Author: Jana Vasković MD•Reviewer: Dimitrios Mytilinaios MD, PhD
Last reviewed: July 06, 2022
Reading time: 11 minutes
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Sweat gland
Glandula sudorifera
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Synonyms: Sudoriferous gland, Eccrine sweat gland, show more...
The sweat glands are exocrine glands distributed throughout the body surface. They are sometimes referred to as sudoriferous or sudoriparous glands. These names are derived from the latin word ‘sudor’ which means ‘sweat’. There are two types of sweat glands:
- Eccrine glands are found all over the body and secrete a watery product that cools the skin.
- Apocrine sweat glands are mainly found in the armpits and perianal area, and secrete a more viscous, odorous product.
There are several histological differences between these two types of glands, but they do share a common general structure. That is, they both consist of a secretory and duct (excretory) segments.
This article will discuss the histology and functions of the sweat glands.
| Definition | Exocrine glands that produce sweat, located within the dermis/subcutis of the skin. |
| Types | Eccrine glands Apocrine glands |
| Eccrine glands | Simple coiled glands whose watery excretion aids thermoregulation by evaporating from the body surface, thus cooling the body. |
| Apocrine glands | Simple tubular glands whose excretion contributes to body odor. |
Contents
- Basic structure
- Eccrine sweat glands
- Secretory segment
- Duct segment
- Function
- Apocrine sweat glands
- Secretory segment
- Duct segment
- Functions
- Clinical notes
- Sources
+ Show all
Basic structure
In general, sweat glands tend to comprise a secretory unitwhich is located either in the deep dermis or in the subcutaneous tissue, and a ductwhich continues from the secretory unit towards the body surface, through which sweat or secretory product is passed.
The secretory units of sweat glands are surrounded by contractile myoepithelial cells which act to help secrete the gland’s product. The contraction of these cells are either controlled by hormones or nerve action.
Sweat glands open into the skin’s surface, or in the case of apocrine sweat glands, into hair follicles. The part of the gland that opens onto the skin or hair follicle is known as the acrosyringium. Whilst sweat glands share a basic structure, apocrine and eccrine sweat glands have many differences which are outlined during the rest of this article.
Sweat glands Explore study unit
Eccrine sweat glands
Eccrine sweat gland
Glandula sudorifera eccrina
Synonyms: Glandula sudorifera merocrina
The eccrine glands are simple coiled glands whose main function is to help in regulating the temperature of the body. They secrete hypotonic solution, i.e. the sweat, whose evaporation helps cooling the body. In the process of producing the sweat, the eccrine glands reabsorb a certain amount of sodium and water, which is why the sweat is hypotonic. With sweat, we excrete ammonia, urea, uric acid and sodium chloride.
In contrast to the apocrine glands, the eccrine glands are not related to the hair follicle, but instead exist as independent structures located in the skin of the whole body, except for the lips and external genitals.
Eccrine glands consist of two segments: secretory and duct. The secretory segment is found in the deep dermis or in the superficial part of the subcutaneous tissue. The duct segment is continuous with the secretory, coiling from it towards the surface of the skin.
Secretory segment
Clear cells
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Synonyms: C cells
The secretory segment consists of three types of cells that lie on the basal lamina: clear, dark and myoepithelial. The clear and dark cells are the secretory cells, while the myoepithelial are the contractile cells. Given the different sizes of cells, the lining of the secretory segment resembles to the pseudostratified epithelium.
- The clear cells contain large amounts of glycogen, numerous smooth endoplasmic reticula and mitochondria, as well as a small Golgi apparatus. The function of these cells is to produce the electrolytes watery component of sweat.
- The dark cells contain numerous rough endoplasmic reticula and a well-developed Golgi apparatus. This is because they produce the glycoprotein component of the sweat. These components are packed within secretory granules which are usually found aggregated in the apical cytoplasm.
- The myoepithelial cells are contractile cells, usually dispersed between the clear and dark cells. They are filled with contractile filaments and their contraction promotes fast excretion of sweat.
