Human Anatomy, Part 2 - K. A. Dyubenko, A. K. Kolomiytsev, Yu. B. Chaykovsky 2008

Special Part
Cardiovascular system, systema cardiovasculare - Special Part
Blood vessels of the systemic circulation - Abdominal part of the aorta and its branches

The abdominal part of the aorta, pars abdominalis aortae (see Fig. 42), is the continuation of the Thoracic Aorta, measuring 13-14 cm in length. It lies in the retroperitoneal space below the Diaphragm. The upper boundary of the Abdominal Aorta corresponds to the level of the 12th thoracic vertebra, and the lower boundary corresponds to the 4th-5th lumbar vertebrae.

To the right lies the INFERIOR VENA CAVA, v. cava inferior. In its upper part, the anterior surface of the aorta is related to the body of the Pancreas, the splenic vein, v. lienalis, and the left renal vein, v. renalis sinistra. Below the body of the pancreas, the horizontal part of the duodenum crosses anterior to the aorta, and further inferiorly lies the ROOT of the mesentery of the Small Intestine.

The abdominal aorta gives rise to parietal and visceral branches. The parietal branches, rami parietales, are paired, with the sole exception of the median sacral artery, a. sacralis mediana. The visceral branches, rami viscerales, are subdivided into unpaired and paired groups.

Parietal Branches of the Abdominal Aorta:

1. A. phrenica inferior;

2. Aa. lumbales;

3. A. sacralis mediana.

1. The inferior phrenic artery, a. phrenica inferior (Fig. 42), arises from the aorta as the latter emerges from the aortic hiatus of the diaphragm. The inferior phrenic artery supplies Blood to the diaphragm, Esophagus, and pancreas. It gives off the superior suprarenal artery, a. suprarenalis superior, to the Adrenal gland. The inferior phrenic artery anastomoses with the corresponding superior Arteries, the lower intercostal arteries, the internal thoracic arteries, and esophageal branches.

2. The lumbar arteries, aa. lumbales (Fig. 42), are four pairs of branches arising symmetrically from the posterior wall of the abdominal aorta at the level of the 12th thoracic vertebra and terminating at the level of the 4elfth lumbar vertebral body. The lumbar arteries divide into posterior and anterior branches.

* The 1st and 2nd intercostal spaces are supplied by the supreme intercostal artery, a. intercostalis suprema (a branch of the costocervical trunk).

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Fig. 42. Abdominal part of the aorta, pars abdominalis aortae (anterior view).

The posterior branch supplies the Muscles and Skin of the back, and also gives off a spinal branch, r. spinalis, which supplies the Spinal Cord and its Meninges. The lumbar arteries anastomose with the intercostal and inferior hypogastric arteries.

3. The median sacral artery, a. sacralis mediana (Fig. 42), is a slender, unpaired arterial branch representing the direct continuation of the abdominal aorta. It runs down the anterior surface of the sacrum to the coccyx, where it terminates in the coccygeal body, glomus coccygeum. The median sacral artery supplies the sacrum, the piriformis and coccygeus muscles, and the posterior wall of the rectum.