c. Seminal Vesicles. Lying alongside each ductus deferense as it crosses the
back of the bladder is a tubular structure called the seminal vesicle. The seminal
vesicle produces a fluid that becomes part of the ejaculate (see below).
d. Ejaculatory Duct. Each ductus deferens and its corresponding seminal
vesicle converge to form a short tube called the ejaculatory duct. The ejaculatory duct
opens into the urethra within the prostate gland (see below). The ejaculatory duct
carries both spermatozoa and seminal vesicle fluid.
e. Prostate Gland. As the urethra leaves the urinary bladder, a chestnut-size
gland called the prostate gland surrounds its first inch. The prostate gland provides an
additional fluid to be added to the spermatozoa and seminal vesicle fluid.
f. Penis. As the urethra leaves the abdomen, it passes through the penis, the
male organ of copulation.
(1) Surrounding the urethra is a central cylinder of erectile tissue called the
corpus spongiosum. This cylinder is bulb-shaped at each end. The posterior end is
attached to the base of the pelvis. The sensitive anterior end is known as the glans.
CORPUS SPONGIOSUM = spongy body
(2) Overlying the corpus spongiosum is a pair of cylinders of erectile tissue
called the corpora cavernosa. These two cylinders are separate in their proximal fourth
and joined in their distal three-fourths. They are attached to the pubic bones. Together,
the corpus spongiosum and the corpora cavernosa combine to form the shaft of the
penis.
CORPUS CAVERNOSUM = cavernous body
(3) The prepuce, or foreskin, is a covering of skin for the glans. It may be
removed in a surgical procedure called circumcision.
6-20.
SECONDARY SEXUAL CHARACTERISTICS
The secondary sexual characteristics of male include growth of facial pubic, and
chest hair, growth of the larynx to deepen the voice, and deposition of protein to
increase muscularity and general body size.
MD0806
6-15