L2 Pectoral Girdle and Shoulder

Question 1

Which two parts make up the pectoral girdle?

Answer 1

Scapula and clavicle

Question 2

Which structure connects the axial skeleton to the upper limb?

Answer 2

Pectoral girdle

Question 3

The shoulder is an articulation between with two structures?

Answer 3

Glenoid cavity of scapula and the head of humerus

Question 4

Give the innervation and function of trapezius

Answer 4

Upper: Elevate scapula
Middle: Retract scapula
Lower: Depress scapula

Upper + lower fibres: Rotate scapula to direct glenoid cavity superiorly

Innervation: Spinal accessory nerve (CN XI)

Question 5

Give the innervation and function of deltoid

Answer 5

Middle: Abduction of shoulder beyond 15 degrees
Anterior: Flexion of shoulder
Posterior: Extension of shoulder

Innervation: Axillary nerve (C5, C6)

Question 6

Give the innervation and function of the rhomboids

Answer 6

Retract and rotate scapula to tilt glenoid cavity inferiorly

Innervation: Dorsal scapular nerve

Question 7

Give the innervation and function of levator scapulae

Answer 7

Elevate scapula and rotate to tilt glenoid cavity inferiorly

Innervation: Dorsal scapular nerve

Question 8

Give the innervation and function of teres major

Answer 8

Medial rotation and adduction of humerus

Innervation: Lower subscapular nerve

Question 9

Give the innervation and function of latissimus dorsi

Answer 9

Medial rotation, extension and adduction of shoulder

Raises body while climbing.

Innervation: Thoracodorsal nerve

Question 10

Give the innervation and function of serratus anterior

Answer 10

Protraction of scapula (reaching out/punching)

Holds scapula to chest wall

Rotation of scapula to tilt glenoid superiorly, allowing raising of arm

Innervation: Long thoracic nerve

Question 11

Give the innervation and function of pectoralis major and minor

Answer 11

Major: medial rotation and adduction of humerus
Innervation: medial and lateral pectoral nerves

Minor: Stabilises scapula
Innervation: medial pectoral nerve only

Question 12

Give the innervation and function of subscapularis

Answer 12

Medial rotation and adduction of humerus

Innervation: Upper and lower subscapular nerves

Question 13

Give the innervation and function of supraspinatus

Answer 13

Initiates abduction of shoulder (first 15 degrees)

Innervation: Suprascapular nerve

Question 14

Give the innervation and function of infraspinatus

Answer 14

Lateral rotation of humerus

Innervation: Suprascapular nerve

Question 15

Give the innervation and function of teres minor

Answer 15

Lateral rotation and adduction of humerus

Innervation: Axillary nerve (C5, C6)

Question 16

Which muscles of the pectoral girdle are innervated by the axillary nerve?

Answer 16

The axillary nerve (C5-C6) innervates the deltoid muscle and teres minor

Question 17

Which muscles of the pectoral girdle are medial rotators and adductors of humerus?

Answer 17

Teres major
Latissimus dorsi
Pectoralis major
Subscapularis

Question 18

Which muscles of the pectoral girdle abduct the humerus?

Answer 18

Supraspinatus
- initiates movement (first 15 degrees)

Deltoid
- abducts beyond 15 degrees

Question 19

Which muscles of the pectoral girdle laterally rotate the humerus?

Answer 19

Infraspinatus

Teres minor

Question 20

What is the origin and insertion of levator scapulae?

Answer 20

Origin: Occiput
Insertion: Superior angle of scapula

Question 21

What is the origin and insertion of rhomboid major?

Answer 21

Origin: T2-T5 spinous processes
Insertion: Medial border of scapula

Question 22

What is the origin and insertion of rhomboid minor?

Answer 22

Origin: C7-T1 spinous processes
Insertion: Medial border of scapula

Question 23

What is the origin and insertion of supraspinatus?

Answer 23

Origin: Supraspinous fossa of scapula
Insertion: Greater tubercle of humerus (superior facet)

Question 24

What is the origin and insertion of infraspinatus?

