Unit 1 - Back: Deep Muscles of the Posterior Neck (Ex. I)

Question 1

middle scalene

Answer 1

O: transverse processes of C1-C2; posterior tubercles of transverse processes of C3-C7
I: posterior to groove for subclavian artery on rib 1
Inn: direct branches from C and B plexuses (C3-C8)
A: w/ ribs mobile - elevates upper ribs (forced inspiration); w/ ribs fixed - ipsilaterally flexes C spine (unilateral) and flexes neck (bilateral)

Question 2

posterior scalene

Answer 2

O: posterior tubercles of transverse processes of C5-C7
I: outer surface of rib 2
Inn: direct branches from C and B plexuses (C3-C8)
A: w/ ribs mobile - elevates upper ribs (forced inspiration); w/ ribs fixed - ipsilaterally flexes C spine (unilateral) and flexes neck (bilateral)

Question 3

anterior scalene

Answer 3

O: anterior tubercles of transverse processes of C3-C6
I: scalene tubercle of rib 1
Inn: direct branches from C and B plexuses (C3-C8)
A: w/ ribs mobile - elevates upper ribs (forced inspiration); w/ ribs fixed - ipsilaterally flexes C spine (unilateral) and flexes neck (bilateral)