Descending aorta

In human anatomy, the descending aorta is part of the aorta, the largest artery, situated in the chest. It is the continued portion of the aorta immediately following the aortic arch.

Descending aorta
Plan of the branches.
The thoracic aorta, viewed from the left side.
Details
Precursor	Dorsal aorta
Source	Ascending aorta
Branches	Thoracic aorta Abdominal aorta
Identifiers
Latin	aorta descendens, pars descendens aortae
TA98	A12.2.10.001
TA2	4185
FMA	3784
Anatomical terminology [edit on Wikidata]

The descending aorta begins at the aortic arch and runs down through the chest and abdomen. The descending aorta anatomically consists of two portions or segments, the thoracic and the abdominal aorta, in correspondence with the two great cavities of the trunk in which it is situated. Within the abdomen, the descending aorta branches into the two common iliac arteries which serve the pelvis and, eventually, the legs.

The ductus arteriosus connects to the junction between the pulmonary artery and the descending aorta in foetal life. This artery later regresses as the ligamentum arteriosum.^[1][2]

Structure

Main article: Aorta

The descending aorta is made up of multiple parts that extend from the chest to the abdomen. The specific name changes depending on location. The descending thoracic aorta becomes the descending abdominal aorta once it reaches the diaphragm. It is preceded by the ascending aorta.

The descending aorta is composed of three layers. The inner layers is the tunica intima which regulates blood pressure. The middle layers is the media, which moves blood in one direction. The outer layer is the adventitia which provides structure and support.^[3]

The diameter of the descending aorta varies largely based on sex and age.

Function

The anatomical segments of the aorta.

The aorta transports oxygenated blood from the heart to the entire body.^[4] As the aorta descends down the body, it branches into smaller arteries. The descending thoracic aorta branches into the following (descending order)

• Bronchial arteries
• Esophageal arteries
• Mediastinal arteries
• Pericardial arteries
• Superior phrenic arteries

The branches of the descending abdominal aorta include (descending order)

• Inferior phrenic arteries
• Celiac trunk arteries
• Superior mesenteric arteries
• Middle suprarenal arteries
• Renal arteries
• Gonadal arteries
• Lumbar arteries
• Inferior mesenteric arteries
• Median sacral arteries
• Common iliac arteries