Duct segment
Basal cell layer of duct
Epitheliocyti basales
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The duct segment continues from the secretory segment and goes towards the skin surface. After leaving the dermis, it exhibits slight coiling in course. It is lined by the stratified cuboidal epithelium which has two layers: basal or peripheral layer which is deep, and luminal or apical layer which lies on top of the basal layer. It is important to note that the duct segment does not contain myoepithelial cells.
The basal cells have an ellipsoid nucleus with a prominent nucleolus, as well as a large amount of ribosomes and mitochondria. The luminal cells have smaller nucleus than basal. Their most distinguishing feature is the presence of glassy or hyalinized structure in their cytoplasm, which represents accumulated tonofilaments.
Custom quiz: Integumentary system For a broader topic focus, try this customizable quiz.
Function
The eccrine glands are responsible for thermoregulatory sweating. Simply said, when the ambient temperature is too high, these glands release sweat which then evaporates and conveys the heat from the body. This type of physiological sweating first starts in the skin of the scalp and forehead, then to the face and the rest of the skin. The last regions to exhibit the thermoregulatory sweating are palms and soles.
In contrast to thermoregulatory sweating, there is also sweating induced by the emotional stress. In this situation, the palms, soles and axillae are the first regions to sweat.
The nervous stimulation for thermoregulatory and stress sweating is different. The thermoregulatory sweating is stimulated by the cholinergic input, whereas the stress sweating is promoted by the adrenergic input.
Apocrine sweat glands
Apocrine sweat gland
Glandula sudorifera apocrina
The apocrine glands are coiled tubular sweat glands associated with the hair follicles of the skin.They are found in the skin of axilla, areola, nipples, perianal skin and the skin of external genitals.
The apocrine glands secrete a viscous, oily substance, that is yellow in color, and has an acrid odor. This secretion is produced in response to the presence of bacterial decomposition. Apocrine sweat glands are controlled by sex hormones and therefore only become active at puberty. In contrast to the eccrine glands, there is no reabsorption or any modification of the excretory product whatsoever in the apocrine glands.
They also consist of a secretory and a duct segments.
Secretory segment
The secretory portion is usually located in the superficial layer of the subcutis, however it can sometimes be found in the deep dermis. There are a couple of histological characteristics which differ the secretory segment of apocrine glands from that of the eccrine glands:
- The secretory part of apocrine glands is much wider than that of the eccrine glands.
- The apocrine glands store their product in their lumina, while as we noted before, the eccrine glands store them in the granules within the apical cytoplasm of their cells.
The secretory segment of apocrine glands is lined by simple epithelium which consists of only one cell type. These cells appear eosinophilic and they feature a protrusion on their apical region. It was believed that the separation of this protrusion from the cell is the mechanism of excretion of cellular product. This is why the glands bear the name apocrine, derived from the word apex which means "the tip", suggesting that the pinching of the tip is the way of excretion. However, recent studies have proven that this is not true. Instead, the cells pack their products in small granules, which then reach the lumen through the process of exocytosis. This way of secretion is called merocrine secretion.
The cells are also rich in lysosomes, mitochondria and lipofuscin and feature a prominent Golgi apparatus, especially when the secretion phase is active.
Myoepithelial cells are also dispersed throughout the lining of the secretory segment. Their function is to aid excretion with their contractions.
Duct segment
The duct of apocrine glands has a narrow lumen and a relatively straight course towards the hair follicle where it opens. It is lined by the stratified cuboidal epithelium which is devoid of myoepithelial cells.
The epithelium usually consists of 2-3 cell layers. The cells of the luminal layer, which is the most superficial one, contain glassy aggregation in their apical cytoplasm, which, similar to that of eccrine glands, represents the aggregation of tonofilaments.
Functions
The activity of the apocrine glands heavily depends on sex hormones. In other mammals, these glands release a significant amount of pheromones which affects the odour and 'chemical fingerprint' of an animal. It is considered that the odour plays an important role in sexual pairing and social treatment of an animal.
Although in humans the product of apocrine glands also affects the body odor, its social and sexual significance is consider as rudimentary to non-existent.
Clinical notes
Sweat gland dysfunction can lead to a variety of abnormalities and diseases. For example, inflammation of the apocrine sweat glands can lead to the rare diseases known as Fox-Fordyce disease. This causes a persistent rash in the pubic regions and armpits, and is more common in women. Moreover, if the eccrine glands become exhausted due to excessive activity, this can contribute to heatstroke. This in turn can result in hyperpyrexia, which is categorised as an extreme rise in body temperature that can potentially be fatal.
Additionally, the sweat glands can be linked to cystic fibrosis. Eccrine sweat glands usually reabsorb sodium and chloride ions through their ductal epithelium, which causes sweat to be hypotonic. This process is controlled by the hormone aldosterone. However, if defective chloride ion reabsorption occurs, this can lead to parents noticing that a child has salty skin when kissing the child. This acknowledgement leads them to the doctor which usually ends up in a diagnosis of cystic fibrosis. The sweat glands of people with cystic fibrosis appear to be histologically normal, however, they have saltier sweat due to overproduction of sodium and chloride. This issue is related to a protein known as cystic fibrosis transmembrane regulator (CFTR), which is is genetically coded for. Cystic fibrosis a result of a recessive gene meaning that both parents must supply a copy of the defective gene to their child for the disease to occur.
Sources
All content published on Kenhub is reviewed by medical and anatomy experts. The information we provide is grounded on academic literature and peer-reviewed research. Kenhub does not provide medical advice. You can learn more about our content creation and review standards by reading our content quality guidelines.
References:
- Ross, M. H., PhD, & Pawlina, W., MD. (2015). Histology: A Text and Atlas: With Correlated Cell and Molecular Biology (7de editie). Lippincott Williams & Wilkins.
- Mescher, A. (2013). Junqueira’s Basic Histology: Text and Atlas, Thirteenth Edition (13 ed.). McGraw-Hill Education / Medical.
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FAQs
What is the structure of sweat gland? ›
Eccrine sweat glands occur over most of the body and open directly onto the skin's surface. Apocrine glands open into the hair follicle, leading to the surface of the skin. Apocrine glands develop in areas with many hair follicles, such as on the scalp, armpits and groin.
What is the function of sweat gland? ›sweat gland, either of two types of secretory skin glands occurring only in mammals. The eccrine sweat gland, which is controlled by the sympathetic nervous system, regulates body temperature. When internal temperature rises, the eccrine glands secrete water to the skin surface, where heat is removed by evaporation.
What is the function of sweat glands quizlet? ›-function: Very important and highly efficient part of the body's heat regulating system. The gland is supplied with nerve endings that cause them to secrete sweat when body temperature is high. When the dry sweat evaporates off the skin surface, large amounts of body heat are carried with it.
What is the structure of eccrine sweat glands? ›Each eccrine gland is a single tubular structure, about 3–5 mm in length in humans with a secretory coil below a relatively straight sweat duct (Fig. 1) (17). The secretory coil contains three types of cells – dark, clear and myoepithelial – identifiable by conventional microscopy in humans.
What is the function of the sweat glands and where are they located? ›Sweat is produced by glands in the deeper layer of the skin, the dermis. Sweat glands occur all over the body, but are most numerous on the forehead, the armpits, the palms and the soles of the feet. Sweat is mainly water, but it also contains some salts. Its main function is to control body temperature.
Which structure is a type of sweat gland quizlet? ›Structure A produces sebum, an oily secretion that coats the hairs and prevents infectious agents from penetrating the hair shaft. Which structure is a type of sweat gland? Structure C is an eccrine gland, the most abundant type of sweat (sudoriferous) gland.
What is the anatomy and physiology of sweat glands? ›Sweat glands are appendages of the integument. There are eccrine and apocrine sweat glands. They differ in embryology, distribution, and function. Eccrine sweat glands are simple, coiled, tubular glands present throughout the body, most numerously on the soles of the feet.
What is the most important sweat gland? ›Eccrine sweat glands are the most numerous, distributed across nearly the entire body surface area, and responsible for the highest volume of sweat excretion [5]. By contrast, apocrine and apoeccrine glands play a lesser role in overall sweat production as they are limited to specific regions of the body [7–10].
