The median sacral artery arises from the
abdominal aorta at the level of the bottom quarter of the
third lumbar vertebra. 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). Minute branches pass from it, to the posterior surface of the
rectum. On the last lumbar vertebra it
anastomoses with the lumbar branch of the
iliolumbar artery; in front of the sacrum it anastomoses with the
lateral sacral arteries, sending offshoots into the
anterior sacral foramina. 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.
Development The median sacral artery is morphologically the direct continuation of the abdominal aorta. It is
vestigial in humans, but large in animals with tails, such as the
crocodile. ==See also==