Muscles

Question 1

2 groups

Answer 1

Anterolateral group (3 muscles on each side):
1. External abdominal oblique 2. Internal abdominal obliques
3. Transversus abdominis
Anterior group (2 muscles on each side of median plane):
1. Rectus abdominis
2. Pyramidalis

Question 2

Common nerve supply

Answer 2

1. Lower 5 intercostal and subcostal (T12) nerves
2. Internal oblique and transversus abdominis have additional supply from 1st lumbar nerve

Question 3

Common action

Answer 3

1. Protect abdominal viscera and keep them in position
2. Increase intra-abdominal pressure helping in delivery, defecation, micturition, cough, and vomitting
3. Oblique muscles bend trunk lateral while rectus abdominis flexes it mainly from supine position
4. External oblique of one side and internal oblique of opposite side can do trunk lateral rotation