The structure indicated is the median sacral artery.

The median sacral artery arises just above the bifurcation of the aorta into the common iliac arteries. The abdominal aorta gives off anterior, posterior and lateral branches.

The anterior branches include:

• Celiac trunk
• Superior mesenteric artery
• Gonadal arteries
• Inferior mesenteric arteries

Lateral branches:

• Middle suprarenal arteries
• Renal arteries

Posterior branches:

• Inferior phrenic arteries
• Lumbar arteries
• Median sacral arteries

The median sacral artery supplies the coccyx, the lumbar vertebrae and the sacrum.