C h a p t e r 4 0
Disorders of the Female Genitourinary System
1019
portion, called the body; and the inferior constricted
part, called the
cervix
1,2
(see Fig. 40-3). The uterus is
supported on both sides by four sets of ligaments: the
broad ligaments
, which run laterally from the body of
the uterus to the pelvic side walls; the
round ligaments
,
which run from the fundus laterally into each labium
majus; the
uterosacral ligaments
, which run from the
uterocervical junction to the sacrum; and the
cardinal
or
transverse cervical
ligaments, which are attached to the
side of the uterus (Fig. 40-4).
The wall of the uterus is composed of three layers: the
perimetrium, the myometrium, and the endometrium.
2
The
perimetrium,
or outer serosal layer, is derived from
the abdominal peritoneum. This outer layer merges
with the peritoneum that covers the broad ligaments.
Anteriorly, the perimetrium is reflected over the blad-
der wall, forming the
vesicouterine pouch
; posteriorly, it
extends to form the
rectouterine pouch
(see Fig. 40-1).
Because of the proximity of the perimetrium to the uri-
nary bladder, a bladder infection often causes uterine
symptoms, particularly during pregnancy.
The
myometrium
, or middle muscle layer of smooth
muscle fibers, forms the major portion of the uterine
wall. It is continuous with the muscle layer of the uterine
tubes and the vagina. The smooth muscle also extends
into the ligaments connected to the uterus. The inner
fibers of the myometrium run in various directions, giv-
ing it an interwoven appearance. Contractions of these
muscle fibers help to expel menstrual flow and the prod-
ucts of conception during miscarriage or childbirth.
The
endometrium
, or inner mucosal layer of the
uterus, is continuous with the epithelial lining of the
uterine tubes and vagina. It is actively involved in the
menstrual cycle, differing in structure with each stage
of the cycle (to be discussed). If conception occurs, the
products of conception are implanted in this layer; if
conception does not occur, the inner surface of this layer
is shed through menstruation.
The round cervix forms the neck of the uterus. The
opening, or os, of the cervix forms a pathway between
the vagina and the uterus. The vaginal opening is called
Fundus
of uterus
Uterotubal
junction
Uterine tube
Uterine cavity
Perimetrium
Myometrium
Endometrium
Internal os
Cervical canal
Fornix of vagina
Vagina
External os
Vaginal orifice
Vestibule
of vagina
Cervix
Supravaginal
part
Vaginal part
Isthmus
Body
Uterine
horn
FIGURE 40-3.
Median section of the vagina and uterus.
(From Moore KL, Agur AMR. Essential Clinical Anatomy. 2nd
ed. Philadelphia, PA: Lippincott Williams &Wilkins; 2002:238.)
Ovarian
ligament
Ovary
Ruptured
ovarian
follicle
Uterosacral
ligament
Broad
ligament
Cardinal
ligament
Round ligament
of uterus
Path of oocyte
Fundus
Frequent site of implantation
Suspensory ligament of ovary
Site of fertilization
Uterine
tube
Fimbriae
Path of sperm
A
B
FIGURE 40-4.
Schematic drawing of female reproductive organs, showing
(A)
suspensory ligament
of the ovary and the broad, uterosacral, and cardinal ligaments on the left, and
(B)
the path of the
oocyte as it moves from the ovary into the fallopian (uterine) tube; the path of sperm is also shown,
as is the usual site of fertilization.
