A patient with a knife wound in the left lumbal part was delivered to the emergency hospital. In course of operation a surgeon found that internal organs were not damaged but the knife injured one of muscles of renal pelvis. What muscle is it?

Answer options

1. Abdominal internal oblique muscle
2. Erector muscle of spine
3. Iliac muscle
4. Greater psoas muscle
5. Abdominal external oblique muscle

Explanation

The psoas major is a long fusiform muscle located on the side of the lumbar region of the vertebral column and brim of the lesser pelvis. It joins the iliacus muscle to form the iliopsoas. The psoas major is a major component of the renal bed together with other muscles such as the diaphragm, quadratus lumborum, and transverse abdominis muscle.