Ever had the hair on the 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 questions of yours.
Goosebumps (medical term “Cutis anserine“) is a physiological process of the human body in response to cold (hypothermia) or strong emotions which causes involuntary erection of hairs.
The other term used for the same is “Piloerection” or “Horripilation“. Goosebumps are also referred to 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 exactly is!
The word “Goosebumps” 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 for humans too.
The reflex of producing goose bumps is known as horripilation, piloerection, or the pilomotor reflex. This causes contraction of the base muscles which are present at the hair follicle. These muscles are controlled by Autonomic Nervous System (ANS).
If you are not familiar with ANS, it is responsible for spontaneous functions in our body without our consciousness.
The reasons why we get goosebumps to include:
- Emotional Trigger
1. Emotional Triggers
These can include intense emotions such as excitement, fear, nostalgia, awe, euphoria, admiration, sexual arousal, and pleasure.
The simplest explanation is that the Autonomic Nervous System is involved with the processing of emotions too.
Sudden changes in temperature, such as a cold breeze or extreme chill can cause these goosebumps.
Although many people state this is related to the music evoking strong emotions, there are these weird causes involved when hearing plastic or metal being scratched. Indeed weird!
Rarely, Goosebumps may be included as a symptom of some diseases, such as temporal lobe epilepsy, some brain tumors, and autonomic hyperreflexia.
“Cutis Anserine” can also be caused by heroin withdrawal. A skin condition that mimics piloerection in appearance is keratosis pilaris.
Science behind Goosebumps
Any of the mentioned stimuli can initiate a pilomotor reflex through the sympathetic nervous system. This causes the tiny muscles at the base of each hair, known as “arrector pili muscles“, to contract and pull the hair erect.
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.
In response to the stimuli explained in the section Causes of Goosebumps, the basics of piloerection can be better understood by the following:
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. The most important example may include Porcupines! Have a look at what they look after goosebumps-
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 porcupines or maybe someone else.
Q1- Why not on the 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 faces as it has not assisted in human evolutionary survival for quite some time, some people still do.
Q2- Why do we get 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, and 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 the 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 the news has been that some people do control it!