The median sacral artery, not just "median artery," arises from the abdominal aorta. Specifically, it emerges from the posterior aspect of the aorta at the level of the lower quarter of the third lumbar vertebra, or just above the bifurcation of the aorta.
Detailed Explanation
The median sacral artery is a small, unpaired artery that's a direct continuation of the abdominal aorta. It's essentially the terminal, caudal continuation of the aorta. Here’s a breakdown of its origin and course:
- Origin: Arises from the posterior aspect of the abdominal aorta, usually at the level where the aorta bifurcates into the common iliac arteries (approximately the lower part of the L3 vertebra).
- Course: Descends in the midline, anterior to the L4 and L5 vertebrae, the sacrum, and the coccyx.
- Termination: Ends in the glomus coccygeum, also known as the coccygeal gland, a small mass of vascular tissue located anterior to the coccyx.
It is important not to confuse this with other arteries that might contain the word "median" or are related to the aorta, such as branches off the aortic arch, or other arteries further down the arterial tree.
