|After the gastrointestinal tract is removed, what you have left in the posterior abdomen are the cut edges of the peritoneum and the remaining peritoneum that covers the "retroperitoneal" structures.
It is worth while to take a look at this type of image to appreciate just how the various mesenteries are reflected from the posterior abdominal wall as well as the diaphragm.
|After the mesentery has been cleaned from the posterior abdominal wall, you can see the true retroperitoneal structures of the abdomen. These are the great vessels and their branches, sympathetics, kidneys and their ureters, and suprarenal glands.
You should be able to see the following structures:
|When the kidney is opened, you can see the following structures:
|Finally, with the kidneys and their related structures removed, you can see the muscles that make up the posterior abdominal wall and the branches of the the lower thoracic and lumbar nerves.
You should be able to point out the:
|The nerves of the posterior abdominal wall are branches of the lumbosacral plexus. This plexus is shown in the adjacent image.
You should be able to identify the roots of the plexus:
L1 gives rise to the iliohypogastric and ilioinguinal nerves.
L1 + L2 gives rise to the genitofemoral nerve
L2 + L3 gives rise to the lateral femoral cutaneous
L2 + L3 + L4 give rise to the femoral and obturator nerves
L4 + L5 give rise to the lumbosacral trunk which joins sacral nerves to form the sacral plexus.
|Immediately after the aorta enters the abdomen under the median arcuate ligament, it gives rise to its first paired branches, the inferior phrenic arteries.
You can break up the branches of the aorta into paired and unpaired branches. The unpaired branches are:
The paired branches supply the organs and muscular walls of the abdomen as well as pelvic structures and the lower limb. They are:
||The veins all drain into the inferior vena cava and thus back to the heart.
The major veins are:
|Superior & Inferior Mesenteric Arteries||Abdomen Homepage|
|This is copyrighted©1999 by Wesley Norman, PhD, DSc|