Seminal Vesicles: Meaning, Function, Semen, and Fertility

Their fluid helps:

• provide energy for sperm;
• support sperm movement;
• protect sperm in the reproductive tract;
• form much of the volume of semen;
• help semen function after ejaculation.

A simple pathway is:

• sperm are produced in the testicles;
• they mature in the epididymis;
• the vas deferens carries them;
• seminal-vesicle fluid is added;
• prostate fluid is added;
• semen leaves through the urethra.

Simple examples include:

• The seminal vesicles produce fluid found in semen.
• They are located behind the bladder.
• Each seminal vesicle connects with a vas deferens.
• Seminal vesicles do not produce sperm.
• Their secretions help support sperm after ejaculation.

Common structures include:

the seminal vesicles

• The seminal vesicles contribute fluid to semen.
• The doctor examined the seminal vesicles with imaging.

a seminal vesicle

• Each seminal vesicle has a folded internal structure.
• A cyst may develop in one seminal vesicle.

seminal-vesicle + noun

• seminal-vesicle fluid;
• seminal-vesicle secretion;
• seminal-vesicle disorder;
• seminal-vesicle cyst.

Common collocations include:

• paired seminal vesicles;
• seminal-vesicle secretions;
• inflammation of the seminal vesicles;
• obstruction of the seminal vesicles;
• seminal fluid production;
• ejaculatory function.

• behind the urinary bladder;
• in front of the rectum;
• above and behind the prostate;
• near the ends of the vasa deferentia.

Each gland is an elongated, tightly folded tube. This folded shape allows a relatively large secretory surface to fit within a small space.

The duct of each seminal vesicle joins the corresponding vas deferens. Together, they form an ejaculatory duct, which passes through the prostate and opens into the urethra.

These may include:

• fructose, which provides energy that sperm can use;
• prostaglandins, which may influence movement within the reproductive tract;
• proteins involved in temporary semen coagulation;
• minerals and other supportive substances;
• alkaline components that help create a favorable environment for sperm.

Their secretion forms a large portion of semen, while sperm themselves make up only a small part of total semen volume.

The main contributors include:

• the seminal vesicles;
• the prostate;
• the testicles and epididymides;
• the bulbourethral glands.

The seminal vesicles do not produce sperm. Instead, their fluid combines with sperm as ejaculation begins.

This distinction is important:

• sperm are reproductive cells;
• seminal fluid is fluid produced by reproductive glands;
• semen is the complete mixture released during ejaculation.

These contractions:

• move sperm through the vas deferens;
• release fluid from the seminal vesicles;
• move the mixture into the ejaculatory ducts;
• help propel semen into the urethra;
• support its release from the penis.

The seminal vesicles contribute to semen production, but they do not directly cause erection, sexual desire, or orgasm.

Those functions involve the nervous system, blood flow, hormones, muscles, and psychological factors.

Problems affecting these glands may alter:

• semen volume;
• sperm transport;
• semen consistency;
• fructose levels;
• ejaculatory function;
• fertility.

Low semen volume does not automatically mean that the seminal vesicles are diseased. It may have many possible causes, including incomplete collection, hormonal conditions, obstruction, recent ejaculation, or retrograde ejaculation.

A fertility evaluation may include semen analysis, physical examination, imaging, and hormone testing.

The seminal vesicles continue producing fluid after a vasectomy. The prostate and other reproductive glands also continue contributing secretions.

As a result:

• ejaculation usually continues;
• semen is still produced;
• semen volume changes very little for most people;
• sexual desire and erection are not directly reduced;
• the semen should eventually contain no sperm.

Follow-up semen testing is necessary because a vasectomy is not immediately effective.

• inflammation or infection;
• cysts;
• blockage of a duct;
• stones or calcification;
• congenital abnormalities;
• tumors;
• involvement from nearby prostate disease.

Possible symptoms may include:

• painful ejaculation;
• pelvic discomfort;
• blood in semen;
• reduced semen volume;
• urinary symptoms;
• infertility.

These symptoms can have many causes and do not necessarily indicate a seminal-vesicle disorder.

Persistent or concerning symptoms should be evaluated by a qualified healthcare professional.

It may result from inflammation, infection, medical procedures, irritation, or conditions involving the prostate, seminal vesicles, urethra, or other reproductive structures.

A single episode is often not serious, especially in younger adults, but repeated bleeding, pain, fever, urinary symptoms, or other changes should be medically assessed.

The source cannot usually be identified by appearance alone.

Seminal vesicles produce sperm.
Sperm are produced in the testicles.

Seminal vesicles contain fully formed semen.
Their secretions combine with sperm and other fluids during ejaculation to form semen.

Removing sperm from semen stops ejaculation.
After vasectomy, the glands still produce fluid, so ejaculation usually continues.

Seminal vesicles control erections.
They contribute to semen production but do not directly create erections.

1. The seminal vesicles are paired glands located behind the bladder.
2. The seminal vesicles produce much of the fluid found in semen.
3. Each seminal vesicle connects with a vas deferens.
4. The seminal vesicles do not produce or store sperm.
5. Fructose in seminal-vesicle fluid helps provide energy for sperm.
6. Blockage of the seminal vesicles may affect semen volume or fertility.
7. The seminal vesicles continue producing fluid after a vasectomy.
8. Painful ejaculation may sometimes involve the prostate or seminal vesicles.

Although they contribute greatly to seminal fluid, they do not control sexual attraction, erection, orgasm, or gender identity. Their main role is reproductive and secretory.

Understanding the seminal vesicles helps explain the difference between sperm and semen, how ejaculation works, why semen remains after vasectomy, and how certain reproductive-health conditions may affect fertility or sexual function.