Shoulder

Question 1

Supraspinatus

Answer 1

Origin - supraspinous fossa of scapula

Insertion - upper facet of greater tubercle of humerus

Action - initiates abduction

Question 2

Subscapularis

Answer 2

Origin - medial 2/3 of subscapular fossa

Insertion - lesser tubercle of humerus

Action - medial rotation, and assists adduction, of humerus

Question 3

Coracobrachialis

Answer 3

Origin - tip of the coracoid process

Insertion - medial aspect of the mid shaft of the humerus

Action - flexion and horizontal adduction of humerus

Question 4

Serratus anterior

Answer 4

Origin - external surfaces of the upper 8 (9 or 10) ribs and intercostal fascia

Insertion - costal surface of medial border of the scapula

Action - protraction of scapula

Question 5

Infraspinatus

Answer 5

Origin - medial 2/3 of infraspinous fossa of scapula

Insertion - middle facet of greater tubercle humerus

Action - lateral rotation of humerus

Question 6

Pectoralis minor

Answer 6

Origin - outer surface of the 3rd, 4th, and 5th ribs

Insertion - tip of coracoid process

Action - protraction and depression of scapula

Question 7

Teres major

Answer 7

Origin - inferior angle and the adjacent lateral boarder of the scapula

Insertion - medial lip of the intertubercular groove

Action - extension, adduction and medial rotation of the humerus

Question 8

Teres minor

Answer 8

Origin - upper 2/3 of lateral border of the scapula

Insertion - lower facet of greater tubercle of humerus

Action - lateral rotation and adduction of humerus

Question 9

Rhomboids

Answer 9

Origin - spinous processes and intervening supraspinous ligaments of T2 to T5

Insertion - medial border of the scapula between base of spine and inferior angle

Action - medial rotation and retraction of the scapula

Question 10

Pectoralis major

Answer 10

Origin - clavicular head of medial half of anterior surface of the clavicle. Sternal head arises from anterior surface of manubrium, sternum, upper 6 costal cartilages and anterior aspect of rectus sheath

Insertion - lateral lip of the intertubercular groove

Action - flexion, horizontal adduction and internal rotation of humerus

Question 11

Deltoid

Answer 11

Origin - anterior border of lateral third of clavicle, the lateral border of acromion and the lower lip of scapular spine
Insertion - deltoid tuberosity, ½ way down the lateral aspect of the shaft of humerus
Action - abduction of humerus, also anterior fibres aid flexion and posterior fibres aid extension

Question 12

Latissimus dorsi

Answer 12

Origin - clavicular head of medial half of anterior surface of the clavicle. Sternal head arises from anterior surface of manubrium, sternum, upper 6 costal cartilages and anterior aspect of rectus sheath

Insertion - lateral lip of the intertubercular groove

Action - flexion, horizontal adduction and internal rotation of humerus

Question 13

Trapezius

Answer 13

Origin - medial 1/3 of superior nuchal line, the ligamentum nuchae and the tips of the spinous processes and intervening supraspinous ligaments from C7 to T12

Insertion - superior fibres attach to posterior border of the lateral 1/3 of clavicle; the middle fibres pass horizontally to attach to the crest of the scapular spine; the inferior fibres attach to a tubercle at its lateral apex

Action - retraction, elevation and depression of scapula, also cervical extension and side flexion

Question 14

Triceps brachii

Answer 14

Origin - long head: infraglenoid tubercle of the scapula, medial head: posterior surface of the humerus, Lateral head: lateral border of the humerus
Insertion - upper surface of olecranon process of the ulna
Action - elbow extension and long head assists extension of humerus at the shoulder

Question 15

Biceps brachii

Answer 15

Origin - short head: tip of coracoid process, long head: supraglenoid tubercle

Insertion - posterior aspect of the radial tuberosity

Action - forearm flexion and supination, long head assists shoulder flexion