Posterior intercostal arteries
|Artery: Posterior intercostal arteries|
The thoracic aorta, viewed from the left side. (Intercostals visible at right.)
|Latin||arteriae intercostales posteriores|
|Source||1-2: supreme intercostal
|Vein||Posterior intercostal veins|
There are eleven posterior intercostal arteries on each side.
- The 1st and 2nd posterior intercostal arteries arise from the supreme intercostal artery, a branch of the costocervical trunk of the subclavian artery.
- The lower nine arteries are the aortic intercostals, so called because they arise from the back of the thoracic aorta.
The right aortic intercostals are longer than the left because of the position of the aorta on the left side of the vertebral column; they pass across the bodies of the vertebrae behind the esophagus, thoracic duct, and azygos vein, and are covered by the right lung and pleura.
The left aortic intercostals run backward on the sides of the vertebrae and are covered by the left lung and pleura; the upper two vessels are crossed by the left superior intercostal vein, the lower vessels by the hemiazygos vein.
Each artery then divides into an anterior and a posterior ramus.
A given posterior intercostal artery travels along the bottom of the rib with its corresponding posterior intercostal vein, as well as the intercostal nerve of the given space. The vein is superior to the artery, and the intercostal nerve is inferior to it. Commonly, the mnemonic, "Van," is used to recall the order of the vein, artery and nerve, from superior to inferior.
- Anatomy figure: 21:06-06 at Human Anatomy Online, SUNY Downstate Medical Center - "Branches of the ascending aorta, arch of the aorta, and the descending aorta."
- thoraxlesson5 at The Anatomy Lesson by Wesley Norman (Georgetown University) (paravertebralregion)
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