human anatomy Human anatomy (gr. ἀνατομία, "dissection", from ἀνά, "up", and τέμνειν, "cut") is primarily the scientific study of the morphology of the human body. Anatomy is subdivided into gross anatomy and microscopic anatomy. Gross ...

, the abdominal aorta is the largest

artery An artery () is a blood vessel in humans and most other animals that takes oxygenated blood away from the heart in the systemic circulation to one or more parts of the body. Exceptions that carry deoxygenated blood are the pulmonary arteries in ...

in the

abdominal cavity The abdominal cavity is a large body cavity in humans and many other animals that contain Organ (anatomy), organs. It is a part of the abdominopelvic cavity. It is located below the thoracic cavity, and above the pelvic cavity. Its dome-shaped roo ...

. As part of the

aorta The aorta ( ; : aortas or aortae) is the main and largest artery in the human body, originating from the Ventricle (heart), left ventricle of the heart, branching upwards immediately after, and extending down to the abdomen, where it splits at ...

, it is a direct continuation of the

descending aorta In human anatomy, the descending aorta is part of the aorta, the largest artery in the body. The descending aorta begins at the aortic arch and runs down through the chest and abdomen. The descending aorta anatomically consists of two portions o ...

(of the

thorax The thorax (: thoraces or thoraxes) or chest is a part of the anatomy of mammals and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main di ...

Structure

The abdominal aorta begins at the level of the diaphragm, crossing it via the aortic hiatus, technically behind the diaphragm, at the vertebral level of T12. It travels down the posterior wall of the abdomen, anterior to the vertebral column. It thus follows the curvature of the lumbar vertebrae, that is, convex anteriorly. The peak of this convexity is at the level of the third lumbar vertebra (L3). It runs parallel to the

inferior vena cava The inferior vena cava is a large vein that carries the deoxygenated blood from the lower and middle body into the right atrium of the heart. It is formed by the joining of the right and the left common iliac veins, usually at the level of the ...

, which is located just to the right of the abdominal aorta, and becomes smaller in diameter as it gives off branches. This is thought to be due to the large size of its principal branches. At the 11th rib, the diameter is 122mm long and 55mm wide and this is because of the constant pressure. The abdominal aorta is clinically divided into 2 segments: # The suprarenal abdominal or paravisceral segment, inferior to the diaphragm but superior to the renal arteries. # The Infrarenal segment, inferior to the renal arteries and superior to the iliac bifurcation.

Branches

The abdominal aorta supplies blood to much of the abdominal cavity. It begins at T12 and ends at L4 with its bifurcation into the common iliac arteries and usually has the following branches: The bifurcation (union) of the

is at L5 and therefore below that of the bifurcation of the aorta. # inferior phrenic a. # celiac a. ## left gastric a. ## splenic a. ### short gastric arteries (6) ### splenic arteries (6) ### left gastroepiploic a. ### pancreatic arteries ## common hepatic a. ### right gastric a. ### gastroduodenal a. #### right gastroepiploic a. #### superior pancreaticoduodenal a. ### right hepatic a. #### cystic a. ### left hepatic a. # superior mesenteric a. ## inferior pancreaticoduodenal a. ## jejunal and ileal arteries ## middle colic a. ## right colic a. ## ileocolic a ### anterior cecal a. ### posterior cecal a. – appendicular a. ### ileal a. ### colic a. # middle suprarenal a. # renal a. # testicular or ovarian a. # four lumbar arteries # inferior mesenteric a. ## left colic a. ## sigmoid arteries (2 or 3) ## superior rectal a. # median sacral a. # common iliac a. ## external iliac a. ## internal iliac a.

Relations

The abdominal aorta lies slightly to the left of the midline of the body. It is covered, anteriorly, by the

lesser omentum The lesser omentum (small omentum or gastrohepatic omentum) is the double layer of peritoneum that extends from the liver to the lesser curvature of the stomach, and to the first part of the duodenum. The lesser omentum is usually divided into t ...

and

stomach The stomach is a muscular, hollow organ in the upper gastrointestinal tract of Human, humans and many other animals, including several invertebrates. The Ancient Greek name for the stomach is ''gaster'' which is used as ''gastric'' in medical t ...

, behind which are the branches of the celiac artery and the

celiac plexus The celiac plexus, also known as the solar plexus because of its radiating nerve fibers, is a nerve plexus, complex network of nerves located in the abdomen, near where the celiac trunk, superior mesenteric artery, and renal arteries branch fro ...

; below these, by the lienal vein (splenic vein), are the

pancreas The pancreas (plural pancreases, or pancreata) is an Organ (anatomy), organ of the Digestion, digestive system and endocrine system of vertebrates. In humans, it is located in the abdominal cavity, abdomen behind the stomach and functions as a ...

, the left

renal vein The renal veins in the renal circulation, are large-calibre veins that drain blood filtered by the kidneys into the inferior vena cava. There is one renal vein draining each kidney. Each renal vein is formed by the convergence of the interlobar v ...

