Final answer:
The prostate gland is the muscular gland located at the base of the male urethra. It contributes significantly to reproductive health by providing an alkaline fluid that coagulates and later decoagulates semen.
Step-by-step explanation:
The muscular gland at the base of the male urethra is the prostate gland. It is located anterior to the rectum and at the base of the bladder, surrounding the prostatic urethra which is a part of the male urethra that runs within the prostate. The prostate gland is about the size of a walnut and is made up of both muscular and glandular tissues. It plays a crucial role in male reproductive health by excreting an alkaline, milky fluid into the passing seminal fluid, which becomes semen. This secretion from the prostate is essential for coagulating and then decoagulating the semen after ejaculation, aiding in retaining the semen within the female reproductive tract for an adequate duration to allow sperm to capitalize on the fructose from seminal vesicle secretions. When the semen becomes more fluid, sperm can advance further into the female reproductive tract.