What hormone is secreted by the testes?

The secretion of testosterone by the testes is a key aspect of male reproductive physiology. Testosterone is the primary male sex hormone and is crucial for the development of male characteristics during puberty, including increased muscle mass, deepening of the voice, and the growth of body and facial hair. Additionally, it plays a significant role in regulating libido, sperm production, and overall reproductive health. The testes are the main organs responsible for its production, making testosterone essential for male fertility and overall male health.

In contrast, estrogen is primarily produced by the ovaries, although males also produce small amounts. Oxytocin, often linked to childbirth and bonding, is produced in the hypothalamus and released by the posterior pituitary gland. Melatonin is secreted by the pineal gland and regulates sleep-wake cycles, unrelated to the functions of the testes. Each of these hormones serves different functions and originates from different glands in the body, further distinguishing testosterone as the correct answer in the context of hormone secretion by the testes.