, the inferior part of the

duodenum The duodenum is the first section of the small intestine in most vertebrates, including mammals, reptiles, and birds. In mammals, it may be the principal site for iron absorption. The duodenum precedes the jejunum and ileum and is the shortest p ...

, the

mesentery In human anatomy, the mesentery is an Organ (anatomy), organ that attaches the intestines to the posterior abdominal wall, consisting of a double fold of the peritoneum. It helps (among other functions) in storing Adipose tissue, fat and allowi ...

, and the aortic plexus. Posteriorly, it is separated from the lumbar vertebrae and intervertebral fibrocartilages by the anterior longitudinal ligament and left lumbar veins. On the right side it is in relation above with the azygos vein, cisterna chyli,

thoracic duct In human anatomy, the thoracic duct (also known as the ''left lymphatic duct'', ''alimentary duct'', ''chyliferous duct'', and ''Van Hoorne's canal'') is the larger of the two lymph ducts of the lymphatic system (the other being the right lymph ...

, and the right crus of the diaphragm—the last separating it from the upper part of the

, and from the right celiac ganglion; the inferior vena cava is in contact with the aorta below. On the left side are the left crus of the diaphragm, the left celiac ganglion, the ascending part of the duodenum, and some coils of the

small intestine The small intestine or small bowel is an organ (anatomy), organ in the human gastrointestinal tract, gastrointestinal tract where most of the #Absorption, absorption of nutrients from food takes place. It lies between the stomach and large intes ...

Relationship with inferior vena cava

The abdominal aorta's venous counterpart, the

(IVC), travels parallel to it on its right side. * Above the level of the umbilicus, the aorta is somewhat posterior to the IVC, sending the right renal artery travelling behind it. The IVC likewise sends its opposite side counterpart, the left renal vein, crossing in front of the aorta. * Below the level of the umbilicus, the situation is generally reversed, with the aorta sending its right

common iliac artery The common iliac artery is a large artery of the abdomen paired on each side. It originates from the aortic bifurcation at the level of the 4th lumbar vertebra. It ends in front of the sacroiliac joint, one on either side, and each bifurcates ...

to cross its opposite side counterpart (the left

common iliac vein In human anatomy, the common iliac veins are formed by the external iliac veins and internal iliac veins. The left and right common iliac veins come together in the abdomen at the level of the lumbar vertebrae, fifth lumbar vertebra, forming the ...

) anteriorly.

Collateral circulation

The collateral circulation would be carried on by the anastomoses between the

internal thoracic artery The internal thoracic artery (ITA), also known as the internal mammary artery, is an artery that supplies the anterior chest wall and the breasts. It is a paired artery, with one running along each side of the sternum, to continue after its bifurc ...

and the

inferior epigastric artery In human anatomy, the inferior epigastric artery is an artery that arises from the external iliac artery. It is accompanied by the inferior epigastric vein; inferiorly, these two inferior epigastric vessels together travel within the lateral um ...

; by the free communication between the superior and inferior mesenterics, if the ligature were placed between these vessels; or by the anastomosis between the

inferior mesenteric artery In human anatomy, the inferior mesenteric artery (IMA) is the third main branch of the abdominal aorta and arises at the level of L3, supplying the large intestine from the distal transverse colon to the upper part of the anal canal. The region ...

and the

internal pudendal artery The internal pudendal artery is one of the three pudendal arteries. It branches off the internal iliac artery, and provides blood to the external genitalia. Structure The internal pudendal artery is the terminal branch of the anterior trunk ...

, when (as is more common) the point of ligature is below the origin of the

; and possibly by the anastomoses of the lumbar arteries with the branches of the internal iliac artery.

Clinical significance

Aneurysm

Additional images

File:Abdominal aorta.jpg, Contrast enhanced MRA of the abdominal aorta demonstrating normal paired arteries. File:Gray533.png, The celiac artery and its branches; the stomach has been raised and the peritoneum removed. File:Gray1097.png, Transverse section through the middle of the first lumbar vertebra, showing the relations of the pancreas. File:CT scan showing liver and kidney.jpg, CT scan showing the liver and a kidney File:Contrast-enhanced CT scan demonstrating abdominal aortic aneurysm.jpg, A transverse contrast enhanced CT scan demonstrating an abdominal aortic aneurysm of 4.8 by 3.8 cm File:Ultrasonographic measurement of aortic diameter at the navel.svg, The standard aortic measurement on abdominal ultrasonography, such as used for

abdominal aortic aneurysm Abdominal aortic aneurysm (AAA) is a localized enlargement of the abdominal aorta such that the diameter is greater than 3 cm or more than 50% larger than normal. An AAA usually causes no symptoms, except during rupture. Occasionally, abdo ...

s, is between the outer margins of the aortic wall. File:Abdominal aorta 2.jpg, Abdominal aorta File:Abdominal aorta ultrasound.jpg, Abdominal aorta ultrasound

References

External links

UCC
{{DEFAULTSORT:Abdominal Aorta Arteries of the abdomen Aorta