Abdominal Aorta

Abdominal aorta

•      begins at the aortic hiatus of the diaphragm as a midline structure opposite the lower border  of TXII vertebra

•      Runs downward & slightly to the left infront of lumbar vertebra

•      Ends infront of lower part of body of L4 vertebra 1.25 left to the median plane

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Relations

  Anteriorly, from above downawrds:

•      Celiac plexus and ganglion

•      Body of the pancreas and splenic vein

•      Left renal vein clamped to the aorta by origin of superior mesenteric artery

•      Uncinate process of pancreas &3^rd part of duodenum

  Posteriorly:

•      Body of upper 4 lumbar vertebra & intervertebral disc

•      Left lumbar vein

  To the right side:

•      Inferior venacava with sympathetic chain behind it

•      Right crus of diphragm

•      Cisterna chyli & azygos vein in the upper part

  To the left side:

•      Left crus of diaphragm

•      Pancreas

•      Fourth part of duodenum

•      Left sympathetic chain

Branches

  

Arterial supply of gut

Coeliac trunk

•      Artery of foregut

•      Arises from front of the abdominal aorta at the level of disc betwn T12 & L1 vertebra

•      About 1.25 cm long

•      Divided into 3 terminal branches namely:

•      Left gastric, hepatic & splenic artery

Superior mesenteric artery  

Artery of midgut

Arises from front of abdominal aorta at the level of L1 vertebra

First lies behind the body of pancreas, then front of uncinate process

Crosses the third part of duodenum & enters the root of mesentery where it crosses inferior venacava, rt. ureter & right psoas

Inferior mesenteric artery  

•      Artery of hind gut

•      Arise from the front of the abdominal aorta at the level of L3

•      Run down & to the left behind the peritoneum

•      Crosses the common iliac artery

•      Medial to the left ureter

Common iliac artery

•      Terminal branches of abdominal aorta

•      Begins infront of L4 vertebra 1.25 cm left to the median plane

•      Passes downward & laterally

•      Ends infront of sacroliliac joint by dividing into external & internal iliac artery

Internal iliac artery

•      Smaller terminal branch of common iliac artery

•      Supplies the pelvic organ, perineum, greater part of gluteal region & iliac fossa

•      In foetus it is large because it transmits blood to placenta through umbilical artery

•      Later, umbilical artery persists to form first part of superior vesical artery & rest degenerate to form medial umbilical ligament

Branches