Let us take you back, if only briefly, to the awkward days of your youth squirming in your seat as you learned about human reproduction and the anatomy of the male reproductive system for the first time. Consider this a brief lesson in review.
In contrast to the female whose sex organs site entirely inside the body, the male reproductive organs, also called the genitals, sit both inside and outside his body and include his:
- Duct system—made up of the epididymis and the vas deferens
- Accessory glands, which include the seminal vesicles and prostate gland
The two testicles, also called testes, are oval-shaped and grow to be about 2 inches (5 centimeters) in length and 1 inch (3 centimeters) in diameter. The testicles, which produce and store millions of sperm cells, are also part of the endocrine system given that they also have responsibility for producing hormones, such as testosterone.
Near the testicles are the epididymis—an organ that stores sperm while they mature—and the vas deferens—a part of the duct system that transports semen (a fluid that typically contains sperm) from the epididymis to the penis.
The epididymis and the testicles are located outside the male body in the scrotum—a pouch of skin that holds the testicles and regulates their temperature. (A cooler temperature is needed to produce sperm; you should avoid overheating if you are trying to conceive.)
The accessory glands, which include the seminal vesicles and the prostate gland, surround the ejaculatory ducts (the canal through which a man ejaculates semen) at the base of the urethra (a channel that carries semen and urine outside the body by way of the penis). The seminal vesicles add nutrient fluid to semen during ejaculation. The prostate gland secretes an alkaline fluid that makes up part of the semen and enhances the movement (motility) and fertility of sperm.
The penis is where semen and urine exit the body through the urethra. The inside of the penis is made of a spongy tissue that can expand and contract.
THE ENDOCRINE SYSTEM
The endocrine system refers to the collection of glands that secrete hormones directly into the circulatory system to be carried towards distant target organs. The major endocrine glands include the pineal gland, pituitary gland, pancreas, ovaries (in females), testes (in males), thyroid gland, parathyroid gland, hypothalamus, and adrenal glands.
As part of the endocrine system, there are four main hormones that are responsible for sperm production:
Gonadotropin (GnRH): Gonadotropin, which is released from the hypothalamus, plays a vital role in human sperm production as it coordinates the release of the other hormones that are also involved in the production of sperm, specifically luteinizing hormone (LH) and follicle-stimulating hormone (FSH) that are released from the pituitary gland.
Follicle-stimulating hormone (FSH): Produced in the pituitary gland, this hormone plays a vital role in the production of sperm and stimulates the germ cells in both males and females to mature.
Luteinizing hormone (LH): In men, LH works together with FSH to produce sperm.
Testosterone: As a male makes his way through puberty, testosterone plays a major role and his testicles start producing more and more of this important hormone. Testosterone is another hormone that stimulates the production of sperm. As well, testosterone is very important for the development of the male reproduction tissues like prostate and testes.