Intermediate Extrinsic Back Muscles

Question 1

Serratus posterior superior

Answer 1

Proximal- nuchal ligament; spinous processes of C7-T3 vertebrae

Distal- superior borders of ribs 2-4

Innervation- 2nd to 5th intercostal nerves

Actions- elevates ribs

Question 2

Serratus posterior inferior

Answer 2

Proximal- spinous processes of T11-L2

Distal- inferior border of ribs 8-12

Innervation- 9th-11th intercostal nerves; subcostal T12 nerve

Action- depresses ribs