Semen also contains liquids that combine to form seminal plasma , which helps keep the sperm cells viable. In the sexually mature human male, sperm cells are produced by the testes singular, testis ; they constitute only about 2 to 5 percent of the total semen volume. As sperm travel through the male reproductive tract, they are bathed in fluids produced and secreted by the various tubules and glands of the reproductive system. After emerging from the testes, sperm are stored in the epididymis , in which secretions of potassium, sodium, and glycerylphosphorylcholine an energy source for sperm are contributed to the sperm cells. Sperm mature in the epididymis. They then pass through a long tube, called the ductus deferens , or vas deferens, to another storage area, the ampulla.
How Is Sperm Produced?
Unlike a woman who will have around mature eggs throughout a lifetime, which can be released from the follicles in the ovaries and potentially be fertilized, a healthy man will produce billions of sperm in his entire lifetime. All the sperm production and maturation take place in the lumen of the seminiferous tubules of the testis as shown in figure 1. Within the walls of these tubules the sperm cells are produced and matures. Also, in the tubes, there are many different cells of which the most important is the Sertoli cells. These cells function to support and nourish the immature sperm cells by giving them nutrients and blood products.
13.59: Human Sperm
Spermatogenesis , the origin and development of the sperm cells within the male reproductive organs, the testes. The testes are composed of numerous thin tightly coiled tubules known as the seminiferous tubules; the sperm cells are produced within the walls of the tubules. Within the walls of the tubules, also, are many randomly scattered cells, called Sertoli cells , that function to support and nourish the immature sperm cells by giving them nutrients and blood products. As the young germ cells grow, the Sertoli cells help to transport them from the outer surface of the seminiferous tubule to the central channel of the tubule.
Unlike the female genitalia , the male reproductive organs are on both the interior and the exterior of the pelvic cavity. They include:. Sperm production occurs in the testicles. Upon reaching puberty , a man will produce millions of sperm cells every day, each measuring about 0. There is a system of tiny tubes in the testicles.