Module 3 Lesson 1 - 5

Lesson Summary

In Lesson 1, you investigated the following focusing questions:

• What are the main structures and functions of the male reproductive system?
• How do these structures support continuity of the human species?
• What is the functional unit of the male reproductive system?

The male reproductive system is designed to produce and release large numbers of sperm. The gametes (sperm) are produced in the gonads (testes), specifically within the seminiferous tubules where the temperature for proper sperm development is controlled by the scrotum. There the developing sperm are supported by the Sertoli cells and are transferred to the epididymis to be matured and stored.

During ejaculation, the vas deferens helps transfer the sperm from the testes to the urethra, picking up the semen or seminal fluids on the way. The seminal fluids help the sperm by providing sugar for energy, alkalinity to neutralize urine and vaginal acids, and a medium for motility. Semen leaves the male body through the penis. The male reproductive system and sperm structure allow for sperm to be deposited into the female and to move through the female reproductive system.

Human reproductive systems are designed uniquely to develop properly functioning gametes, thereby ensuring continuation of the human species. In the male reproductive system, the male gonads (one testis; two testes) produce the functional gametes (the sperm) in the seminiferous tubules. The sperm matures in the epididymis. The Sertoli cells give both structural and secretory support to the developing sperm. Structural support is provided by protecting the developing sperm from the body's immune system, and secretory support is provided by secreting the hormone inhibin. The interstitial cells, located in the seminiferous tubules, support sperm production indirectly by secreting the hormone testosterone. Then, testosterone stimulates the process of spermatogenesis to develop the sperm.