Introduction
This chapter aims to summarize the important aspects of
the anatomy of the abdomen and the pelvis, which should
be known to the Obstetric or Gynaecological specialist.
Many of the investigations and treatments we order on a
daily basis require good anatomical knowledge in order
to be properly understood.
Surface anatomy
The anterior abdominalwal lcan be divided into four
quadrants by lines passing horizontally and vertically
through the umbilicus (Fig. 1.1). In the upper abdomen
is the epigastrium, which is the area just inferior to the
xiphisternum, and in the lower abdomen lie the right and
left iliac fossae and the hypogastrium.
The cutaneous nerve supply of the anterior abdominal
wall arises from the anterior rami of the lower thoracic
and lumbar vertebrae. The dermatomes of significant
structures on the anterior abdominalwal lar e:
T7 xiphisternum
T10 umbilicus
L1 symphysis pubis
The blood supply is via the superior epigastric (branch
of the internalthoracic artery) and the inferior epigastric
(branch of the external iliac artery) vessels. During
laparoscopy, the inferior epigastric vessels can be seen
between the peritoneum and rectus muscle on the anterior
abdominalwal land commence their journey superiorly
from approximately two thirds of the way along the
inguinal ligament closer to the symphysis pubis. Care
needs to be taken to avoid them while using accessory
trochars during laparoscopy and to ensure that they
are identified when making a Maylard incision of the
abdominal wall.
The anterior abdominal wall
Beneath the skin and the fat of the superficialanterior
abdominalwal ll ies a sheath and combination of muscles
including the rectus abdominus, external and internal
oblique and tranversalis muscles (Fig. 1.2). Where these
muscles coalesce in the midline, the linea alba is formed.
Pyramidalis muscle is present in almost all women originating
on the anterior surface of the pubis and inserting
into the linea alba. The exact configuration of the muscles
encountered by the surgeon depends on exactly where any
incision is made.
The umbilicus
The umbilicus is essentially a scar made fromthe remnants
of the umbilical cord. It is situated in the linea alba and in a
variable position depending on the obesity of the patient.
However the base of the umbilicus is always the thinnest
part of the anterior abdominalwal land is the commonest
site of insertion of the primary port in laparoscopy.
The urachus is the remains of the allantois from the fetus
and runs from the apex of the bladder to the umbilicus