Goose bumps, goosebumps or goose-pimples are the bumps on a person's skin at the base of body hairs which may involuntarily develop when a person is tickled,

cold Cold is the presence of low temperature, especially in the atmosphere. In common usage, cold is often a subjective perception. A lower bound to temperature is absolute zero, defined as 0.00K on the Kelvin scale, an absolute thermodynamic ...

or experiencing strong emotions such as

fear Fear is an intensely unpleasant emotion in response to perceiving or recognizing a danger or threat. Fear causes physiological changes that may produce behavioral reactions such as mounting an aggressive response or fleeing the threat. Fear ...

euphoria Euphoria ( ) is the experience (or affect) of pleasure or excitement and intense feelings of well-being and happiness. Certain natural rewards and social activities, such as aerobic exercise, laughter, listening to or making music and dan ...

or sexual arousal. The formation of goose bumps in humans under stress is considered to be a vestigial reflex. Its function in other apes is to raise the body's hair, and would have made human ancestors appear larger to scare off predators or to increase the amount of air trapped in the fur to make it more insulating. The reflex of producing goose bumps is known as piloerection or the pilomotor reflex, or, more traditionally, horripilation. It occurs in many

mammals Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fu ...

; a prominent example is porcupines, which raise their quills when threatened, or sea otters when they encounter sharks or other predators.

Anatomy and biology

Goose bumps are created when tiny muscles at the base of each hair, known as '' arrector pili muscles'', contract and pull the hair straight up. The reflex is started by the

sympathetic nervous system The sympathetic nervous system (SNS) is one of the three divisions of the autonomic nervous system, the others being the parasympathetic nervous system and the enteric nervous system. The enteric nervous system is sometimes considered part of ...

, which is responsible for many

fight-or-flight response The fight-or-flight or the fight-flight-or-freeze response (also called hyperarousal or the acute stress response) is a physiological reaction that occurs in response to a perceived harmful event, attack, or threat to survival. It was first desc ...

s. The muscle cells connected to the hair follicle have been visualized by actin immunofluorescence. Arrector pili muscle Arrector pili muscles (APM) are smooth muscles which connect the basement membrane to the hair follicle. When these muscles contract, they increase the trapping of air on the surface of the skin and in turn, causes

thermoregulation Thermoregulation is the ability of an organism to keep its body temperature within certain boundaries, even when the surrounding temperature is very different. A thermoconforming organism, by contrast, simply adopts the surrounding temperature ...

to the body. It used to be believed that each APM was connected to an individual

hair follicle The hair follicle is an organ found in mammalian skin. It resides in the dermal layer of the skin and is made up of 20 different cell types, each with distinct functions. The hair follicle regulates hair growth via a complex interaction betwe ...

. More recent studies have disproved this and now explain that there can be multiple hair follicles connected to a single APM. In between the hair follicle and the APM there are lobules which form an angular shape. These lobules are sebaceous gland lobules which are supported by the APM. PilioerectionAnimation

Hair follicle Hair follicles have four parts. There is the bulb, supra bulbar area, isthmus and infundibulum. The bulb is to be known as the part that is responsible for the growth of the rest of the hair follicle.

As a response to cold

In animals covered with fur or hair, the erect hairs trap air to create a layer of insulation. Goose bumps can also be a response to anger or fear: the erect hairs make the animal appear larger, in order to intimidate enemies. This can be observed in the intimidation displays of chimpanzees, some

New World monkey New World monkeys are the five families of primates that are found in the tropical regions of Mexico, Central and South America: Callitrichidae, Cebidae, Aotidae, Pitheciidae, and Atelidae. The five families are ranked together as the Ceboid ...

s like the

cotton-top tamarin The cotton-top tamarin (''Saguinus oedipus'') is a small New World monkey weighing less than . This New World monkey can live up to 24 years, but most of them die by 13 years. One of the smallest primates, the cotton-top tamarin is easily recog ...

,French and Snowdon.

Sexual dimorphism Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most an ...

in responses to unfamiliar intruders in the tamarin, '' Saguinus oedipus''. Animal Behaviour (1981) vol. 29 (3) pp. 822–829 in stressed mice and rats, and in frightened cats.

In humans

In humans, goose bumps can even extend to piloerection as a reaction to hearing nails scratch on a chalkboard, listening to awe-inspiring music, or feeling or remembering strong and positive emotions (e.g., after winning a sports event), or while watching a

horror film Horror is a film genre that seeks to elicit fear or disgust in its audience for entertainment purposes. Horror films often explore dark subject matter and may deal with transgressive topics or themes. Broad elements include monsters, apo ...

