Intermediate

Question 1

What 3 muscles make up the intermediate layer of the back?

Answer 1

1.) Serratus posterior superior
2.) Serratus posterior inferior
3.) Levator Costorum

Question 2

What nerves innervate the intermediate layer of the back?

Answer 2

Dorsal rami of C8-T11 ( levator costorum)
Ventral Rami of T1-T4 ( SPS)
Ventral Rami of T9-12 (SPI)

Question 3

What two muscles are innervated by ventral rami?
What muscle is innervated by dorsal rami?

Answer 3

Serratus posterior superior + inferior
Levator costorum

Question 4

What are the origins and insertions for these 3 muscles?

Answer 4

1.) Serratus posterior superior
O: SP C7-T2/3 + Ligamentum nuchae
I: superior surfaces of ribs 2-5

2.) Serratus posterior inferior
O: SP T11-L2
I: inferior reface of robe 9-12

3.) Levator costorum
O: Tips of TVPs C7-T11
I: inferior lateral to rib below

Question 5

All of these muscles insert onto a rib.
1.) what muscle inserts onto the superior surface of ribs?
2.) what muscle inserts Inferiorly + laterally to the rib below?
3.) what muscle insets onto the inferior surface of ribs?

Answer 5

1.) Serratus posterior superior
2.) Levator costorum
3.) Serratus posterior inferior