Posterior Abdominal Wall Muscles

Question 1

psoas (origin)

Answer 1

transverse processes, bodies, and intervertebral discs of 12th thoracic and five lumbar vertebrae

Question 2

psoas (insertion)

Answer 2

with iliacus into lesser trochanter of femur

Question 3

psoas (nerve)

Answer 3

lumbar plexus

Question 4

psoas (action)

Answer 4

flexes thigh on trunk; if thigh is fixed, it flexes trunk on thigh, as in sitting up from lying down

Question 5

quadratus lumborum (origin)

Answer 5

iliolumbar ligament, iliac crest, tips of transverse processes of lower lumbar vertebrae

Question 6

quadratus lumborum (insertion)

Answer 6

12th rib

Question 7

quadratus lumborum (nerve)

Answer 7

lumbar plexus

Question 8

quadratus lumborum (action)

Answer 8

fixes 12th rib during inspiration; depressed 12th rib during forced expiration; laterally flexes vertebral column on the same side

Question 9

iliacus (origin)

Answer 9

iliac fossa

Question 10

iliacus (insertion)

Answer 10

with psoas into lesser trochanter of femur

Question 11

iliacus (nerve)

Answer 11

femoral nerve

Question 12

iliacus (action)

Answer 12

flexes thigh on trunk; if thigh is fixed, it flexes trunk on thigh, as in sitting up from lying down