parahippocampal gyrus, uncus, subcallosal gyrus, cingulate gyrus, fornix, dentate gyrus, hypothalamus and hippocampus. These are found around a major structure called the thalamus which receives virtually all sensory input. The medial forebrain bundle is a bidirectional communication with the brainstem which then directly mediates autonomic reflexes. A second method of invoking the autonomic reflexes is through the hypothalamus which also sends nerve projections to the brainstem.
Specifically, direct stimulation of the amygdala and hypothalamus evokes the piloerection pathway. It’s in these physical structures that emotional stimulation by music or the reading of poetry, etc. can result in piloerection. So also non-pleasant and/or unexpected sounds may elicit a fight or flight reaction, which may include piloerection (goosebumps).
Q3- Can it be controlled?
Ans- Medical term clearly says- “Involuntary action”, so indeed no. But news has been that some people do control it!