Understanding the male reproductive system

How much sperm do men have? 

Unlike women who have a finite supply of eggs and release one each month, a man makes sperm continuously in the testes after puberty. 

The male reproductive system has three main functions:

• Produce and transport sperm (male reproductive cells) in protective fluid (semen)
• Discharge sperm within the female reproductive tract during sexual intercourse
• Produce and secrete male sec hormones necessary to maintain the male reproductive system

Male reproductive organs

The male reproductive system is located outside of the body and consists of internal and external organs. Let’s explore these more. 

External organs

Penis

The penis is used in sexual intercourse to transport semen and urine, and has a number of sensitive nerve endings. 

Scrotum

The loose pouch-like sac of skin hanging below the penis, the scrotum contains the testes, nerves and blood vessels. For normal sperm development, the testes must be at a slightly cooler temperature than body temperature. Special muscles in the scrotum allow it to contract and relax, moving the testicles toward or away from the body to control the temperature. 

Testis 

The testicles are oval organs that lie in the scrotum, responsible for making testosterone and generating sperm. 

Internal organs (or accessory organs)

Urethra

This is the tube that carries urine from the bladder to outside of the body. This also ejaculates semen when the man reaches an orgasm. When the penis is erect, the flow of urine is blocked from the urethra which only allows semen to be ejaculated at orgasm. 

Prostate gland

Located below the urinary bladder in front of the rectum, the prostate gland contributes to additional fluid for ejaculation and nourishes the sperm. The urethra runs through the center of the prostate gland. 

Ejaculatory duct

The ejaculatory duct is formed by the vas deferens and the seminal vesicles and empties into the urethra. 

Vas deferens

The vas deferens transports mature sperm to the urethra to prepare for ejaculation. 

Epididymis

This transports and stores sperm cells produced in the testes, and brings sperm to maturity since the sperm that emerge from the testes are immature and incapable of fertilization. When the male is sexually aroused, contractions force the sperm into the vas deferens. 

The male reproductive process

The male reproductive system is dependent on hormones Follicle-stimulating hormone (FHS), Luteinizing hormone (LH) and testosterone. The pituitary gland releases FSH and LH, necessary for sperm production and stimulation of testosterone. 

During sexual intercourse, the sperm leave the testis and travel through the epididymis, finally reaching the vas deferens where the sperm mature. During ejaculation, the sperm move toward the ejaculatory duct, where they mix with fluid from the seminal vesicles and prostate gland. The combination of sperm and fluid is called semen, which allows sperm to travel outside of the body. 

In order for fertilization to occur, a man must have a sufficient number of normal sperm able to travel through the woman’s vagina, to the uterus and then the fallopian tubes to meet an egg.