The
p erin eu m
is the diamond-shaped area between the
thighs and buttocks of both males and females that con-
tains the external genitals and anus.
The female external genitals are called the
vu lva
or
p u d en d u m
(Figure 16.7). The mons pubis (MONZ PÜ-
bis) is an elevation of adipose tissue covered by pubic hair,
which cushions the pubic symphysis. From the mons pubis,
two longitudinal folds of skin, the labia majora (LÀ-be-a
ma-JO-ra), extend down and back. In females, the labia
majora develop from the same embryonic tissue as the
scrotum in males. The labia majora contain adipose tissue
and sebaceous (oil) and sweat glands. Like the mons pubis,
they are covered by pubic hair. Medial to the labia majora
are two folds of skin called the labia minora (mi-NO-ra).
The labia minora do not contain pubic hair or fat and have
few sweat glands; they do, however, contain numerous se-
baceous (oil) glands.
The clitoris (KLIT-o-ris) is a small, cylindrical mass
of erectile tissue and nerves. It is located at the interior
junction of the labia minora. A layer of skin called the
p re-
p uce
is formed at a point where the labia minora unite and
cover the body of the clitoris. Like the penis, the clitoris is
capable of enlargement upon sexual stimulation.
The region between the labia minora is called the ves-
tibule. This region contains the hymen (if present), the
vaginal opening, and the opening of the urethra. On either
side of the vaginal orifice are the
greater vestibular g la n d s,
which produce a small quantity of mucus during sexual
arousal and intercourse that adds to cervical mucus and
provides lubrication.
The mammary glands are located in the breasts and
are also considered part of the female reproductive system.
They are modified sweat glands that develop during pu-
berty and change during pregnancy to produce milk to feed
the baby after birth (Figure 16.8). We will discuss develop-
ment, birth, delivery, and lactation later in the chapter.
The breasts lie over the pectoralis major and serratus
anterior muscles and are attached to them by a layer of
connective tissue. Each breast has one pigmented projec-
tion, the nipple, with a series of closely spaced openings
where milk emerges. The circular pigmented area sur-
rounding the skin is called the areola (a-RE-o-la). This re-
gion contains modified sebaceous (oil) glands.
Internally, each mammary gland consists of 15 to 20
lobes arranged radially and separated by adipose tissue and
strands of connective tissue called suspensory ligaments
of the breast, which support the breast. In each lobe are
smaller lobules, in which milk-secreting glands called alveo-
li are found. When milk is being produced, it passes from the
alveoli into a series of tubules that drain toward the nipple.
At birth, the mammary glands are undeveloped and
appear as slight elevations on the chest. With the onset
C o m p o n e n t s o f t h e v u l v a
F i g u r e 1 6 . 7
Like the penis, the clitoris is capable of erection on sexual stimulation.
Mons pubis
Labia majora (spread) —
Labia minora (spread
exposing vestibule)
The
hymen
is a thin
------
mucous membrane
covering the vaginal
opening. The hymen
usually breaks during the
first sexual intercourse.
Inferior view
Prepuce of clitoris
The clitoris is a small cylindrical
mass of erectile tissue and nerves.
External urethral orifice
Vaginal orifice (dilated)
Anus
478 CHAPTER 16
The Reproductive Systems
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