The intersegmental arteries are a set of 30 arteries arising from the embryonic

dorsal aorta The dorsal aortae are paired (left and right) embryological vessels which progress to form the descending aorta. The paired dorsal aortae arise from aortic arches that in turn arise from the aortic sac. The primary dorsal aorta is located deep t ...

, with each artery providing blood supply to one

somite The somites (outdated term: primitive segments) are a set of bilaterally paired blocks of paraxial mesoderm that form in the embryonic stage of somitogenesis, along the head-to-tail axis in segmented animals. In vertebrates, somites subdivide in ...

and its derivatives.

Cervical intersegmental arteries

The cervical intersegmental arteries merge into the

vertebral artery The vertebral arteries are major arteries An artery (plural arteries) () is a blood vessel in humans and most animals that takes blood away from the heart to one or more parts of the body (tissues, lungs, brain etc.). Most arteries carry o ...

with the exception of the 7th (or possibly the 6th) cervical intersegmental artery, which becomes the

subclavian artery In human anatomy, the subclavian arteries are paired major arteries of the upper thorax, below the clavicle. They receive blood from the aortic arch. The left subclavian artery supplies blood to the left arm and the right subclavian artery supplie ...

. The confusion arises because the vertebral artery drains into the subclavian artery following the disappearance of the dorsal aortae in part of the cervical region.

Thoracic intersegmental arteries

The thoracic intersegmental arteries all develop into the

intercostal arteries The intercostal arteries are a group of arteries that supply the area between the ribs ("costae"), called the intercostal space. The highest intercostal artery (supreme intercostal artery or superior intercostal artery) is an artery in the human ...

Lumbar intersegmental arteries

The lumbar intersegmental arteries develop into the

lumbar arteries The lumbar arteries are arteries located in the lower back or lumbar region. The lumbar arteries are in parallel with the intercostals. They are usually four in number on either side, and arise from the back of the aorta, opposite the bodies of ...

, with the exception of the 5th (last) lumbar intersegmental artery, which becomes the

common iliac arteries 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 in ...

Sacral intersegmental arteries

These arteries merge into the

lateral sacral artery The lateral sacral arteries is an artery in the pelvis that arises from the posterior division of the internal iliac artery. It later splits into two smaller branches, a superior and an inferior. Structure The lateral sacral artery is the seco ...

References

{{reflist Arteries