Extrinsic Back Muscles

Question 1

What muscles make up the rotator Cuff?

Answer 1

Supraspinatus

Infraspinatus

Teres Minor

Subscapularis

Question 2

What is the proximal attachment for the trapezius?

Answer 2

Medial third of superficial nuchal line

Nuchal ligament

External Occipital Protuberance

Spinous processes of C7 -T12

Question 3

What does the trapezius attach the pectoral girdle to?

Answer 3

It attaches the pectoral girdle to the cranium and vertebral column

Question 4

What are the three fibers that the trapezius is divided into?

Answer 4

Descending fiber (Elevates scapula when squaring shoulders)

Intermediate fiber (retracts scapulas posteriorly)

Ascending fiber (depresses scapulas and lower shoulders)

Question 5

What is the trapezius innervated by?

Answer 5

• Spinal Accessory Nerve/ Cranial Nerve CN XI (motor nerve)

Descends the neck onto the deep surface of the muscle

C3 and C4 spinal nerves (pain and proprioreceptive)

Part of Cervical Plexus( C1-C4) formed by ventral rami of upper cervical nerves

Question 6

Where does the descending fibers of the trapezius insert?

Answer 6

The lateral third of the clavicle and the acromion

Question 7

The intermediate and ascending fibers of the trapezius insert where?

Answer 7

On the spine of the scapula

Question 8

What do the ascending and descending fibers of the trapezius work together to do?

Answer 8

To raise the lateral aspect of the scapula upward

ie. Raising your arm above your head

Question 9

What is the blood supply for the trapezius?

Answer 9

The blood supply to the trapezius is from the superficial branch of the transverse cervical artery, the acromial branch of the suprascapular artery, and the dorsal branches of posterior intercostal arteries.

Question 10

What makes up the triangle of auscultation?

Answer 10

Inferiorly Latissimus dorsi (bottom of triangle)

Superiorly Lateral border of trapezius

Rhomboid major muscle

Scapula laterally