Male Anatomy

The job of the male reproductive system is to produce sperm and deliver it into the female reproductive tract. Sperm cells hand down genes from generation to generation.

Every cell in the human body, except sperm and egg cells, contain fortysix chromosomes, the equivalent of two full copies of the human genetic code. It is the interaction of the two copies of the genome that produces the distinct characteristics people exhibit. Each sperm (and egg) cell carries only half of the forty-six chromosomes. When a sperm cell fertilizes an egg, the genetic material it contains combines with the egg's genetic material to create an embryo.

Sperm Production

In a normal healthy male, there is a complex process involved in making sperm. This process takes place in the testicles and is driven by the endocrine (hormonal) system. The hormones involved include some of the same hormones that play a role in your menstrual cycle, including luteinizing hormone (LH), follicle stimulating hormone (FSH), and gonadotropin releasing hormone (GnRH). The first two of those are produced in his pituitary gland, while GnRH is released by the male's hypothalamus, a tiny structure in the brain. Through a system of chemical messages from the GnRH, his body releases the FSH and LH, which in turn stimulates cells to begin producing testosterone. The testosterone and FSH facilitate the process of sperm production in the man's testes.

It takes about seventy-two days to create and mature a sperm cell (spermatozoa). Each sperm is made up of three essential parts: the head, the midpiece, and the tail. Sperm require a cooler environment than our body temperature to survive; therefore, they are housed in a man's scrotum, which hangs just outside of his body.

The Scrotum

The scrotum is an external sac located just behind the penis and contains the testicles, the two small organs that produce sperm. One of the scrotum's main functions is to regulate the temperature of the testicles. The sperm cells are very sensitive to changes in temperature, so it is important to keep the temperature as regular as possible. If the man's body becomes too warm, the scrotum will relax and lower the testicles away from the excess body heat. If the testicles are too cool, the scrotum will tense up and pull closer to the body.

The male reproductive system

The Penis

Sperm cells pass from the testicles, where they're made, into the body where they pass through several small glands, including the prostate. These glands secrete fluids that are added to the sperm to create a mixture called semen. This fluid contains special proteins and chemicals that contribute to the survival of the sperm cells while they are in the female reproductive tract. The semen will eventually make its way out of the body as ejaculate. At each ejaculation, be it from sex or masturbation, between 20 and 200 million sperm are released.

Many people think of the penis as the main male organ of reproduction. Its job is to penetrate the female partner and deliver sperm from the scrotum to the inside of her body. The penis is rich in blood vessels and spongy tissue that, when sexually aroused, fill with blood and cause the penis to harden, making penetration possible.

Sperm will build up if a man doesn't ejaculate for a long period of time. Some of the built-up sperm will die away and be reabsorbed in the man's body, and some will be washed away as he urinates. This buildup of sperm isn't harmful to a man in any way, nor will it affect future fertility.

Another branch of the urethra carries urine from the bladder to the outside of the body, through the same opening, or meatus, as the sperm. There is a special valve that prevents urine from exiting the bladder when he is sexually aroused.

  1. Home
  2. Fertility
  3. Understanding Your Body
  4. Male Anatomy
Visit other About.com sites: