It's important to start with a good understanding of how the male reproductive system works. When you have this basic knowledge it will be much easier to understand how and why the process can go awry. The process of producing and emitting sperm is a process called “spermatogenesis.”

Making Sperm

In a normal healthy male, there is a complex process to make sperm. The process of making sperm takes place in the testicles, driven by the endocrine (hormonal) system. The hormones involved include some hormones that are by now familiar to you, including luteinizing hormone (LH), follicle stimulating hormone (FSH), and gonadotropin releasing hormone (GnRH).

Luteinizing hormone (LH) and follicle stimulating hormone (FSH) are produced in his pituitary gland. The pituitary gland is controlled by his hypothalamus, which releases the GnRH. Through a system of chemical messages from the GnRH, his body releases the FSH and the LH, which in turn stimulates cells to begin producing testosterone. The testosterone and follicle stimulating hormone (FSH) facilitate the process of sperm production in the man's testes.

It takes about 72 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; therefore, they are housed in a man's scrotum, which hangs outside of his body.

The scrotum is a sac-like structure located beneath the penis. One of its main functions is to control the temperature of the testicles by raising and lowering itself in relationship to the man's body and whether it is warm or cool.

If the testicles are too warm, the scrotum lowers itself away from his body. If the testicles are too cool, the scrotum will draw itself up closer to the body to warm the testicles. This all helps keep the sperm and testicles at just the right temperature.

Releasing Sperm

At each ejaculation, whether that is from sex or masturbation, about 20 to 200 million sperm are released. If a man does not ejaculate for a long period of time, the sperm will build up. Contrary to popular teenage belief, his testicles will not explode if he does not ejaculate. Some of the built-up sperm will die away and be reabsorbed in the man's body. Some of the sperm will be washed away as he urinates. This buildup of sperm is not harmful to a man in any way, nor will it affect future fertility.

For ejaculation to take place several things must occur. The man must be able to maintain an erection. An erection is caused by arousal, which causes additional blood flow to the penis. The blood vessels in the penis engorge, causing the penis to become harder to the touch. This allows for easier penetration.

When the man reaches orgasm, the sperm travels through the maze of tubing through the vas deferens, the seminal vesicles, and the urethra, where the sperm and semen combination will leave his body. The additional blood in the penis is released back into the rest of the body as the erection is no longer needed and the penis reverts back to its normally flaccid state.

Once ejaculated, sperm swims to reach your egg. The tail of the sperm gives it the mobility it needs for its journey. It will beat itself around causing a forward motion of the sperm. Sperm swims at the rate of 3mm (.12 inches) per hour — this may not sound very fast, but it does the job.

While a woman's ability to produce eggs is limited largely by age, the same cannot be said of the male. Over the course of his life, a man will continue to produce sperm. This is good news for men who wish to conceive later in life.

Normal Male Parameters for Semen