Smegma (
GreekGreek , an independent branch of the Indo-European family of languages, is the language of the Greeks. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. In its ancient form, it is the language of classical...
smēgma, "soap") is a combination of
exfoliatedExfoliation involves the removal of the oldest dead skin cells on the skin's outermost surface, and has been used for many years to help maintain the skin. Exfoliation is involved in the process of a facial and during body treatments at spas...
(shed)
epithelial cellsIn biology and medicine, an epithelium is a tissue composed of cells that line the cavities and surfaces of structures throughout the body. Many glands are also formed from epithelial tissue...
,
transudateTransudate is extravascular fluid with low protein content and a low specific gravity . It has low nucleated cell counts and the primary cell types are mononuclear cells: macrophages, lymphocytes and mesothelia cells. For instance, an ultrafiltrate of blood plasma is transudate...
d skin oils, and moisture. It occurs in both male and female genitalia. In males, smegma helps keep the glans moist and facilitates
sexual intercourseSexual intercourse, also known as copulation or coitus, commonly refers to the act in which the male reproductive organ enters the female reproductive tract. The two entities may be of opposite sexes or not, or they may be hermaphroditic, as is the case with snails...
by acting as a lubricant.
Both males and females produce smegma. In males, smegma is produced and accumulates under the
foreskinIn male human anatomy, the foreskin is a retractable double-layered fold of skin and mucous membrane that covers the glans penis and protects the urinary meatus when the penis is not erect...
; in females, it collects around the
clitorisThe clitoris is a sexual organ that is present only in female mammals. In humans, the visible button-like portion is located near the anterior junction of the labia minora, above the opening of the urethra and vagina. Unlike the penis, which is homologous to the clitoris, the clitoris does not...
and in the folds of the
labia minoraThe labia minora or nymphae are two longitudinal cutaneous folds on the human vulva. They are situated between the labia majora, and extend from the clitoris obliquely downward, laterally, and backward on either side of the vulval vestibule, ending between bottom of the vulval vestibule and the...
(also called the
clitoral hoodIn female human anatomy, the clitoral hood, , is a fold of skin that surrounds and protects the clitoral glans. It develops as part of the labia minora and is homologous with the foreskin in male genitals.-Variation:This is a protective hood of skin that covers the clitoral glans...
).
Glands that are located around the clitoris and the vulva secrete sebum.
Smegma (
GreekGreek , an independent branch of the Indo-European family of languages, is the language of the Greeks. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. In its ancient form, it is the language of classical...
smēgma, "soap") is a combination of
exfoliatedExfoliation involves the removal of the oldest dead skin cells on the skin's outermost surface, and has been used for many years to help maintain the skin. Exfoliation is involved in the process of a facial and during body treatments at spas...
(shed)
epithelial cellsIn biology and medicine, an epithelium is a tissue composed of cells that line the cavities and surfaces of structures throughout the body. Many glands are also formed from epithelial tissue...
,
transudateTransudate is extravascular fluid with low protein content and a low specific gravity . It has low nucleated cell counts and the primary cell types are mononuclear cells: macrophages, lymphocytes and mesothelia cells. For instance, an ultrafiltrate of blood plasma is transudate...
d skin oils, and moisture. It occurs in both male and female genitalia. In males, smegma helps keep the glans moist and facilitates
sexual intercourseSexual intercourse, also known as copulation or coitus, commonly refers to the act in which the male reproductive organ enters the female reproductive tract. The two entities may be of opposite sexes or not, or they may be hermaphroditic, as is the case with snails...
by acting as a lubricant.
Human smegma
Both males and females produce smegma. In males, smegma is produced and accumulates under the
foreskinIn male human anatomy, the foreskin is a retractable double-layered fold of skin and mucous membrane that covers the glans penis and protects the urinary meatus when the penis is not erect...
; in females, it collects around the
clitorisThe clitoris is a sexual organ that is present only in female mammals. In humans, the visible button-like portion is located near the anterior junction of the labia minora, above the opening of the urethra and vagina. Unlike the penis, which is homologous to the clitoris, the clitoris does not...
and in the folds of the
labia minoraThe labia minora or nymphae are two longitudinal cutaneous folds on the human vulva. They are situated between the labia majora, and extend from the clitoris obliquely downward, laterally, and backward on either side of the vulval vestibule, ending between bottom of the vulval vestibule and the...
(also called the
clitoral hoodIn female human anatomy, the clitoral hood, , is a fold of skin that surrounds and protects the clitoral glans. It develops as part of the labia minora and is homologous with the foreskin in male genitals.-Variation:This is a protective hood of skin that covers the clitoral glans...
).