Some can deliberately evoke goose bumps in themselves without any external trigger. Such people tend to have the ability to increase their heart-rate and describe the event as a chill from the base of their skull down the body, that causes the increase in heart-rate and concurrent goose bumps on the skin especially the forearms which varies in duration. Further research is needed to discover more on such people. Goose bumps are accompanied by a specific physiological response pattern that is thought to indicate the emotional state of being moved. In humans, goose bumps are strongest on the forearms, but also occur on the legs, neck, and other areas of the skin that have hair. In some people, they even occur in the face or on the head. Piloerection is also a classic symptom of some diseases, such as temporal lobe epilepsy, some

brain tumor A brain tumor occurs when abnormal cells form within the brain. There are two main types of tumors: malignant tumors and benign (non-cancerous) tumors. These can be further classified as primary tumors, which start within the brain, and secon ...

s, and autonomic hyperreflexia. Goose bumps can also be caused by withdrawal from

opiate An opiate, in classical pharmacology, is a substance derived from opium. In more modern usage, the term ''opioid'' is used to designate all substances, both natural and synthetic, that bind to opioid receptors in the brain (including antagonist ...

s such as heroin. A skin condition that mimics goose bumps in appearance is keratosis pilaris.

Causes

Extreme temperatures

Goose bumps 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 ( arrector pili muscle) attached to each

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.

Intense emotion

People often say they feel their "hair standing on end" when they are frightened or in awe. 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

floods the blood with adrenaline (epinephrine), a hormone that speeds up heart-rate,

metabolism Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run c ...

, 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 force the hair up.

Music

Canadian researchers have suggested that when humans are moved by music, their brains behave as if reacting to delicious

food Food is any substance consumed by an organism for nutritional support. Food is usually of plant, animal, or fungal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals. The substance is ...

, psychoactive

drugs A drug is any chemical substance that causes a change in an organism's physiology or psychology when consumed. Drugs are typically distinguished from food and substances that provide nutritional support. Consumption of drugs can be via inhalat ...

, or

money Money is any item or verifiable record that is generally accepted as payment for goods and services and repayment of debts, such as taxes, in a particular country or socio-economic context. The primary functions which distinguish money ar ...

. The pleasure experience is driven by the chemical

dopamine Dopamine (DA, a contraction of 3,4-dihydroxyphenethylamine) is a neuromodulatory molecule that plays several important roles in cells. It is an organic chemical of the catecholamine and phenethylamine families. Dopamine constitutes about 8 ...

, which produces physical effects known as "chills" that cause changes in heart-rate,

breathing Breathing (or ventilation) is the process of moving air into and from the lungs to facilitate gas exchange with the internal environment, mostly to flush out carbon dioxide and bring in oxygen. All aerobic creatures need oxygen for cell ...

, 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 have 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

scientist A scientist is a person who conducts scientific research to advance knowledge in an area of the natural sciences. In classical antiquity, there was no real ancient analog of a modern scientist. Instead, philosophers engaged in the philosophica ...

Ingestion

Medications and herbal supplements that affect body temperature and blood flow may cause piloerection. For example, one of the common reported side effects of the intake of yohimbine is piloerection.

Opiate withdrawal

Piloerection is one of the signs of opioid withdrawal. The term " cold turkey" meaning abrupt withdrawal from a drug, may derive from the goose bumps that occur during abrupt withdrawal from

opioid Opioids are substances that act on opioid receptors to produce morphine-like effects. Medically they are primarily used for pain relief, including anesthesia. Other medical uses include suppression of diarrhea, replacement therapy for opioi ...

s; this resembles the skin of a refrigerated plucked turkey.

Voluntary control

An unknown proportion of people may consciously initiate the sensation and physiological signs of piloerection. The phenomenon is discovered spontaneously, appearing to be innate, and is not known to be possible to learn or acquire. Those with the ability frequently are unaware that it is not possible for everyone. The ability appears to correlate with personality traits associated with openness to experience.

Primate heritage hypothesis

People often experience goose bumps as a reaction to the sound of fingernails being dragged across a chalkboard. In 2006 Vanderbilt psychologist Randolph Blake conducted a study to find out why people react that way to the sound. He noted that the core sound causing the reaction was acoustically similar to that of a primate distress call.

Etymology

The term "goose bumps" derives from the phenomenon's association with goose skin. Goose feathers grow from pores in the epidermis that resemble human

s. When a goose's feathers are plucked, its skin has protrusions where the feathers were, and these bumps are what the human phenomenon resembles. It is not clear why the particular fowl, goose, was chosen in English (and German, Greek, Italian, Swedish, Danish, Norwegian, Polish and Czech) Translations for ''goose-bumps'' in English wiktionary as most other birds share this same anatomical feature. Other languages may use a different species. For example, the hen or chicken is used in Vietnamese, Korean, Japanese, Finnish, Dutch, Luxembourgish, French, Spanish, Portuguese and Galician; Irish uses both; Hebrew, the duck; the ants (referred to as "''murashki''", alluding to the feeling of ants crawling on ones skin) in Ukrainian and Russian; and a variety of synonyms in Mandarin. Some authors have applied "goose bumps" to the symptoms of sexually transmitted diseases. "Bitten by a Winchester goose" was a common euphemism for having contracted syphilis in the 16th century. " Winchester geese" was the nickname for the prostitutes of Southern London, licensed by the

Bishop of Winchester The Bishop of Winchester is the diocesan bishop of the Diocese of Winchester in the Church of England. The bishop's seat ('' cathedra'') is at Winchester Cathedral in Hampshire. The Bishop of Winchester has always held '' ex officio'' (except ...

in the area around his London palace.

References

External links

{{DEFAULTSORT:Goose Bumps Skin physiology Reflexes