The median sacral artery arises from the abdominal aorta at the level of the bottom quarter of the third lumbar vertebra.

[1] It descends in the middle line in front of the fourth and fifth lumbar vertebrae, the sacrum and coccyx, ending in the glomus coccygeum (coccygeal gland).

It is crossed by the left common iliac vein and accompanied by a pair of venae comitantes; these unite to form a single vessel that opens into the left common iliac vein.

The median sacral artery is morphologically the direct continuation of the abdominal aorta.

This article incorporates text in the public domain from page 613 of the 20th edition of Gray's Anatomy (1918)