Male Reproductive System

The components of the male reproductive system consist of the testicles, epididymis and vas deferens.

The testicles (also called testes) are located inside the scrotum (the loose sac of skin that hangs behind the penis) and are two oval organs about the size of large olives. The testicles make the male hormones including testosterone and produce sperm. Disorders of the testes can lead to serious complications, including hormonal imbalances, sexual dysfunction and infertility.

The epididymis is a long, narrow tube, which is coiled and contained beneath a fibrous sheath. It would be approximately nineteen feet in length if it was laid out in a straight line. The epididymis sits on the back of the testes and is divided into head, body and tail regions. Sperm undergo their final development and maturation in the epididymis then they are stored ready for ejaculation. The sperm proceed into the vas deferens, also known as the spermatic cord.

The vas deferens is a narrow, muscular tube that connects the testicles to the urethra. During ejaculation, the sperm flows out of the testicles, through the vas deferens, and into the tube (urethra) that leads outside the body through the penis. The prostate gland, as well as other glands, adds fluid to the sperm along the way.

This is how the male reproductive system plays a role in conception.

The production of sperm is a very complicated process that begins in the testicles. It is controlled by several hormones and these hormones are regulated by the hypothalamus and the pituitary gland located in the brain. Sperm production begins at puberty and lasts until death, given the male remains in good health.

The hypothalamus regulates the hormonal activity of the pituitary gland by secreting gonadotropin-releasing hormone (GnRH). This hormone controls the production of the gonadotropins, follicle-stimulating hormone (FSH) and luteinizing hormone (LH), from the pituitary. LH triggers the production of testosterone which is needed for sperm production. FSH also triggers hormones that help with sperm production.

Sperm production takes about 72 days from beginning to end. Sperm spend their first 50 days in the testicles and the last 22 to 24 days in the epididymis. It is in the epididymis that sperm mature and gain motility (the ability to swim). During sexual activity, motile sperm are ejaculated into the female reproductive tract and begin their journey through the cervix and uterus to the fallopian tubes, where fertilization takes place. There are many pockets, folds or ‘wrong turns’ along the way that can prevent many of the sperm from reaching their final destination. Therefore a lot of sperm are needed for the fertilization process.

More than 15% of couples experience difficulty in conceiving a child after attempting for one year. The male factor plays a role in almost half of the infertility cases.

Causes of male infertility are physical abnormalities of the male reproductive tract, such as epididymal or vas obstruction or impaired sperm production, and sperm abnormalities. However, in most cases of male infertility the cause is unknown.

To determine male fertility we carry out a semen analysis where we test the number, activity and shape of the sperm.