Lots of things can make
our hair stand on end, from a cool breeze tickling our neck to a sense of
impending danger. We might also experience goosebumps when we hear an
inspirational speech or song. Some unrelated events elicit goosebumps. The
reason for this is the physiology of emotions!
Centuries ago, people believed that
goosebumps made our hair grow faster. Today, we know this is not the case, but
goosebumps still hold some mystery.
When we’re cold, or we experience a
strong emotion, such as fear, shock, anxiety, sexual arousal or even
inspiration, goosebumps can suddenly pop up all over the skin.
Goosebumps occur when the arrector pili
muscles cause the hairs to stand up, making the skin look bumpy. The arrector pili are
smooth, involuntary muscles that a person cannot voluntarily contract. Hence,
people cannot voluntarily cause their goosebumps. When the hairs stand up on
the skin, it is known as piloerection. Goosebumps are an involuntary reaction
to certain kinds of stimulation.
In a new study, Harvard
University scientists have discovered the reason: the cell types that cause
goosebumps are also important for regulating the stem cells that regenerate the
hair follicle and hair. Underneath the skin, the muscle that contracts to
create goosebumps is necessary to bridge the sympathetic nerve's connection to
hair follicle stem cells. The sympathetic nerve reacts to cold by contracting
the muscle and causing goosebumps in the short term, and by driving hair
follicle stem cell activation and new hair growth over the long term.
Published in the journal Cell,
these findings in mice give researchers a better understanding of how different
cell types interact to link stem cell activity with changes in the outside
environment.
These bumps are caused
by a contraction of miniature muscles that are attached to each hair. Each
contracting muscle creates a shallow depression on the skin surface, which
causes the surrounding area to protrude. The contraction also causes the hair
to stand up whenever the body feels cold. In animals with a thick hair coat, this rising of hair expands the layer of air that serves as insulation. The
thicker the hair layer, the more heat is retained. In people, this reaction is
useless because we do not have a hair coat, but goosebumps persist
nevertheless.
The medical terms
for goosebumps are piloerection, cutis anserina, and horripilation. The term
“goosebumps” is most widely used because it’s easy to remember: The little
bumps that form on your skin when this phenomenon happens.
The presence of
goosebumps with piloerection on the skin tends to suggest that a person is
cold, scared, or having an emotionally intense experience. Neurological,
endocrine, or other systemic issues may cause this symptom, so people should
see a doctor for any unusual or worrisome
goosebumps.
In addition to cold, the hair
will also stand up in many animals when they feel threatened--in a cat being
attacked by a dog, for example. The elevated hair, together with the arched
back and the sideward position the animal often assumes, makes the cat appear
bigger in an attempt to make the dog back off.
People also tend to experience goosebumps during emotional situations, such
as walking down the aisle during their wedding, standing on a podium and
listening to a national anthem after winning in sports or even just watching
horror movies on television. Quite often a person may get goosebumps many years
after a significant event, just by thinking about the emotions she once
experienced, perhaps while listening to the romantic song to which she danced
many years ago with the love of her
life.
The reason for all these responses is the subconscious release of a stress
hormone called adrenaline. Adrenaline, which in humans is produced in two small
beanlike glands that sit atop the kidneys, not only causes the contraction of
skin muscles but also influences many other body reactions. In animals, this
hormone is released when the animal is cold or facing a stressful situation,
preparing the animal for a flight-or-fight reaction. In humans, adrenaline is
often released when we feel cold or afraid, but also if we are under stress and
feel strong emotions, such as anger or excitement. Other signs of adrenaline
release include tears, sweaty palms, trembling hands, an increase in blood
pressure, a racing heart or the feeling of 'butterflies' in the stomach.
Factors trigger goosebumps
Goosebumps appear when the arrector pili muscles
contract, pulling the hairs into an upright position. On areas of the body that
do not have much hair or that only have light hair, a person might notice only
the erect hair follicle and not the hair itself. Erect hair follicles look swollen
and slightly bigger than usual. This enables them to hold the hair upright, and
it also causes goosebumps. A number of specific factors can give rise to
goosebumps. These include;
Extreme temperatures: Chills and cold: Goosebumps play an essential role in the body’s ability to regulate its
temperature. Other mammals, including humans’ primate ancestors, have thick
hair that keeps them warm. When the hair stands up, it offers more
insulation.
