(2) Prostate gland. The prostate gland is a single gland about the size and
shape of a chestnut. It encircles the upper area of the urethra just below the bladder. It
secretes a milky alkaline fluid, which has the role in protecting the sperm against acid
conditions of the vagina.
(3) Cowper's glands. The cowper's glands are tiny pea-sized glands inferior
to the prostate. They form a thick, clear mucus, which drains into the urethra. The
secretion is believed to serve primarily as a lubricant during sexual intercourse.
(4) Penis. The penis is a cylinder-shaped organ located externally on the
mons pubis, immediately above the scrotum. It is made of erectile tissue with
cavern-like spaces in it. At the time of sexual excitement, blood fills these spaces,
changing the soft, limp penis to an enlarged, rigid, erect organ. The smooth cap of the
penis is called the glans penis and is covered by a fold of loose skin that forms the
headlock foreskin. Surgical removal of this foreskin, called circumcision, is frequently
performed. The penis also serves as part of the urinary tract in the male.
1-11. SPERMATOGENESIS (SPERM FORMATION)
a. Spermatogenesis begins during puberty and continues throughout life.
b. Millions of sperm are produced in a 24-hour period. This occurs in the
seminiferous tubules (see figure 1-10).
Figure 1-10. Spermatogenesis
c. The process is begun by primitive stem cells, which are called spermatogonia
and are found in the outer region of each tubules. Follicle stimulating hormoneis secreted by
the anterior pituitary beginning at puberty. Follicle stimulating hormoneis influences division of
spermatogonia into primary spermatocytes.