Muscles of the Thoracic Wall

Question 1

Serratus Posterior superior OIAN

Answer 1

O: Spinous processes of C7-T3
I: superior borders of ribs 2-5
A: Proprioception, rib elevation
N: 2nd-5th intercostal nerves, ventral rami or thoracic spinal nerves 2-5

Question 2

Serratus Posterior Inferior OIAN

Answer 2

O: Spinous processes of T11-L2
I: inferior borders of 8th-12th rib.
A: Proprioception, rib elevation
N: anterior rami of T9-T12 spinal nerves

Question 3

Levator Costarum OIAN

Answer 3

O: Transverse processes of C7-T11
I: subjacent ribs between tubercle and angle
A: elevates ribs
N: dorsal rami of C8-T11 NOT !VENTRAL!

Question 4

External, Internal, and Innermost Intercostals AN

Answer 4

Ventral rami of T1-T11 (Intercostal nerve)

“No action”

Question 5

Subcostal OIAN

Answer 5

O: Internal Surface of lower ribs near their angle
I: superior border of 2nd- 3rd ribs below
A: Elevates ribs?
N: Ventral rami of T1-T11 (Intercostal nerve)

Question 6

Transversus Abdominus OIAN

Answer 6

O: Posterior surface of lower sternum
I: Internal Surface of Costal cartilages 2-6
A: Depress ribs, possibly proprioception
N: Ventral rami of T1-T11 (Intercostal nerve)