Page 120 - Clinical Anatomy

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The urinary tract 105

body. It has a thin fibrous capsule, to which the peritoneum adheres inti-
mately. The fibrous tissue of the capsule extends into the spleen to form a
series of trabeculae between which lies the splenic pulp.

Clinical features

1◊◊In performing a splenectomy the close relation of the pancreatic
tail to the hilum and splenic pedicle must be remembered; it is easily
wounded.
2◊◊Note the close proximity of the lower ribs, lowest part of the left lung
and pleural cavity, left diaphragm, left kidney and the spleen; injuries to the
left upper abdomen may damage any combination of these structures. Sim-
ilarly, a stab wound of the posterior left chest may penetrate the diaphragm
and tear the spleen. The spleen, with its thin tense capsule, is the common-
est intra-abdominal viscus to be ruptured by blunt trauma.
3◊◊Accessory spleens (one or more) may occur most commonly near the
hilum, but also in the tail of pancreas, the mesentery of the spleen, the
omentum, small bowel mesentery, ovary and even testis. They occur in
about one in ten subjects and, if left behind, may result in persistence of
symptoms following splenectomy for congenital acholuric jaundice or
thrombocytopenic purpura.

The urinary tract

The kidneys
The kidneys lie retroperitoneally on the posterior abdominal wall; the right
kidney is 0.5in (12mm) lower than the left, presumably because of its
downward displacement by the bulk of the liver. Each measures approxi-
mately 4.5in (11cm) long, 2.5in (6cm) wide and 1.5in (4cm) thick.

Relations (Figs 80, 81)
•◊◊Posteriorly—the diaphragm (separating pleura), quadratus lumborum,
psoas, transversus abdominis, the 12th rib and three nerves—the subcostal
(T12), iliohypogastric and ilio-inguinal (L1).
•◊◊Anteriorly —the right kidney is related to the liver, the 2nd part of
the duodenum (which may be opened accidentally in performing a right
nephrectomy), and the ascending colon. In front of the left kidney lie the
stomach, the pancreas and its vessels, the spleen, and the descending colon.
The suprarenals sit on each side as a cap on the kidney’s upper pole.
The medial aspect of the kidney presents a deep vertical slit, the hilum,
which transmits, from before backwards, the renal vein, renal artery,
pelvis of the ureter and, usually, a subsidiary branch of the renal artery.