Concentrations of which hormone stimulate the hypothalamus to increase or decrease hormones that stimulate sperm production in the testes?

• A. Follicle-stimulating hormone (FSH)
• B. Luteinizing hormone (LH)
• C. Gonadotropin-releasing hormone (GnRH)
• D. Progesterone
• E. Testosterone

Answer: (E)

Verified step by step guidance

1. Understand the role of the hypothalamus in regulating hormone levels. The hypothalamus releases hormones that control the pituitary gland, which in turn regulates other glands in the body, including the testes.
2. Identify the hormones involved in the regulation of sperm production. The key hormones are Gonadotropin-releasing hormone (GnRH), Follicle-stimulating hormone (FSH), and Luteinizing hormone (LH).
3. Recognize that testosterone is a crucial hormone produced by the testes that provides feedback to the hypothalamus and pituitary gland. High levels of testosterone can inhibit the release of GnRH from the hypothalamus.
4. Understand the feedback mechanism: When testosterone levels are high, the hypothalamus reduces the secretion of GnRH, which in turn decreases the release of FSH and LH from the pituitary gland, leading to reduced stimulation of the testes.
5. Conclude that testosterone is the hormone that provides feedback to the hypothalamus to regulate the production of hormones that stimulate sperm production in the testes.