Answer 24

Origin: Infraspinous fossa of scapula
Insertion: Greater tubercle of humerus (middle facet)

Question 25

What is the origin and insertion of teres minor?

Answer 25

Origin: Lateral border of scapula Insertion: Greater tubercle of humerus (inferior facet)

Question 26

What is the origin and insertion of subscapularis?

Answer 26

Origin: Subscapular fossa of scapula Insertion: Lesser tubercle of humerus

Question 27

What is the origin and insertion of teres major?

Answer 27

Origin: Lateral border/inferior angle of scapula Insertion: Intertubercular sulcus of humerus (medial lip)

Question 28

What is the origin and insertion of latissimus dorsi?

Answer 28

Origin: Iliac crest, thoracic lumbar fascia, lower thoracic vertebrae Insertion: Intertubercular sulcus of humerus (floor) Originates on the posterior side of the body; inserts on the anterior side of the humerus.

Question 29

What is the origin and insertion of deltoid?

Answer 29

Origin: Spine of scapula, acromion, anterior side of clavicle (lateral one-third) Insertion: Deltoid tuberosity of humerus

Question 30

What is the origin and insertion of trapezius?

Answer 30

Origin: Occiput, nuchal line, spinous processes of C8-T12 Insertion: Lateral one-third of clavicle, acromion, spine of scapula

Question 31

What is the origin and insertion of serratus anterior?

Answer 31

Origin: Lateral surfaces of ribs 1-9 Insertion: Medial border of scapula (costal surface)

Question 32

What is the origin and insertion of pectoralis major?

Answer 32

Origin: Medial clavicle, sternum and upper costal cartilages Insertion: Intertubercular sulcus of humerus (lateral lip)

Question 33

What is the origin and insertion of pectoralis minor?

Answer 33

Origin: Ribs 3-5 Insertion: Coracoid process of scapula

Question 34

Damage to which nerve results in winged scapula?

Answer 34

Long thoracic nerve Damage usually caused by: - Penetrating injury to lateral chest - Iatrogenic (chest drain insertion, breast surgery) - Neuritis

Question 35

Which tendon is most commonly damaged in a rotator cuff injury?

Answer 35

Supraspinatus

Question 36

How do you test the function of the four rotator cuff muscles?

Answer 36

Supraspinatus: Abduct arm against resistance Infraspinatus: Laterally rotate arm against resistance Teres minor: Laterally rotate arm against resistance Subscapularis: Place dorsum of hand to mid-lumbar spine, then ask patient to lift hand off back (medial rotation)

Question 37

What structure prevents superior displacement of the humerus?

Answer 37

Coracoacromial arch

Question 38

Anterior dislocation of the shoulder joint is usually caused by excessive extension and lateral rotation of the humerus. Which nerve is commonly injured by anterior shoulder dislocation?

Answer 38

Axillary nerve (C5, C6)

Question 39

Which nerve is at risk from a surgical neck of humerus fracture?

Answer 39

Axillary nerve (C5, C6)

Question 40

What components form the coracoacromial arch?

Answer 40

Acromion + coracoid process + coracoacromial ligament

Question 41

What are the roots of the brachial plexus?

Answer 41

C5, C6, C7, C8 and T1

Question 42

What are the trunks of the brachial plexus?

Answer 42

Superior trunk (C5 + C6) Middle trunk (C7) Inferior trunk (C8 + T1)

Question 43

What are the divisions of the brachial plexus trunks?

Answer 43

Each trunk divides into an anterior and posterior division

Question 44

What are the cords of the brachial plexus? Which divisions form each one?

Answer 44

Lateral cord (anterior division of superior trunk + anterior division of middle trunk) Medial cord (anterior division of inferior trunk) Posterior cord (posterior divisions of all trunks - superior, middle, inferior)

Question 45

What are the 5 terminal branches of the brachial plexus?

Answer 45

Musculocutaneous (C5-C7) Axillary (C5, C6) Radial (C5-T1) Median (C6-T1) Ulnar (C8, T1)