Scapular Region and Posterior Arm

Question 1

The supraspinatus initiates _______ of the arm.

Answer 1

abduction

Question 2

What nerve supplies the trapezius?

Answer 2

Spinal accessory nerve (cranial nerve XI)

Question 3

Which two bones make up the shoulder girdle?

Answer 3

Scapula and clavicle.

Question 4

What is the action of the anterior arm compartment? What nerve innervates it?

Answer 4

Flex arm at shoulder and elbow. Musculocutaneous nerve.

Question 5

What is the action of the posterior arm compartment? What nerve innervates it?

Answer 5

Extend forearm at the elbow. Radial nerve.

Question 6

What is the action of the anterior forearm compartment? What nerve innervates it?

Answer 6

Flex forearm, wrist, and digits, and also pronate the forearm. Median and ulnar nerve innervation.

Question 7

What is the action of the posterior forearm compartment? What nerve innervates it?

Answer 7

Extend the forearm and digits, supinate the forearm. Radial nerve innervation.

Question 8

The coracoid process, acromion, spine, and glenoid fossa are all features of the ________.

Answer 8

scapula

Question 9

With which part of the sternum does the clavicle articulate?

Answer 9

the manubrium of the sternum

Question 10

What are the possible movement directions of the sternoclavicular joint?

Answer 10

Elevation/depression, protraction/retraction, circumduction.

Question 11

Name the two coracoclavicular ligaments.

Answer 11

Conoid and trapezoid ligaments

Question 12

Is the scapulothoracic joint actually a joint?

Answer 12

Not really

Question 13

What are the possible directions of movement at the scapulothoracic joint?

Answer 13

Protraction/retraction, elevation/depression, rotation

Question 14

Describe the Group 1, Group 2, and Group 3 muscles of the shoulder.

Answer 14

Group 1 muscles are the ones that originate on the body and attach to the humerus.

Group 2 muscles originate on the body and attach to the scapula.

Group 3 muscles include the girdle muscles to the humerus and the rotator cuff muscles.

Question 15

The supraspinatus muscle acts to _________ the shoulder to around 15 degrees, after which the deltoid takes over.

Answer 15

abduct

Question 16

Where on the humerus is a fracture most likely to occur?

Answer 16

The surgical neck

Question 17

To achieve 180 degrees of abduction at the shoulder, roughly ____ degrees occurs at the glenohumeral joint while the other _____ degrees occurs at the ___________ joint.

Answer 17

120 occurs at the glenohumeral joint while 60 occurs at the scapulothoracic joint

Question 18

Name the four rotator cuff muscles.

Answer 18

Supraspinatus, infraspinatus, subscapularis, teres minor.

Question 19

Why isn’t teres major considered a rotator cuff muscle?

Answer 19

Because it doesn’t insert on the humeral head, it inserts below near the anteromedial aspect of the surgical neck.

Question 20

Surgical ligation of the subclavian-axillary artery is possible due to extensive anastomotic connections of the scapula. Which three arteries participate in supplying the scapula after ligation and which artery reverses its flow to drain, instead of supply the region?

Answer 20

These supply the scapula:

1. Intercostal arteries
2. Suprascapular artery
3. Transverse cervical arteries

The suprascapular artery flow will reverse so that it drains, instead of supplies the scapular region.

Question 21

Fracture of the surgical neck of the humerus may injure which two structures?

Answer 21

Axillary nerve and posterior humeral circumflex as they pass through the quadrangular space.

Question 22

Can rotator cuff rupture or tendinitis occur as a result of falling on an outstretched arm or chronic wear-and-tear?

Answer 22

Yeah