Muscles Of The Upper Extremities

Question 1

Which four muscles make up the rotator cuff?

Answer 1

Supraspinatus, Infraspinatus, Teres Minor, Subscapularis

Question 2

What is the primary function of the supraspinatus muscle?

Answer 2

Initiates shoulder abduction (first 15 degrees)

Question 3

Which rotator cuff muscle is responsible for external rotation of the shoulder?

Answer 3

Infraspinatus and Teres Minor

Question 4

What is the insertion of the subscapularis muscle?

Answer 4

Lesser tubercle of the humerus

Question 5

Which nerve innervates the deltoid muscle?

Answer 5

Axillary nerve (C5-C6)

Question 6

What is the primary function of the serratus anterior?

Answer 6

Protraction and upward rotation of the scapula

Question 7

What injury is associated with long thoracic nerve damage?

Answer 7

Winged scapula (Serratus anterior dysfunction)

Question 8

Which muscle is the main flexor of the elbow?

Answer 8

Brachialis

Question 9

What is the difference between the actions of the biceps brachii and brachialis?

Answer 9

Biceps brachii flexes the elbow and supinates the forearm; brachialis is a pure elbow flexor

Question 10

What is the insertion of the biceps brachii?

Answer 10

Radial tuberosity

Question 11

Which nerve innervates the triceps brachii?

Answer 11

Radial nerve (C6-C8)

Question 12

What is the primary function of the triceps brachii?

Answer 12

Elbow extension

Question 13

Which muscle is responsible for forearm supination?

Answer 13

Supinator (primary), Biceps brachii (secondary)

Question 14

Which muscles are responsible for wrist flexion?

Answer 14

Flexor carpi radialis, Flexor carpi ulnaris, Palmaris longus

Question 15

What is the innervation of the flexor carpi ulnaris?

Answer 15

Ulnar nerve (C8-T1)

Question 16

Which muscles are responsible for wrist extension?

Answer 16

Extensor carpi radialis longus, Extensor carpi radialis brevis, Extensor carpi ulnaris

Question 17

What is the primary function of the flexor digitorum superficialis?

Answer 17

Flexes the PIP joints of fingers 2-5

Question 18

What is the primary function of the flexor digitorum profundus?

Answer 18

Flexes the DIP joints of fingers 2-5

Question 19

What is the innervation of the flexor digitorum profundus?

Answer 19

Median nerve (lateral half) and Ulnar nerve (medial half)

Question 20

Which muscle is the primary abductor of the thumb?

Answer 20

Abductor pollicis longus

Question 21

What muscles make up the thenar eminence?

Answer 21

Abductor pollicis brevis, Flexor pollicis brevis, Opponens pollicis

Question 22

What is the function of the opponens pollicis muscle?

Answer 22

Thumb opposition (touching thumb to pinky)

Question 23

Which muscles make up the hypothenar eminence?

Answer 23

Abductor digiti minimi, Flexor digiti minimi, Opponens digiti minimi

Question 24

What is the function of the lumbricals?

Answer 24

Flex MCP joints and extend PIP/DIP joints of fingers

Question 25

What is the function of the dorsal interossei?

Answer 25

Finger abduction (DAB: Dorsal ABducts)

Question 26

What is the function of the palmar interossei?

Answer 26

Finger adduction (PAD: Palmar ADducts)

Question 27

Which nerve innervates the majority of the intrinsic hand muscles?

Answer 27

Ulnar nerve (except thenar muscles and lateral two lumbricals, which are median nerve)

Question 28

What is the clinical significance of the median nerve in the wrist?

Answer 28

Compression leads to carpal tunnel syndrome

Question 29

Which muscle is affected in tennis elbow (lateral epicondylitis)?

Answer 29

Extensor carpi radialis brevis

Question 30

Which muscle is affected in golfer's elbow (medial epicondylitis)?

Answer 30

Flexor carpi radialis and pronator teres