Smegma (from

Ancient Greek Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek ...

) is

shed A shed is typically a simple, single-storey (though some sheds may have two or more stories and or a loft) roofed structure, often used for storage, for hobby, hobbies, or as a workshop, and typically serving as outbuilding, such as in a bac ...

skin cells, skin oils, and moisture that occurs in male and female mammalian genitalia. In males, smegma collects under the

foreskin In male Human body, human anatomy, the foreskin, also known as the prepuce (), is the double-layered fold of Human skin, skin, Mucous membrane, mucosal and Muscle tissue, muscular tissue at the distal end of the human penis that covers the glans ...

; in females, it collects around the

clitoris In amniotes, the clitoris ( or ; : clitorises or clitorides) is a female sex organ. In humans, it is the vulva's most erogenous zone, erogenous area and generally the primary anatomical source of female Human sexuality, sexual pleasure. Th ...

and in the folds of the labia minora.

Females

The accumulation of

sebum A sebaceous gland or oil gland is a microscopic exocrine gland in the skin that opens into a hair follicle to secrete an oily or waxy matter, called sebum, which lubricates the hair and skin of mammals. In humans, sebaceous glands occur ...

combined with dead skin cells forms smegma. ''Smegma clitoridis'' is defined as the secretion of the

apocrine Apocrine () is a term used to classify the mode of secretion of exocrine glands. In apocrine secretion, secretory cells accumulate material at their apical ends, often forming blebs or "snouts", and this material then buds off from the cells ...

(sweat) and sebaceous (sebum) glands of the clitoris in combination with desquamating epithelial cells. Glands that are located around the clitoris, the labia minora, and the labia majora secrete

. If smegma is not removed frequently it can lead to clitoral adhesion which can make clitoral stimulation (such as masturbation) painful (clitorodynia).

Males

In males, smegma helps keep the

glans The glans (, : glandes ; from the Latin word for "acorn") is a vascular structure located at the tip of the penis in male mammals or a homologous genital structure of the clitoris in female mammals. Structure The exterior structure of the g ...

moist and facilitates

sexual intercourse Sexual intercourse (also coitus or copulation) is a sexual activity typically involving the insertion of the Erection, erect male Human penis, penis inside the female vagina and followed by Pelvic thrust, thrusting motions for sexual pleasure ...

by acting as a lubricant. Smegma was originally thought to be produced by

sebaceous gland A sebaceous gland or oil gland is a microscopic exocrine gland in the skin that opens into a hair follicle to secrete an oily or waxy matter, called sebum, which lubricates the hair and skin of mammals. In humans, sebaceous glands occur in ...

s near the frenulum called Tyson's glands; however, subsequent studies have failed to find these glands. Joyce 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

squalene Squalene is an organic compound. It is a triterpene with the formula C30H50. It is a colourless oil, although impure samples appear yellow. It was originally obtained from shark liver oil (hence its name, as '' Squalus'' is a genus of sharks). ...

and contain prostatic and seminal secretions, desquamated

epithelial cells Epithelium or epithelial tissue is a thin, continuous, protective layer of cells with little extracellular matrix. An example is the epidermis, the outermost layer of the skin. Epithelial ( mesothelial) tissues line the outer surfaces of man ...

, and the mucin content of the urethral glands of Littré. Smegma contains cathepsin B, lysozymes, chymotrypsin, neutrophil elastase and

cytokines Cytokines () are a broad and loose category of small proteins (~5–25 kDa) important in cell signaling. Cytokines are produced by a broad range of cells, including immune cells like macrophages, B cell, B lymphocytes, T cell, T lymphocytes ...

, which aid the immune system. According to Wright, the production of smegma, which is low in childhood, increases from adolescence until sexual maturity when the function of smegma for lubrication assumes its full value. From middle-age, production starts to decline and in old age virtually no smegma is produced. Jakob Øster reported that the incidence of smegma increased from 1% among 6- to 9-year-olds to 8% among 14- to 17-year-olds (amongst those who did not present with

phimosis Phimosis (from Greek language, Greek φίμωσις ''phimōsis'' 'muzzling') is a condition in which the foreskin of the Human penis, penis cannot stretch to allow it to be pulled back past the Glans penis, glans. A balloon-like swelling under ...

and could be examined).

Clinical significance and hygiene

The production of smegma, which increases during puberty, can only be of limited significance, as males and females learn to practice good genital hygiene. Smegma can cause irritation and inflammation in men, which can increase the risk of

penile cancer Penile cancer, or penile carcinoma, is a cancer that develops in the skin or tissues of the penis. Symptoms may include abnormal growth, an ulcer or sore on the skin of the penis, and bleeding or foul smelling discharge. Risk factors include phimo ...

. In the past some experts used to be concerned smegma itself might cause cancer.

Other animals

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 foetus''. Accumulation of smegma in the

equine Equinae is a subfamily of the family Equidae, known from the Hemingfordian stage of the Early Miocene (16 million years ago) onwards. They originated in North America, before dispersing to every continent except Australia and Antarctica. They are ...

preputial folds and the

urethral fossa A stallion is an adult male horse that has not been gelded ( castrated). Stallions follow the conformation and phenotype of their breed, but within that standard, the presence of hormones such as testosterone may give stallions a thicker, "cre ...

and urethral diverticulum can form large "beans" and promote the carriage of ''

Taylorella equigenitalis Taylorella is a genus comprising Gram-negative, short rod-shaped, chemoorganotrophic bacteria that include species that are the causative agents of contagious equine metritis. The name Taylorella serves as a dedication to C.E.D. Taylor, the scien ...

'', the causative agent of

contagious equine metritis Contagious equine metritis (CEM) is a type of metritis (uterine inflammation) in horses that is caused by a sexually transmitted infection. It is thus an equine venereal disease of the genital tract of horses, brought on by the ''Taylorella equi ...

. Some equine veterinarians have recommended periodic cleaning of male genitals to improve the health of the animal.

References

External links