Which vessel runs along the medial side of the psoas muscle and underneath the inguinal ligament?

The External Iliac Artery runs along the medial side of the psoas muscle and passes underneath the inguinal ligament as it transitions into the Common Femoral Artery. This anatomical course is significant in vascular studies and procedures because it plays a key role in supplying blood to the lower extremities. Understanding the placement of the External Iliac Artery relative to the psoas muscle is crucial for various medical contexts, such as interpreting ultrasound images or planning for interventions in the pelvic and lower limb regions.

Other vessels listed, like the Common Femoral Artery, begin where the External Iliac Artery ends, so they do not run along the medial side of the psoas muscle or under the inguinal ligament in the same manner. The Internal Iliac Artery branches off the common iliac arteries to supply the pelvic organs and runs posteriorly to the psoas muscle. The Superior Mesenteric Artery, on the other hand, arises from the abdominal aorta but is not closely associated with the psoas muscle or the inguinal ligament, as it supplies blood to the intestines rather than the lower limbs. Each of these arteries has distinct anatomical courses and functions, further clarifying why the External Ili