This organ, large until adolescence, is important for the development of the immune system. The hormone produced by this gland is thymosin . The hormone secreted by this gland is melatonin . The production of this hormone is greatest in the dark. Two are seen here in perfect cross section.
Spermatogenesis occurs in the seminiferous tubule resulting in the production of sperm.
The pituitary hormones FSH and LH are essential for proper functioning of this organ. This page was last updated in August, 1997. All micrographs are the property of Sherri Wick. Students of Biology 2740 and 2840 are welcome to use this page in the study and review of lecture and lab materials in the Human Physiolgoy and Anatomy courses.