What is the function of sweat glands and sebaceous glands? ›Both sebaceous glands and sweat glands are organs in your body that protect your skin from becoming too dry. Sebaceous glands produce an oily substance called sebum and sweat glands produce a watery substance called sweat. Sweat glands have ducts, which are pathways to excrete substances to the surface of your skin.
What is a sweat gland quizlet? ›sudoriferous glands(sweat Glands) glands that secrete sweat to the outside of the body(sweat glands); also assist in body temperature regulation. sudoriferous glands (sweat glands) Sweat is produced when the body is hot or stressed, and as the sweat evaporates the skin cooled.
How does sweat glands maintain body temperature? ›
That's because cooling your body via sweating relies on a principle of physics called "heat of vaporization." It takes energy to evaporate sweat off of your skin, and that energy is heat. As your excess body heat is used to convert beads of sweat into vapor, you start to cool down.
What type and shape are sweat glands? ›The sweat glands are simple tubular exocrine glands that are found in the superficial hypodermis bordering on the dermis.
What is the function of eccrine and apocrine glands? ›In humans, sweat glands generally are found as two types, (1) eccrine and (2) apocrine. Eccrine-gland sweat allows the body to control its internal temperature in response to thermal stress. Apocrine gland function is more obscure but likely includes pheromone production.
What is the structure of the apocrine sweat gland? ›Apocrine sweat glands are tubular, coiled secretory glands lined by simple cuboidal epithelium that surround a larger lumen than eccrine sweat glands. Within the basal region, they contain myoepithelial cells with contractile properties that assist in the movement of secretory products upward and outward.
What is sweat composed of? ›Sweat is a liquid made from 99% water and 1% salt and fat. Up to a quart of sweat evaporates each day. When your body becomes overheated, you sweat more. The evaporation of sweat from your skin cools your body down.
What layer are sweat glands located? ›Your dermis contains collagen and elastin, which help make your dermis thick and supportive of your skin's overall structure. All of your connective tissues, nerve endings, sweat glands, oil glands and hair follicles exist in your dermis.
Where are sweat glands located in the skin layer? ›Sweat Gland (Sudoriferous Gland)
These glands are located in the epidermis and produce moisture (sweat) that is secreted through tiny ducts onto the surface of the skin (stratum corneum). When sweat evaporates, skin temperature is lowered.
Introduction. Sudoriferous glands, also known as sweat glands, are either of two types of secretory skin glands, eccrine or apocrine. Eccrine and apocrine glands reside within the dermis and consist of secretory cells and a central lumen into which material is secreted.
What is the physiology of sweat? ›When the body temperature rises, the sympathetic nervous system stimulates the eccrine sweat glands to secrete water to the skin surface, where it cools the body by evaporation. Thus, eccrine sweat is an important mechanism for temperature control.
Which hormone is responsible for sweating? ›Increased adrenaline stimulates the apocrine glands for sweating. The hormone epinephrine can cause both vasoconstriction and vasodilation.
What hormone causes sweating? ›
The thyroid produces too much thyroid hormone, thyroxine. The body then ramps up its metabolism, causing sweating, rapid heartbeat, weight loss and other symptoms.
What are sweat glands simple? ›sweat gland. noun. : a gland of the skin that gives off perspiration and opens by a tiny pore in the skin.
What is the function of sweat gland Brainly? ›The primary function of these glands is to regulate the function of the body. For example, if the weather is too hot outside the body temperature increases then the sweat glands release Sweat or Perspiration from the body which in turn cools the body down.
What causes sweat glands? ›The nervous system automatically triggers sweat glands when your body temperature rises. Sweating also occurs, especially on your palms, when you're nervous. Primary hyperhidrosis is caused by faulty nerve signals that trigger eccrine sweat glands to become overactive.
Why do we sweat when we sleep? ›Your sleepwear and sleep environment
But, sometimes, there's a fine line between being cozy and overheating. Dr. Ram says that the most common reason for night sweats are: Bedding, sleepwear or even a mattress that doesn't "breathe" A sleep environment that's too warm.
