Sperm Cells

Sexual FAQs - Sperm Cell or Spermatozoa

The mature sperm cell (spermatozoa) is 0.05mm long. It consists of a head, body and tail. The head is covered by the ac cap and contains a nucleus of dense genetic material from the 23 chromosomes. It is attached from the neck to the body containing mitochondria that supply the energy for the sperm's activity. The tail is made of protein fibers that contract on alternative sides, giving a characteristic wavelike movement that drives the sperm through the seminal fluid, which also supplies additional energy.

Some sperm have two heads or two tails. If the testes are too warm, they may die, or spermatogenesis may not occur.

Sperm swim at a rate of about 3mm (0.12 inches) per minute. That’s an average; it’s different for every guy. Some sperm cells are "better" swimmers than others. Why? They need to wave their tails more than 1,000 times just to swim 1.25cm or 1/2 inch. Why some are better than others is still a mystery to many fertility specialists.

Sperm cells are made in the testes, where it takes about 72 days for one sperm to grow. Sperm production requires a temperature 3 to 5 degrees below body temperature. The scrotum has a built-in thermostat, which keeps the sperm at the correct temperature while they’re being stored. If it becomes too cool on the outside, the scrotum will bring the testicles closer to the body for warmth (as you probably know from jumping into a cold pool of water or ocean). That’s why the testes hang away from the body: so sperm can develop at the temperature they need. (95 to 97 degrees F or 35 to 36 degrees C).

Semen contains small amounts of more than 30 elements, including fructose, ascorbic acid, cholesterol, creatine, citric acid, lactic acid, nitrogen, vitamin B12, and various salts and enzymes.

Let’s go back to the inside of the head of the sperm. All normal cells have 46 chromosomes, but sperm have half that number, or 23. If and when the sperm joins ups with the female’s egg (ovum), which also has 23 chromosomes, together they add up to 46 chromosomes. The middle section controls the sperms activities. The sperm (or spermatozoa--which are the little swimming creatures) make up only about 5 percent of what a man ejaculates each time he ejaculates. This represents about 100 to 400 million of them! Therefore, they are extremely tiny; in fact, a single sperm is the smallest cell in the body.

The rest of what a man ejaculates, which measures about 1 tsp. (5 ml), is made up of water, sugar, protein, vitamin C, zinc and prostaglandins. Semen or seminal fluid is the mixture of sperm and the secretions of the seminal vesicles, prostate gland and bulbourethral glands. Over the course of a guy’s life, he’ll produce more than 12 trillion sperm.