Abdominal Muscles

Question 1

External oblique

Answer 1

Origin: posterolateral ribs 5-12
Insertion: iliac crest, linea alba
Action: flex, ipsilateral lateral flexion, contralat rot
Innervation: intercostal nerves T7-T12

Question 2

Internal oblique

Answer 2

Origin: iliac crest, thoracolumbar fascia
Insertion: linea alba, inferior ribs
Action: flex, ipsilateral lateral flexion, ipsilateral rotation
Innervation: intercostal nerves T7-T12

Question 3

Transverse abdominis

Answer 3

Origin: ribs 7-12, thoracolumbar fascia, iliac crest
Insertion: linea alba
Action: support abdominal wall, compress abdomen
Innervation: intercostal nerves T7-T12

Question 4

Rectus abdominus

Answer 4

Origin: ribs 5-7, xiphoid process
Insertion: pubic ramus
Action: flex
Innervation: intercostal nerves T7-T12