Introduction. Accessory structures of the skin include the hair, nails, sweat glands and sebaceous glands. These structures embryologically originate from the epidermis and are often termed “appendages”; they can extend down through the dermis into the hypodermis.
What cells are sweat glands? ›There are three types of cells in the secretory coil: clear cells, dark cells, and myoepithelial cells. Myoepithelial cells provide power support for sweat secretion and support the glands mechanically (Sato, 1977; Sato et al., 1989).
What structure contains sweat and oil glands? ›The dermis contains nerve endings, sweat glands and oil glands (sebaceous glands), hair follicles, and blood vessels.
What is the difference between sebaceous eccrine and apocrine glands? ›Regarding the location where their ducts release their product, the ducts of sebaceous glands, in most cases, and apocrine sweat glands excrete their products into the hair follicle canal, and the eccrine sweat glands excrete directly onto the skin surface.
What controls apocrine sweat glands? ›The apocrine sweat glands, associated with the presence of hair in human beings (as on the scalp, the armpit, and the genital region), continuously secrete a concentrated fatty sweat into the gland tube. Emotional stress stimulates contraction of the gland, expelling its contents.
What is the function of eccrine sweat glands quizlet? ›
Eccrine glands cool the body; apocrine glands function as scent glands. The skin can decrease body temperature in 2 ways. 1. It can increase evaporative heat loss by increasing sweat production by eccrine glands.
What type of tissue is sweat gland? ›The sweat glands are simple tubular exocrine glands that are found in the superficial hypodermis bordering on the dermis. They discharge their contents onto the surface of the skin via coiled secretory ducts (see the diagram opposite). The ducts open out onto epidermal ridges at a sweat pore.
What type of epithelial tissue is sweat gland? ›Sweat glands are simple tubular glands lined by cuboidal epithelium. The secretory portion of the gland lies deep in the dermis, where the tubule is twisted into a fairly compact tangle.
What cells make up sweat glands? ›There are three types of cells in the secretory coil: clear cells, dark cells, and myoepithelial cells. Myoepithelial cells provide power support for sweat secretion and support the glands mechanically (Sato, 1977; Sato et al., 1989).
What cells are in sweat glands? ›The secretory segment consists of three types of cells that lie on the basal lamina: clear, dark and myoepithelial. The clear and dark cells are the secretory cells, while the myoepithelial are the contractile cells.
Do sweat glands have cells? ›Sweat glands mainly consist of secretory and ductal portions, the latter of which comprises epidermal, straight, and coiled ducts. The secretory portion consists of secretory luminal cells and encompassing myoepithelial cells, while the ductal portion consists of luminal cells and basal cells (Fig. 1).
What are the characteristics of sweat glands? ›They differ in embryology, distribution, and function. Eccrine sweat glands are simple, coiled, tubular glands present throughout the body, most numerously on the soles of the feet. Thin skin covers most of the body and contains sweat glands, in addition to hair follicles, hair arrector muscles, and sebaceous glands.
What are the 3 accessory structures? ›Accessory structures of the skin include hair, nails, sweat glands, and sebaceous glands.
What hormone produces sweat? ›The stimulus for the secretion of apocrine sweat glands is adrenaline, which is a hormone carried in the blood. The secretion of medullary epinephrine and norepinephrine is controlled by a neural pathway that originates from the hypothalamus in response to danger or stress (the SAM pathway).
How are sweat glands activated? ›Eccrine sweat glands primarily respond to thermal stimuli; particularly increased body core temperature [40], but skin temperature and associated increases in skin blood flow also play a role [9,46–49].
What is the structure and function of sweat glands and sebaceous glands? ›
Both sebaceous glands and sweat glands are organs in your body that protect your skin from becoming too dry. Sebaceous glands produce an oily substance called sebum and sweat glands produce a watery substance called sweat. Sweat glands have ducts, which are pathways to excrete substances to the surface of your skin.
What is the role of sweat glands in maintaining body temperature homeostasis? ›Sweating plays an important role in the regulation of human body temperature through dissipating thermal energy from the skin surface when water in the sweat evaporates. Sweat counteracts heat stress after we exercise and allows us to survive in extreme climates.