prostate gland, a key part of the male reproductive system,
is linked closely with the urinary system. It is a small
gland that secretes much of the liquid portion of semen,
the milky fluid that transports sperm through the penis
The prostate is located just beneath the bladder, where
urine is stored, and in front of the rectum. It encircles,
like a donut, a section of the urethra. The urethra is the
tube that carries urine from the bladder out through the
penis. During ejaculation, semen is secreted by the prostate
through small pores of the urethra's walls.
The prostate is made up of three lobes encased in an outer
covering, or capsule. It is flanked on either side by the
seminal vesicles, a pair of pouch-like glands that contribute
secretions to the semen. Next to the seminal vesicles run
the two vas deferens, tubes that carry sperm from the testicles.
The testicles, in addition to manufacturing sperm, produce
testosterone, a male sex hormone that controls the prostate's
growth and function.