Page 163 - Clinical Anatomy

ECA2 7/18/06 6:43 PM Page 148

148 The abdomen and pelvis

must always be sought after in this disease). Collections of fluid, malignant
deposits, prolapsed uterine tubes and ovaries or coils of distended bowel
may be felt in the pouch of Douglas.
•◊◊Laterally —the ovary and tube, and the side wall of pelvis. Rarely, a
stone in the ureter may be felt through the lateral fornix. The strength of the
perineal muscles can be assessed by asking the patient to tighten up her
perineum.
•◊◊Apex—the cervix is felt projecting back from the anterior wall of
the vagina. In the normal anteverted uterus the anterior lip of the cervix
presents; in retroversion either the cervical os or the posterior lip are first to
be felt.
Pathological cervical conditions— for example, neoplasm— can be felt,
as can the softening of the cervix in pregnancy and its dilatation during
labour.
Bimanual examination assesses the pelvic size and position of the
uterus, enlargements of ovary or uterine tubes and the presence of other
pelvic masses.
The obstetrician can assess the pelvic size both in the transverse and
anteroposterior diameter. Particularly important is the distance from the
lower border of the symphysis pubis to the sacral promontory, which is
termed the diagonal conjugate. If the pelvis is of normal size, the examiner’s
fingers should fail to reach the promontory of the sacrum. If it is readily pal-
pable, pelvic narrowing is present (see ‘obstetrical pelvic measurements’,
page 128).

Embryology of the Fallopian tubes,
uterus and vagina (Fig. 108)
The paramesonephric (or Müllerian) ducts develop, one on each side, adjacent
to the mesonephric (Wolffian) ducts in the posterior abdominal wall—they are
mesodermal in origin. All these four tubes lie close together caudally, pro-
jecting into the anterior (urogenital) compartment of the cloaca.
One system disappears in the male, the other in the female, each leaving
behind congenital remnants of some interest to the clinician.
In the male, the paramesonephric duct disappears, apart from the
appendix testis and the prostatic utricle. In the female, the mesonephric
system (which in the male develops into the vas deferens and epididymal
ducts) persist as remnants in the broad ligament termed the epöophoron,
paröophoron and ducts of Gärtner.
The paramesonephric ducts in the female form the Fallopian tubes cra-
nially. More caudally, they come together and fuse in the midline (drag-
ging, as they do so, a peritoneal fold from the side wall of the pelvis which
becomes the broad ligament). The median structure so formed differenti-
ates into the epithelium of the uterine body (endometrium), cervical canal
and upper one-third of the vagina, which are first solid and later become
canalized. The rest of the vaginal epithelium develops by canalization of
the solid sinuvaginal node at the back of the urogenital sinus. This accounts
for the differences in lymphatic drainage of the upper and lower vagina