Muscles & Innervations of Torso

Question 1

External Obliques

Answer 1

Anterior Abdominal Wall

Bilateral- Anterior flexion of trunk
Unilateral- Lateral flexion, rotation

Innervated by segmental nerves T7-12

Inferior free edge is the inguinal ligament, fibers travel downward medially

Question 2

Internal Oblique

Answer 2

Anterior Abdominal Wall

Bilateral- Anterior flexion of trunk
Unilateral- Lateral flexion, rotation

Innervated by segmental nerves T7-12, L1

Inferior portion joins with transversus abdominus aponeurosis to form conjoint tendon

Question 3

Transversus abdominus

Answer 3

Anterior Abdominal Wall

Compress and support abdominal viscera

Segmental nerves T7-12, L1

Inferior portion joins with internal oblique to form conjoint tendon

Question 4

Rectus abdominus

Answer 4

Anterior Abdominal Wall

Flexion, tenses wall

Segmental nerves T7-12

Question 5

Psoas major

Answer 5

Posterior Abdominal Wall

Ventral rami L1-3

Flexes hip.

Joins with Iliacus to form iliopsoas

Question 6

Quadratus Lumborum

Answer 6

Posterior Abdominal Wall

Ventral rami T12-L4

Depresses & stabilizes rib 12, Lateral bending

Question 7

Iliacus

Answer 7

Posterior Abdominal Wall

Femoral Nerve

Flexes hip

Joins with psoas major to form iliopsoas