Page 152 - Clinical Anatomy

ECA2 7/18/06 6:43 PM Page 137

The female genital organs 137

from the mons pubis to meet posteriorly in the midline of the perineum.
They are the equivalent of the male scrotum.
The labia minora lie between the labia majora as lips of soft skin which
meet posteriorly in a sharp fold, the fourchette. Anteriorly, they split to
enclose the clitoris, forming an anterior prepuce and posterior frenulum.
The vestibule is the area enclosed by the labia minora and contains the
urethral orifice (which lies immediately behind the clitoris) and the vaginal
orifice.
The vaginal orifice is guarded in the virgin by a thin mucosal fold, the
hymen, which is perforated to allow the egress of the menses, and may have
an annular, semilunar, septate or cribriform appearance. Rarely, it is imper-
forate and menstrual blood distends the vagina (haematocolpos). At first
coitus the hymen tears, usually posteriorly or posterolaterally, and after
childbirth nothing is left of it but a few tags termed carunculae myrtiformes.
Bartholin’s glands (the greater vestibular glands) are a pair of lobulated,
pea-sized, mucus-secreting glands lying deep to the posterior parts of the
labia majora. They are impalpable when healthy but become obvious when
inflamed or distended. Each drains by a duct 1 in long which opens into the
groove between the hymen and the posterior part of the labium minus.
Anteriorly, each gland is overlapped by the bulb of the vestibule—a mass
of cavernous erectile tissue equivalent to the bulbus spongiosum of the
male. This tissue passes forwards, under cover of bulbospongiosus, around
the sides of the vagina to the roots of the clitoris.

Clinical features

At childbirth the introitus may be enlarged by making an incision in the
perineum (episiotomy). This starts at the fourchette and extends mediolater-
ally on the right side for 1.5in (3cm). The skin, vaginal epithelium, subcuta-
neous fat, perineal body and superficial transverse perineal muscle are
incised. After delivery the episiotomy is carefully sutured in layers.

The vagina (Fig. 101)

The vagina surrounds the cervix of the uterus, then passes downwards and
forwards through the pelvic floor to open into the vestibule.
The cervix projects into the anterior part of the vault of the vagina so that
the continuous gutter surrounding the cervix is shallow anteriorly (where
the vaginal wall is 3in (7.5cm) in length) and is deep posteriorly (where the
wall is 4in (10cm) long). This continuous gutter is, for convenience of
description, divided into the anterior, posterior and lateral fornices.

Relations
•◊◊Anteriorly — the base of the bladder and the urethra (which is em-
bedded in the anterior vaginal wall).
•◊◊Posteriorly — from below upwards, the anal canal (separated by the