Females
Glands that are located around the clitoris and the vulva secrete sebum. The accumulation of sebum combined with dead skin cells forms smegma. Smegma clitoridis is defined as the secretion of the apocrine glands of the clitoris, in combination with desquamating epithelial cells
Males
Smegma was originally thought to be produced by sebaceous glands near the
frenulumA frenulum is a small fold of tissue that secures or restricts the motion of a mobile organ in the body.-In human anatomy:...
called
Tyson's glandsPreputial glands are exocrine glands that are located in front of the genitals of some mammals and produce pheromones. The preputial glands of female animals are sometimes called clitoral glands....
, however subsequent studies have failed to find these glands. Wright states that smegma is produced from minute microscopic protrusions of the mucosal surface of the foreskin and that living cells constantly grow towards the surface, undergo fatty degeneration, separate off, and form smegma. Parkash
et al. found that smegma contains 26.6% fats and 13.3% proteins, which they judged to be consistent with necrotic epithelial debris. Newly produced smegma has a smooth, moist texture. It is thought to be rich in
squaleneSqualene is a natural organic compound originally obtained for commercial purposes primarily from shark liver oil, though botanic sources are used as well, including amaranth seed, rice bran, wheat germ, and olives. All higher organisms produce squalene, including humans. It is a hydrocarbon and a...
and contain prostatic and seminal secretions, desquamated epithelial cells, and the mucin content of the
urethral glands of LittréThe term urethral or periurethral gland is used to refer to any of the many glands that branch off the wall of the urethra of male mammals....
. Some state that it contains anti-bacterial enzymes such as
lysozymeLysozyme, also known as muramidase or N-acetylmuramide glycanhydrolase, are a family of enzymes which damage bacterial cell walls by catalyzing hydrolysis of 1,4-beta-linkages between N-acetylmuramic acid and N-acetyl-D-glucosamine residues in a peptidoglycan and between N-acetyl-D-glucosamine...
and hormones such as
androsteroneAndrosterone is a steroid hormone with weak androgenic activity. It is made in the liver from the metabolism of testosterone.-History:It was first isolated in 1931, by Adolf Friedrich Johann Butenandt and Kurt Tscherning...
, though others dispute this.
According to Wright, little smegma is produced during childhood, although the foreskin may contain sebaceous glands. She also says that production of smegma increases from adolescence until sexual maturity when the function of smegma for lubrication assumes its full value, and from middle-age production starts to decline and in old age virtually no smegma is produced. Oster reported that the incidence of smegma increased from 1% among 6-7 year olds to 8% among 16-17 year olds (an overall incidence of 5%).
One study found that subjects who retracted the foreskin when bathing were less likely to have smegma accumulation. An early study by Plaut and Kohn-Speyer (1947) found that horse smegma had a carcinogenic effect on mice. Heins
et al.(1958) used human smegma on mice and found a carcinogenic effect, but Reddy and Baruah (1963) were unable to reproduce this effect, concluding that if a carcinogenic effect did exist, it must be weak. In other more recent studies, smegma was found to be a risk factor among penile cancer patients. However, the
American Cancer SocietyThe American Cancer Society is the "nationwide community-based voluntary health organization dedicated to eliminating cancer as a major health problem by preventing cancer, saving lives, and diminishing suffering from cancer, through research, education, advocacy and service."The society is...
says that smegma itself is probably not carcinogenic, and a recent review concluded that "the evidence does not support the theory that smegma is a cause of genital cancer. "
Non-human Smegma
In healthy animals, smegma helps clean and lubricate the genitals. In veterinary medicine, analysis of this smegma is sometimes used for detection of urogenital tract pathogens, such as
Tritrichomonas foetusTritrichomonas foetus' is a single celled flagellated protozoan parasite that is known to be a pathogen of the bovine reproductive tract as well as the intestinal tract of cats. In cattle, the organism is transmitted to the female vagina and uterus from the foreskin of the bull where the parasite...
. Accumulation of smegma in the equine
preputial foldsIn male human anatomy, the foreskin is a retractable double-layered fold of skin and mucous membrane that covers the glans penis and protects the urinary meatus when the penis is not erect...
and the urethral fossa and urethral diverticulum can form large "beans" and promote the carriage of
Taylorella equigenitalisTaylorella equigenitalis is a Gram-negative bacterium of the genus Taylorella, and the causative agent of Contagious Equine Metritis in horses....
, the causative agent of
contagious equine metritisContagious Equine Metritis is a venereal infection of the genital tract of horses brought on by the Taylorella equigenitalis bacteria. Passed on through sexual contact, according to Robert N. Oglesby DVM, the disease was first reported in 1977 on horse breeding farms in England and was found in...
. Some equine veterinarians have recommended periodic cleaning of male genitals to improve the health of the animal.