SDL Week 2: Pectoral Girdle and Shoulder

Question 1

Describe the shape of the clavicle

Answer 1

the lateral third is concave, but the medial two thirds are convex

Question 2

Where is the scapula found?

Answer 2

between the second and seventh ribs

Question 3

How is the dorsal surface of the scapula divided?

Answer 3

its divided into supraspinous and infraspinous fossae by the spine of the scapula
spine becomes continous with the acromion

Question 4

What happens to the scapula when you lift your arm above your head?

Answer 4

• the inferior angle is moved laterally and cranially

- the face of the glenoid cavity moves upwards

Question 5

For the trapezius, what are its:

1. Origins
2. Insertions
3. Innervation

Answer 5

1. Originates at the skull
2. Inserts on the clavicle, acromion and scapula spine
3. Innervation is the accessory nerve

Question 6

The trapezius consists of upper, middle and lower fibres. Which fibres is responsible for which movements of the scapula?

Answer 6

1. Upper fibres - elevation and rotation of scapula
2. Middle fibres - retraction of scapula
3. Lower fibres - pull the scapula inferiorly

Question 7

Where is the latissimus dorsi?

Answer 7

large, flat, triangular muscle that sweeps over the lumbar region and lower thorax

Question 8

For latissimus dorsi, what are its:

1. Origins
2. Actions
3. Innervation

Answer 8

1. Arises from the spinous processes of T6-12
2. Extends, adducts and medially rotates the upper limbs
3. Innervation by the thoracodorsal nerve

Question 9

Where does the narrow tendon of latissimus dorsi insert on the humerus?

Answer 9

intertubercular groove

Question 10

For levator scapulae, what are its:

1. Origins
2. Actions
3. Insertion

Answer 10

1. Originates at the transverse processes of C1-C4
2. Action is to elevate scapula
3. Insertion onto the medial border of the scapula

Question 11

For rhomboid major, what are its:

1. Origins
2. Insertion
3. Action

Answer 11

1. Originates at the spinous process of T2-T5
2. Inserts on the medial border if the scapula
3. Action is to retract and rotate the scapula

Question 12

For rhomboid minor, what are its:

1. Origins
2. Insertion
3. Action

Answer 12

1. Originates on the spinous processes of C7-T1 vertebrae
2. Inserts onto the medial border of the scapula
3. Action is to retract and rotate the scapula

Question 13

For pectoralis major, what are its:

1. Insertion
2. Action

Answer 13

1. Inserts on the intertubercular sulcus of the humerus

2. Action is to adduct and medially rotate the upper limb

Question 14

For serratus anterior, what are its:

1. Origins
2. Insertion
3. Action

Answer 14

1. Originates from the lateral aspects of ribs 1-8
2. Inserts on the costal surface of the medial border of the scapula
3. Rotates the scapula, allowing the arm to be raised over 90 degrees

Question 15

Where does the pectoralis minor originate, insert and what is its action?

Answer 15

Originates from ribs 2-5
Inserts on the coracoid process of the scapula
It stabilises the scapula and contributes to protraction

Question 16

What are the possible movements at the shoulder joint

Answer 16

Adduction
Abduction
Flexion
Extension
Internal rotation
External rotation
Circumduction

Question 17

What factors help maintain stability at the shoulder joint?

Answer 17

• tendon of the long head of biceps brachii
• glenoid labrum
• rotator cuff muscles
• ligaments
• biceps tendon

Question 18

What are the scapulohumeral muscles?

Answer 18

• rotator cuff muscles

- deltoid and teres major

Question 19

For the deltoid, what is the:

1. Origin
2. Insertion
3. Innervation

Answer 19

1. Lateral third of clavicle, acromion and spine of scapula
2. Inserts onto the deltoid tuberosity on lateral aspect of humerus
3. Innervated by the axillary nerve

Question 20

For deltoid, what is the action of the:

1. Anterior fibres
2. Middle fibres
3. Posterior fibres

Answer 20

1. Flexion and medial rotation
2. Major abductor of arm
3. Extension and lateral rotation

Question 21

For teres major, what are its:

1. Origins
2. Actions
3. Insertions
4. Innervation

Answer 21

1. Posterior surface of the inferior angle of the scapula
2. Inserts onto the intertubercular groove of the humerus
3. Innervation by the lower subscapular nerve
4. Adducts and extends at the shoulder, and medially rotates the arm

Question 22

Which rotator cuff muscle initiates abduction?

Answer 22

supraspinatus

Question 23

Which of the rotator cuff muscles is located on the anterior aspect of the scapula?

Answer 23

subscapularis

Question 24

For supraspinatus, what is its:

1. Origin
2. Insertion
3. Action

Answer 24

1. Supraspinous fossa of scapula
2. Greater tubercle of humerus
3. Abducts the arm 0-15o, and assists deltoid for 15-90o

Question 25

For infraspinatus, what is its:

1. Origin
2. Insertion
3. Action

Answer 25

1. infraspinous fossa of the scapula
2. greater tubercle of the humerus
3. laterally rotates the arm

Question 26

For teres minor, what is its:

1. Origin
2. Insertion
3. Action

Answer 26

1. posterior surface of scapula
2. greater tubercle
3. laterally rotates the arm

Question 27

For subscapularis, what is its:

1. Origin
2. Insertion
3. Action

Answer 27

1. Subscapula fossa
2. Lesser tubercle of humerus
3. Medially rotates arm