Shoulder

Question 1

What bones make up the pectoral girdle?

Answer 1

Scapula - posterior
Clavicle - anterior

Question 2

What is the major function of the pectoral girdle?

Answer 2

provide attachment for upper limb to the axial skeleton and movement flexibility

Question 3

What is the shape of the clavicle?

Answer 3

S shape

Question 4

What are the clavicle attachment sites (and name of each end)?

Answer 4

Medially: sternal end - attaches to manubrium of sternum
Laterally: acromial end - attaches to acromion process of scapula

Question 5

What are the major functions of the clavicle?

Answer 5

1. muscle attachment site
2. holds the scapulae and arms out laterally from the thorax

Question 6

What is the location of the scapulae?

Answer 6

dorsal ribcage - between rib 2 and 7

Question 7

How many anatomical borders does the scapula have? (describe them)

Answer 7

1. Superior border - short and sharp
2. Medial border - parallel to spinal column
3. Lateral border - thick, ends with glenoid cavity

Question 8

What is the glenoid cavity?

Answer 8

The scapulae’s joint cavity for articulation with humerus

Question 9

Describe the humerus’ proximal articulation

Answer 9

With glenoid cavity of scapula

Question 10

What is the shoulder joint called?

Answer 10

Glenohumeral joint

Question 11

Why is the shoulder prone to dislocation?

Answer 11

because the glenoid cavity is incredibly shallow

Question 12

List the posterior thorax muscles that act on the scapula

Answer 12

1. trapezius (considered as 3 muscles)
2. levator scapulae
3. rhomboids (major and minor) considered as 1 muscle

Question 13

List the anterior thorax muscles that act on the scapula

Answer 13

1. pectoralis minor
2. serratus anterior
3. subclavius

Question 14

What movements can the scapula perform?

Answer 14

1. elevation and depression
2. protraction and retraction
3. upward and downward rotation

Question 15

What is the origin of levator scapulae?

Answer 15

transverse processes of vertebrae C1-C4 (neck)

Question 16

What is the insertion of levator scapulae?

Answer 16

superior part of medial scapula

Question 17

What is the action of levator scapulae?

Answer 17

elevate scapula and tilts glenoid fossa inferiorly by rotating scapula

Question 18

What innervates the levator scapulae

Answer 18

Dorsal scapular nerve (C5)
Cervical nerves (C3-C4)

Question 19

What is the origin of trapezius?

Answer 19

medial 1/3 of superior nuchal line
external occipital protuberance
nuchal ligament
spinous processes of C7-T12 (head to end of ribcage)

Question 20

What is the insertion of trapezius?

Answer 20

lateral 1/3 of clavicle
acromion
spine of scapula

Question 21

What is the action of trapezius?

Answer 21

elevates (superior fibres), depresses (inferior fibres), retracts (medial fibres), and rotates scapula

Question 22

What nerve innervates the trapezius?

Answer 22

Accessory Nerve (CN XI) - cranial nerve not spinal nerve

Question 23

What is the origin of the rhomboid?

Answer 23

Minor: nuchal ligament and spinous processes of C7-T1
Major: spinous processes of T2-T5

Question 24

What is the insertion of the rhomboid?

Answer 24

Medial border of scapula

Question 25

What is the action of rhomboid?

Answer 25

Retracts scapula and rotates it to depress glenoid cavity Fixes scapula to thoracic wall

Question 26

What is the innervation of the rhomboid?

Answer 26

Dorsal scapular nerve

Question 27

What is the origin of pectoralis minor?

Answer 27

3rd to 5th ribs near their costal cartilages

Question 28

What is the insertion of pectoralis minor?

Answer 28

Coracoid process of the scapula

Question 29

What is the action of pectoralis minor?

Answer 29

stabilizes scapula by drawing it inferiorly and anteriorly against the thoracic wall

Question 30

What is the innervation of pectoralis minor?

Answer 30

medial pectoral nerve

Question 31

Serratus anterior origin

Answer 31

fleshy slips from upper ribs

Question 32

serratus anterior insertion

Answer 32

costal aspect of medial margin of scapula

Question 33

serratus anterior action

Answer 33

protracts and stabilizes scapula assists with upward rotation

Question 34

serratus anterior innervation

Answer 34

long thoracic nerve

Question 35

what muscle is known as the boxer's muscle?

Answer 35

serratus anterior

Question 36

what are the rotator cuff muscles?

Answer 36

1. subscapularis 2. supraspinatus 3. infraspinatus 4. teres minor

Question 37

what is the main role of the rotator cuff muscles?

Answer 37

help anchor the head of humerus into the glenoid cavity of the shoulder joint

Question 38

which rotator cuff muscle has a different insertion than the rest - and what are the insertions

Answer 38

subscapularis - inserts into lesser tubercle of humerus the rest insert into greater tubercle of humerus

Question 39

what nerves innervate the muscles of the rotator cuff - include the muscles

Answer 39

1. subscapular nerve - subscapularis 2. suprascapular nerve - supraspinatus and infraspinatus 3. axillary nerve - teres minor

Question 40

what is the action of subscapularis

Answer 40

primary medial rotator of humerus

Question 41

which two rotator cuff muscles have the same action, and what is the action

Answer 41

Infraspinatus and teres minor lateral rotation of humerus

Question 42

what is the action of the supraspinatus?

Answer 42

initiate abduction prevent downward dislocation of humerus