The bulbourethral glands or Cowper's glands (named for English anatomist

William Cowper William Cowper ( ; 26 November 1731 – 25 April 1800) was an English poet and Anglican hymnwriter. One of the most popular poets of his time, Cowper changed the direction of 18th-century nature poetry by writing of everyday life and sce ...

) are two small

exocrine Exocrine glands are glands that secrete substances on to an epithelial surface by way of a duct. Examples of exocrine glands include sweat, salivary, mammary, ceruminous, lacrimal, sebaceous, prostate and mucous. Exocrine glands are one of t ...

glands in the reproductive system of many male mammals (of all domesticated animals, they are absent only in dogs). They are homologous to Bartholin's glands in females. The bulbouretheral glands are responsible for producing a pre-ejaculate fluid called Cowper's fluid (known colloquially as ''pre-ejaculate'' or ''pre-cum''), which is secreted during sexual arousal, neutralizing the acidity of the urethra in preparation for the passage of sperm cells.

Location

Bulbourethral glands are located posterior and lateral to the membranous portion of the

urethra The urethra (from Greek οὐρήθρα – ''ourḗthrā'') is a tube that connects the urinary bladder to the urinary meatus for the removal of urine from the body of both females and males. In human females and other primates, the urethra c ...

at the base of the

penis A penis (plural ''penises'' or ''penes'' () is the primary sexual organ that male animals use to inseminate females (or hermaphrodites) during copulation. Such organs occur in many animals, both vertebrate and invertebrate, but males d ...

, between the two layers of the fascia of the

urogenital diaphragm Older texts have asserted the existence of a urogenital diaphragm, also called the triangular ligament, which was described as a layer of the pelvis that separates the deep perineal sac from the upper pelvis, lying between the inferior fascia of ...

, in the deep perineal pouch. They are enclosed by transverse fibers of the sphincter urethrae membranaceae muscle.

Structure

The bulbourethral glands are compound tubulo-alveolar glands, each approximately the size of a pea in humans. In

chimpanzees The chimpanzee (''Pan troglodytes''), also known as simply the chimp, is a species of great ape native to the forest and savannah of tropical Africa. It has four confirmed subspecies and a fifth proposed subspecies. When its close relative th ...

, they are not visible during dissection, but can be found on microscopic examination. In boars, they are up to 18 cm long and 5 cm in diameter. They are composed of several lobules held together by a fibrous covering. Each lobule consists of a number of acini, lined by columnar

epithelial cells Epithelium or epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. It is a thin, continuous, protective layer of compactly packed cells with a little intercell ...

, opening into a duct that joins with the ducts of other lobules to form a single excretory duct. This duct is approximately 2.5 cm long and opens into the bulbar urethra at the base of the penis. The glands gradually diminish in size with advancing age.'' Gray's Anatomy'', 38th ed., p 1861.

Function

The bulbourethral gland contributes up to 4 ml of fluid during sexual arousal. The secretion is a clear fluid rich in mucoproteins that help to lubricate the distal

and neutralize acidic

urine Urine is a liquid by-product of metabolism in humans and in many other animals. Urine flows from the kidneys through the ureters to the urinary bladder. Urination results in urine being excreted from the body through the urethra. Cellular ...

which remains in the urethra. According to one preliminary study, the bulbourethral gland fluid might not contain any sperm, whereas another study showed some men did leak sperm in potentially significant quantities (in a range from low counts up to 50 million sperm per ml) into the pre-ejaculatory fluid, potentially leading to conception from the introduction of pre-ejaculate. However, the sperm source is a residual or pre-ejaculatory leak from the testicles into the

vas deferens The vas deferens or ductus deferens is part of the male reproductive system of many vertebrates. The ducts transport sperm from the epididymis to the ejaculatory ducts in anticipation of ejaculation. The vas deferens is a partially coiled tube ...

, rather than from the bulbourethral gland itself.

Gallery

File:Illu penis.jpg, Structure of the penis File:Gray1136.png, Male pelvic organs seen from right side. File:Gray1156.png, Vertical section of bladder, penis, and urethra. File:Gray543.png , Bulbourethral gland labeled at center left.

References

{{DEFAULTSORT:Bulbourethral Gland Exocrine system Glands Mammal male reproductive system

Location

Structure

Function

Gallery

See also

References