The Anatomy of the Seminal Vesicles

Their main function is to produce a fluid that makes up semen, which is released duringejaculation.

They are about 2 cm4 cm (centimeters) long and 1 cm2 cm in diameter.

They usually extend back and out from the base of theprostategland, a bit like rabbit ears.

seminal vesicles

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The outside of the vesicles are lined by a coat of smooth muscle, which can contract during ejaculation.

Location

The seminal vesicles are located between the bladder fundusand the rectum.

Occasionally, boys are born with abnormalities of the seminal vesicles.

One or both seminal vesicles may be absent (a condition called agenesis).

Men withcystic fibrosissometimes have missing seminal vesicles.

Cystsof the seminal vesicles can be congenital or acquired.

Acquired cysts are often due to an infection, obstruction of the duct, or other sources of inflammation.

Cysts are usually small and on one side, although rarely they may become quite large.

The fluid produced by the seminal vesicles is stored in the vesicles themselves.

For example, people with seminal vesicle cysts at birth are often missing one of their kidneys.

Congenital abnormalities like these may require surgery for correction.

Men with infertility may undergo analysis of their seminal fluid.

Ultrasound and CT are the least expensive and most widely available types of imaging.

They are often first ordered in men with urinary difficulties or pelvic pain.

They can be helpful in detecting signs of infection or inflammation in the seminal vesicles or nearby organs.

MRI produces the most detailed images of the seminal vesicles.

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