The middle sacral artery is the continuation of abdominal aorta after the terminal branches of internal iliac artery and runs under the sacral vertebrae and further continues as the median coccygeal artery.
If middle sacral artery is absent it is replaced by the lateral sacral artery which is branch of short common trunk of internal iliac artery.
It arises from the dorsal face of the aorta at the angle of divergence of the internal iliacus backward on the ventral face of the sacrum and is continued as the middle coccygeal artery.