MEN’S INTERNAL SEX AND REPRODUCTIVE ORGANS AND SPERM PRODUCTION: VAS DEFERENS, SEMINAL VESICLES, PROSTATE AND COWPER’S GLANDS

Vas Deferens

Mature sperm are pushed out of each epididymis into a long, thin tube called the vas deferens. The vas deferens connects the epididymis to the seminal vesicle. It moves sperm to the seminal vesicle by contracting and pushing them on their way.

Seminal Vesicles

The seminal vesicles are two small organs that are located beneath bladder. It is here that the sperm are combined with a fluid called seminal fluid. This fluid gives the sperm more room to move and also provides nourishment.

Prostate

The prostate is the next important place on the sperm’s journey. The prostate gland is located below the bladder and is very sensitive. Some men like to have it stimulated during sex play. When sperm, combined with the seminal fluid, reach the prostate, another substance is added to the mixture. The prostate produces a thin, milky fluid that is secreted into the urethra at the time of emission of semen. The substance helps give the sperm an environment in which it can swim easily.

A muscle at the bottom of the prostate gland keeps the sperm out of the urethra until ejaculation begins. Then the sperm move through the urethra in the penis and out of the body.

Cowper’s Glands

While the sperm are waiting, something else is happening to make the voyage easier. Located below the prostate are two Cowper’s glands, which are attached to the urethra. The Cowper’s glands deposit a fluid into the urethra before ejaculation. This fluid acts as a lubricant for the sperm and coats the urethra while flowing out the penis.

If there are sperm in the urethra from a previous ejaculation, they will mix with the Cowper’s fluid. This means that sperm can slide out of the penis before ejaculation. The lubricant is often called pre-ejaculate.

Ejaculation happens when the prostate muscle opens and the prostate gland pumps the seminal fluid into the urethra. It then gets pumped out of the body through the urethral opening. When the final mixture leaves the body, it is called semen.

Some men worry that they may urinate instead of ejaculating. This is impossible. When the penis is erect, a muscle closes off the bladder so no urine can pass through the urethra. It is also not possible for semen to mix into urine during urination because the prostate closes when urine moves into the urethra.

If these muscles are not working correctly, semen can be ejaculated into the bladder instead of out of the body. This is called retrograde ejaculation. This does not happen often. It is most likely to happen to men who have had prostate surgery or who have diabetes or multiple sclerosis. Men who have retrograde ejaculation are still able to have fulfilling sexual relationships and orgasms.