Testes and Spermatogenesis

By: T-Dot and A-Dawg(Tyrel and Andrew)

..Introduction to the Testes

Belongs to the Male Reproductive System.[plural for testicle]

..Hormones Secreted

The hormones secreted by the Testes is called testosterone and androsterone. The testes regulate these hormones.

..Testosterone

Is a male sex hormone that is produced by the interstitial cells of the testes. The target cells are peritubular-myoid cells and the sertoli cells. The effects of testosterone in adults is maintenance of muscle mass and strength, maintenance of bone density, mental and physical energy and in males the facial hair (extra areas), the adams apple and the deepening of the voice.

..Too much Testosterone?

Excessive testosterone in males can lead to a greater risk of prostate cancer. Some studies have been done to see if testosterone increases anger/aggression/violent behaviors.

..Introduction to Spermatogenesis

Is the process by which spermatogonia divide and differentiate into mature sperm cells. In essence it is the process by which males sperm are made.

..Regulation

The process of Spermatogenesis is regulated by Seminiferous tubules. These tubules fill the testes of a human male and are continuously producing millions of sperm.

..The Process

“The initial proliferation of male germ cells into spermatogonia proceeds by mitosis in the embryo. Primary spermatocytes then under go the first meiotic division produces *4* haploid spermatids for each primary spermacyte, then enters meiosis. In mammals the progency of primary spermacytes remain connected by cytoplasmic bridges after each division.” – See handout Pg. 899.

Animation

..Mitosis The division of the nucleus of a Eukaryotic

cell into two daughter nuclei with identical sets of chromosomes.

The actual cell division itself it referred to as cytokinesis.

..Meiosis Meiosis is a process by which a diploid

eukaryotic cell divides into *4* haploid cells called gametes. Unlike Mitosis which operates in a cycle, Meiosis is a “one-way” process.

Not enough Sperm? This is known for a male as being Infertile.

This doesn’t mean that the man is incapable of producing sperm, it mainly means that there will be a significant decrease of sperm quantity and or a change in movement of the sperm (they don’t work right).

..Bibliography

Biology 12 Nelson Handouts – Pg. 898 to 978 Wikipedia Google

THE END!!