Abdominal Wall Muscles

Question 1

External Oblique

Answer 1

O: External surfaces of the 5th-12th Ribs
I: Linea Alba, Pubic Tubercle, and Anterior Half of Iliac Crest
N: Thoracoabdominal Nerves (T7-11 Spinal Nerve APRs) and Subcostal Nerve (T12)
A: compress and support abdominal viscera; flexion and contralateral rotation of the trunk

Question 2

Internal Oblique

Answer 2

O: Thoracolumbar Fascia, Anterior 2/3 of Iliac Crest, and Connective Tissue deep to Lateral 1/3 of Inguinal Ligament
I: Inferior borders of 10th-12th Ribs, Linea Alba, and Pecten Pubis via Conjoint Tendon
N: Thoracoabdominal Nerves (APR of inferior 6 Thoracic) and first Lumbar Nerves
A: compress and support abdominal viscera; flexion and ipsilateral rotation of the trunk; assists with lumbar stabilization

Question 3

Transverse Abdominis

Answer 3

O: Internal Surfaces of 7th-12th Costal Cartilages, Thoracolumbar Fascia, Iliac Crest, and Connective Tissue deep to Lateral 1/3 of Inguinal Ligament
I: Linea Alba with aponeurosis of Internal Oblique, Pubic Crest, and Pecten Pubis via Conjoint Tendon
N: thoracoabdominal (APR inferior 6 thoracic) and first Lumbar Nerve
A: compress and support abdominal viscera; Lumbar Stabilization

Question 4

Rectus Abdominis

Answer 4

O: Pubic Symphysis and Pubic Crest
I: Xiphoid Process and 5th-7th Costal Cartilages
N: Thoracoabdominal Nerves (APR of inferior 6 thoracic nerves)
A: compress abdominal viscera; flexion of the trunk; stabilizes and controls tilt of pelvis