The bulbourethral glands are a pair of small, round glands that sit next to each other inside the base of thepenis. When the penis is aroused, the bulbourethral glands produce amucussecretion that adds lubricating factors to the ejaculate. They’re also known as Cowper’s glands.
Anatomy
Location
Structure
Yellow and about the size and shape of a pea, the bulbourethral glands measure around 0.4 inches in diameter. They’re made up of a network of small ducts (tubes) and sac-like structures called alveoli. Ducts from the bulbourethral glands empty into the urethra.
What Is the Urethra?Theurethrais a duct that carries urine from the bladder to where it’s expelled from the body. In male anatomy, it also is the conduit through which ejaculate (semen) exits the body.
What Is the Urethra?
Theurethrais a duct that carries urine from the bladder to where it’s expelled from the body. In male anatomy, it also is the conduit through which ejaculate (semen) exits the body.
These glands get their blood supply from thearteryof the bulb of the penis, which branches off of the internal pudendal artery, and the bulbourethral artery, which is part of the penile artery. Their nerve supply comes from sympathetic fibers of the hypogastric nerve.
Along with the prostate gland andseminal vesicles, the bulbourethral glands secrete components of semen.
Anatomical Variations
While anatomical features can be largely the same from one person to the next, differences do exist. The bulbourethral glands have a few known anatomical variations.
Some people have extra bulbourethral glands farther up inside the penis. These glands secrete a fluid that’s similar to that of the primary bulbourethral glands.
In rare cases, a male embryo doesn’t develop one or both of these glands. When there’s a gland only on one side, the abnormality is often associated with a similar lack of development of thekidneys.
When both glands fail to develop, it’s sometimes due to agenetic mutation. It may also be associated with a missingvas deferens(the duct that carries sperm from thetesticlesto the urethra), which means the ejaculate doesn’t contain sperm (a condition called azoospermia).The only symptom of this abnormality is infertility.
Function
When the sperm cells leave the testicles and move up through the vas deferens, Cowper’s fluid, prostatic fluid, and fluids from other glands are added to create semen. Cowper’s fluid generally accounts for less than 1% of the total ejaculate.
The bulbourethral glands typically get smaller as you age.
Associated Conditions
Several conditions are commonly associated with the bulbourethral glands, including:
Syringocele
This condition involves acyst(fluid-filled growth) in the duct that leads to the urethra. Also called Cowper’s duct cyst, syringocele is suspected of being congenital (present at birth). It’s somewhat common in children and rarely diagnosed in adults. However, it may be that it’s not actually rare in adults, but is instead an underrecognized problem.
The presence of the cyst leads to a change in pressure that causes the duct to dilate (expand). While most cysts are too small to impair the glands’ ability to excrete fluid or interfere with the urethra, larger ones that do form obstructions are possible. Depending on their location and size, they may be asymptomatic or painful.
Syringocele is typically diagnosed in babies and children who have:
The gold standard for diagnosis is urethrography, which is a type ofradiologyexam usingcontrast dye.Ultrasound,endoscopy, andmagnetic resonance imaging(MRI) can be useful diagnostically, as well.
In most cases of syringocele, the cyst goes away on its own. When treatment is necessary, removal of the cyst is typically accomplished with endoscopic procedures such as cold knife or laser.
Cowperitis
The infection can be acute (short-term) or chronic (long-lasting). Chronic cases are often a complication of syringocele, in which case the cyst may need to be removed for the infection to clear up.
Stones
Calcium stones, similar tokidney stones, can form in the bulbourethral glands, especially in older adults, and lead to blockage and infection. In rare cases, they may causeabscesses.
If the stones don’t cause symptoms, they can generally be left alone. In symptomatic cases, though, treatment generally involves surgical removal of the gland itself. Bulbourethral gland stones are most often diagnosed via pelvic ultrasound.
Cancer
A type ofcancerthat affects the glands, calledadenocarcinoma, can affect the bulbourethral glands and make them irregularly shaped. However, this is very rare.
Typically, cancerous growths will cause narrowing of the urethra and they may or may not involve bloody discharge. Other symptoms may include pelvic pain and rectal discomfort.
Suspected adenocarcinoma of the gland can be confirmed with abiopsy. Treatments generally includeradiationand surgery, butchemotherapymay be useful in some cases.
Summary
The bulbourethral glands are small glands that lubricate the urethra and tip of the penis. They also contribute fluids to semen. Problems within the glands are extremely rare.
10 Sources
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