Vas Deferens, Seminal Vesicles, Prostate Gland, Cowper’s Glands, and Semen

The vas deferens is a sperm carrying duct tubes that begins at the testicles and end at the urethra. During ejaculation sperm that are stored in the epididymis move up along the duct tubes into the ejaculatory duct and expelled from the body. The vas deferens tubes are cut or block in the process called male sterilization which prevent sperm from being ejaculated and is the permanent method of birth control for men.

Seminal Vesicles

The seminal vesicles are small glands that produce alkaline fluid which make up large portion of seminal fluid released during ejaculation. The vas deferens move sperm from epididymis into ejaculatory duct and combine with seminal fluid empty from seminal vesicles into ejaculatory duct. The alkaline fluid protects sperm from acidic environment and allowed sperm to survive longer in the vagina.

Prostate Gland

The prostate gland is located underneath the bladder and is made up of muscle fibers and glandular tissues. The prostate gland is about the size and shape of a walnut and produces about 80% of the seminal fluid released during ejaculation. The prostate gland control the flow of urine by closing the urinary opening to the bladder preventing urine from passing through during ejaculation and only passes semen out from the body.

Cowper’s Glands

The cowper’s glands are about the size of a pea located underneath the prostate gland. The cowper’s glands are located one on each side of the urethra that secrete small amount of fluid during sexual arousal. The fluid usually appears as droplets at the tip of the penis and varies among men. Some men produce droplets after sexual arousal, some produce droplets immediately after achieving erection, and some never produce droplets after achieving arousal or erection.

Semen

Semen contains sperm and seminal fluid produced by seminal vesicles, prostate gland, and cowper’s glands. In a single ejaculation semen contain between 200 and 500 million sperm. Semen is made up of citric acids, water, enzymes, fructose, proteins, potassium, prostaglandins, and variety of other substances. Semen is not harmful when swallow during oral sex, but HIV infected semen can transmit the virus through open sores or bleeding gums in the mouth.

Ejaculatory Duct

The ejaculatory duct passes through prostate gland and opens into the urethra that passes semen out of a man’s body.

Urethral Opening

The urethra is the tube connecting the bladder and ejaculatory duct to the urinary opening that passes urine and semen out of a man’s body.

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