North American Registry of Midwives (NARM) Practice Exam 2025 – The All-in-One Resource to Master Your Midwifery Certification!

Leydig cells, also known as interstitial cells, are located in the testes and play a crucial role in male reproductive health. The primary function of Leydig cells is to synthesize and secrete testosterone, which is the main male sex hormone. Testosterone is pivotal for the development of male secondary sexual characteristics, including facial hair, deeper voice, and increased muscle mass. It also plays a significant role in regulating libido and supporting the production of sperm.

The other hormones listed have different origins and functions within the body. Estrogen, while present in small amounts in males, is primarily produced in the ovaries and is essential for female reproductive functions. Progesterone is mainly associated with female reproductive health, mainly produced in the ovaries and placenta, and is critical for maintaining pregnancy. Prolactin, produced in the pituitary gland, has a primary role in lactation and is not produced by the Leydig cells. Therefore, testosterone is correctly identified as the hormone synthesized and released by Leydig's cells in males.