Many people notice goosebumps when they are cold.
They may also appear when someone thinks about being cold, such as when they
witness a cold scene in a movie. Some people also get goosebumps when they have
chills that they associate with an illness or fever. Goosebumps can be
experienced in the presence of flash-cold temperatures, for example, being in a
cold environment, and the skin being able to re-balance its surface temperature
quickly. The stimulus of cold surroundings causes the tiny muscles attached to
each hair follicle to contract. This contraction causes the hair
strands to stand straight, the purpose of which is to aid in quicker drying via
evaporation of water clinging to the hair which is moved upward and away from
the skin.
Emotionally intense experiences: Some emotionally intense experiences cause the body
to release certain chemicals that can trigger goosebumps.
In an extremely stressful situation,
the body can employ the "fight or flight"
response. As the body prepares itself for either fighting or running, the sympathetic nervous system floods
the blood with adrenaline (epinephrine), a
hormone that speeds up heart rate, metabolism,
and body temperature in the presence of extreme stress. Then the sympathetic
nervous system also causes the piloerection reflex, which makes the muscles
attached to the base of each hair follicle contract and forces the hair up.
Likewise, intensely pleasurable experiences, such as listening to music or
the gentle touch of a loved one,
can cause the brain to release dopamine. Dopamine is a chemical that plays a
role in motivation, reward, and pleasure. Experiences such as this can also
cause goosebumps.
Music:
Canadian researchers have suggested that when humans
are moved by music their brains behave as if reacting to delicious food,
psychoactive drugs,
or money. The
pleasure experience is driven by the chemical dopamine,
which produces physical effects known as "chills" that cause changes
in heart rate, breathing, temperature and the
skin's electrical conductance. The responses correlate with the degree to which
people rate the "pleasurability" of music. Dopamine release is
greatest when listeners had a strong emotional response to music. "If
music-induced emotional states can lead to dopamine release, as our findings
indicate, it may begin to explain why musical experiences are so valued,” wrote
the scientists.
Ingestion: Medications
and herbal supplements that affect body temperature and blood flow may cause
piloerection. For example, one of the commonly reported side effects of the
intake of yohimbine is piloerection.
Drugs:
Certain
drugs may also cause goosebumps. For example, a 2016 study identified two sisters who experienced goosebumps after taking a medication called milnacipran hydrochloride. Taking drugs
that stimulate activity similar to those chemicals in the body that normally
cause goosebumps may also trigger the phenomenon. For example, a person
experiencing an adrenaline-like rush when using methamphetamine may also have goosebumps. Withdrawal from some drugs, such as opioids, may also cause goosebump.
Opiate withdrawal: Piloerection
is one of the signs of opioid withdrawal. The term "cold
turkey" meaning an abrupt withdrawal from a drug, may derive from the
goosebumps that occur during abrupt withdrawal from opioids; this
resembles the skin of a refrigerated
plucked turkey.
Voluntary control: Scientists
generally agree that, in normal circumstances, goosebumps are involuntary. This
is because the arrector pili muscles, which cause goosebumps, are smooth
muscles. People cannot typically control smooth muscles, unlike skeletal
muscles, which they voluntarily use, for example, to move their legs and flex
their arms. However, there is some limited evidence to suggest that a small
number of people may be able to exert control over the arrector pili muscles.
This enables them to trigger goosebumps voluntarily. A
2018 analysis details a few cases of people who supposedly have
control over their goosebump reaction. It seemed that none of the people with
this ability learned it via conditioning or training, and doctors do not know
what causes it.
Post-mortem
goosebumps: After a person dies,
the chemical adenosine triphosphate, which provides the energy to cells,
depletes, and lactate builds up in the muscles. This process causes the muscles
to stiffen, thereby triggering rigour mortis. As part of rigour mortis, the
arrector pili muscles also stiffen, giving rise to goosebumps, in most
cases, goosebumps are nothing more than a temporary nuisance. However,
goosebumps can be a sign of a long-lasting or serious medical condition. For
example, goosebumps can also be a sign of:
Thank you Aleesha miss for revealing the mystery behind goosebumps..
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