Bulbourethral gland
A
bulbourethral gland (or
Cowper's gland) is one of two small
exocrine glands present in the reproductive system of human males. They are
homologous to
Bartholin's glands in females. Bulbourethral glands are located behind and lateral to the membranous portion of the
urethra at the base of the penis, between the two layers of the
fascia of the
urogenital diaphragm, and enclosed by the transverse fibers of the
sphincter urethrae membranaceae muscle.
The bulbourethral glands are
compound tubuloalveolar glands, each approximately the size of a pea. 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, opening into a duct which 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 urethra at the base of the penis. The glands appear to gradually diminish in size as age advances.
During
sexual arousal each gland produces a clear, viscous secretion known as
pre-ejaculate or "pre-cum". This fluid helps to lubricate the urethra for sperm to pass through, and to help flush out any residual urine or foreign matter. The pre-ejaculate can contain sperm and is therefore able to cause pregnancy, even if
ejaculation does not occur.
