Answer: Testosterone, from the Leydig cells.
- A Testosterone, from the Leydig cells
- B Progesterone, from interstitial cells
- C Relaxin, from interstitial cells
- D Estrogen, from interstitial cells
Correct answer: A. Testosterone, from the Leydig cells
Explanation: Leydig cells of the testes secrete testosterone, which regulates the development of secondary sexual characters and spermatogenesis.
The hypothalamus releases hormones that direct the pituitary, which releases its own trophic hormone to a target gland; that gland's hormone output then feeds back (dashed lines) to suppress both the pituitary and hypothalamus once levels are sufficient - a self-correcting loop running the entire endocrine system.
Concept context
The endocrine glands, hormone classification and mechanism of action, and negative feedback regulation.