Infertility patients starting treatment often feel they are getting a crash course in their reproductive anatomies. It's important for them to have a good understanding of how their reproductive systems work and what might be the causes of their fertility challenges when problems arise.
Men (and women) will be familiar with their scrotum, testes and penis, but may not know the functions of the other organs that help them create, transport and release sperm. The organs also move sperm into the female reproductive tract and secrete male sex hormones.
An overview of male reproductive organs
Scrotum -- the scrotum, a loose sac-like pouch situated on both sides of the penis, is the temperature control center for the testes and plays a major role in keeping it cool and below body temperature. It contains the testes (testicles), nerves and blood vessels.
Testicles -- contained in the scrotum, the testicles (testes) produce sperm and testosterone within the 300 tubules densely packed inside these organs.
In the developing male fetus, the testes form in the abdomen and descend into the scrotum. In two to four percent of infant boys, this does not happen, and they are born with undescended testicles. Also called cryptorchidism, this condition can be surgically corrected.
Epididymis -- the epididymis has both storage and transport functions. It is a long, coiled tube on the back of each testis that looks like a curved structure from behind. Its head stores sperm in preparation for maturation; the body is where sperm matures, which takes one week; and the tail connects to the vas deferens.
Vas deferens -- the vas deferens is a coiled tube that transports sperm from the epididymis in the testes to the urethra through a process called peristalsis, which propels sperm to move forward. Along the way, three glands secrete the fluids that comprise semen. They are the seminal vesicles, prostate gland, and the bulbourethral glands.
A vasectomy is a male form of birth control where a surgeon cuts the vas deferens tubes to prevent sperm transmission.
Seminal vesicles -- the two seminal vesicles or glands supply part of the fluid that combined with sperm forms semen. The fluid helps the sperm move forward as well as nourish it. It also gives semen its sticky, clotting property.
These tubular glands are located behind the bladder, above the prostate gland and in front of the rectum in the pelvic region.
Ejaculatory ducts -- these ducts function in the ejaculation process, which has two stages: emission and expulsion. They form from the union of the vas deferens with the seminal vesicle duct.
The amount of semen created depends on the length of time of arousal occurs before ejaculation.
Prostate gland -- the prostate gland, situated around the urethra and beneath the bladder, produces prostate fluid, one of the prime components of semen. As semen starts to thicken, Prostate Specfici Antigen (PSA) helps to liquefy it.
Cowper's glands -- also known as the bulbourethral glands, they serve a protective function by secreting an alkaline mucous substance known as a pre-ejaculate during sexual stimulation. The pre-ejaculate protects sperm from damage as it passes through the urethra during ejaculation.
Urethra -- carrying urine from the bladder is the primary function of the urethra. It also ejaculates semen when the man reaches orgasm.
Penis -- the penis is the male's primary organ for both sexual reproduction and urination. It has several parts, including the root, the body, the shaft and the foreskin.
Semen and sperm -- semen is the fluid ejaculated by the penis when a man orgasms. Semen contain sperm, the male genetic material. It is more formally called spermatoza, its scientific name.
Sperm combines with fluids secreted by the seminal vesicles, prostate gland, and the bulbourethral gland to form semen. Sperm combines with fluids secreted by the seminal vesicles, prostate gland, and the bulbourethral gland to form semen. Sperm are sensitive to heat or cold and quickly die if they are not deposited into the vagina.
As this overview demonstrates, the male reproductive system is complex, and its organs and glands need to work together seamlessly to create a continuous supply of sperm for reproduction.