Abdominal Muscles

Question 1

External Oblique

Answer 1

O: External surface ribs 5-12

I: Linea alba, pubic tubercle, anterior half of iliac crest

N: Thoracoabdominal nerves (T7-12 APRs); Subcostal nerve (T12)

A: Compress + support ab viscera flex + contralateral rotation

Question 2

Internal Oblique

Answer 2

O: Thoracolumbar fascia, anterior 2/3 of iliac crest, lateral 1/3 of inguinal ligament

I: Inferior border of ribs 10-12, linea alba, pecten pubis via conjoint tendon

N: Thoracoabdominal nerves (T7-12 APRs), Iliohypogastric/Ilioinguinal nerves (L1)

A: Compress + support ab viscera, flexion + ipsilateral rotation

Question 3

Transverse Abdominal

Answer 3

O: Internal surfaces of costal cartilage 7-12, thoracolumbar fascia, iliac crest, 1/3 of inguinal ligament

I: Linea alba (w/ aponeurosis of internal oblique), pubic crest, pecten pubis via conjoint tendon

N: Thoracoabdominal nerves (T7-12 APRs), Iliohypogastric (L1)

A: Compress + support ab viscera

Question 4

Rectus Abdominis

Answer 4

O: Pubic symphysis and crest

I: Xiphoid process, Costal cartilage 5-7

N: Thoracoabdominal nerves (T7-12 APRs)

A: Flexes trunk (lumbar vertebrae), compress abdominal viscera