Muscles of the Upper Limb

Question 1

What are the compartments of the arm, and what muscles are found in each?

Answer 1

The anterior compartment of the arm contains the biceps brachii, brachialis, and coracobrachialis, while the posterior compartment contains the triceps brachii.

Question 2

What is the innervation of the muscles in the anterior compartment of the arm?

Answer 2

The anterior compartment of the arm is innervated by the musculocutaneous nerve.

Question 3

What is the innervation of the muscles in the posterior compartment of the arm?

Answer 3

The posterior compartment of the arm is innervated by the radial nerve.

Question 4

What are the compartments of the forearm, and what muscles are found in each?

Answer 4

The forearm has an anterior compartment (flexors) and a posterior compartment (extensors).

Question 5

What is the innervation of the anterior compartment of the forearm?

Answer 5

The anterior compartment of the forearm is innervated by the median and ulnar nerves.

Question 6

What is the innervation of the posterior compartment of the forearm?

Answer 6

The posterior compartment of the forearm is innervated by the radial nerve.

Question 7

What muscles make up the rotator cuff?

Answer 7

The rotator cuff muscles are the supraspinatus, infraspinatus, teres minor, and subscapularis.

Question 8

What is the function of the rotator cuff muscles?

Answer 8

The rotator cuff muscles stabilize the shoulder joint and allow controlled movement.

Question 9

What nerve supplies the supraspinatus and infraspinatus muscles?

Answer 9

The supraspinatus and infraspinatus muscles are innervated by the suprascapular nerve.

Question 10

What nerve supplies the teres minor muscle?

Answer 10

The teres minor is innervated by the axillary nerve.

Question 11

What nerve supplies the subscapularis muscle?

Answer 11

The subscapularis is innervated by the upper and lower subscapular nerves.

Question 12

What are the actions of the deltoid muscle?

Answer 12

The deltoid muscle abducts, flexes, extends, and rotates the shoulder.

Question 13

What nerve supplies the deltoid muscle?

Answer 13

The deltoid is innervated by the axillary nerve.

Question 14

What are the main flexors of the elbow?

Answer 14

The main flexors of the elbow are the biceps brachii, brachialis, and brachioradialis.

Question 15

What are the main extensors of the elbow?

Answer 15

The main extensors of the elbow are the triceps brachii and anconeus.

Question 16

What is the function of the brachialis muscle?

Answer 16

The brachialis muscle is a strong flexor of the elbow joint.

Question 17

What are the actions of the biceps brachii?

Answer 17

The biceps brachii flexes the elbow and supinates the forearm.

Question 18

What is the function of the triceps brachii?

Answer 18

The triceps brachii extends the elbow joint.

Question 19

What nerve supplies the triceps brachii?

Answer 19

The triceps brachii is innervated by the radial nerve.

Question 20

What is the primary function of the coracobrachialis muscle?

Answer 20

The coracobrachialis flexes and adducts the shoulder joint.

Question 21

What is the action of the pronator teres muscle?

Answer 21

The pronator teres pronates the forearm and flexes the elbow.

Question 22

What is the action of the supinator muscle?

Answer 22

The supinator supinates the forearm.

Question 23

What are the primary wrist flexors?

Answer 23

The primary wrist flexors are the flexor carpi radialis, flexor carpi ulnaris, and palmaris longus.

Question 24

What are the primary wrist extensors?

Answer 24

The primary wrist extensors are the extensor carpi radialis longus, extensor carpi radialis brevis, and extensor carpi ulnaris.

Question 25

What is the action of the flexor carpi radialis?

Answer 25

The flexor carpi radialis flexes and abducts the wrist.

Question 26

What is the action of the flexor carpi ulnaris?

Answer 26

The flexor carpi ulnaris flexes and adducts the wrist.

Question 27

What is the function of the flexor digitorum superficialis?

Answer 27

The flexor digitorum superficialis flexes the proximal interphalangeal joints of the fingers.

Question 28

What is the function of the flexor digitorum profundus?

Answer 28

The flexor digitorum profundus flexes the distal interphalangeal joints of the fingers.

Question 29

What is the function of the extensor digitorum muscle?

Answer 29

The extensor digitorum extends the fingers at the metacarpophalangeal joints.

Question 30

What is the action of the extensor carpi ulnaris?

Answer 30

The extensor carpi ulnaris extends and adducts the wrist.

Question 31

What is the action of the extensor pollicis longus?

Answer 31

The extensor pollicis longus extends the thumb at the interphalangeal joint.

Question 32

What is the action of the extensor pollicis brevis?

Answer 32

The extensor pollicis brevis extends the thumb at the metacarpophalangeal joint.

Question 33

What is the function of the abductor pollicis longus?

Answer 33

The abductor pollicis longus abducts and extends the thumb.

Question 34

What muscles form the thenar eminence?

Answer 34

The thenar eminence consists of the abductor pollicis brevis, flexor pollicis brevis, and opponens pollicis.

Question 35

What muscles form the hypothenar eminence?

Answer 35

The hypothenar eminence consists of the abductor digiti minimi, flexor digiti minimi, and opponens digiti minimi.

Question 36

What is the function of the lumbricals?

Answer 36

The lumbricals flex the metacarpophalangeal joints and extend the interphalangeal joints.

Question 37

What is the function of the dorsal interossei?

Answer 37

The dorsal interossei abduct the fingers.

Question 38

What is the function of the palmar interossei?

Answer 38

The palmar interossei adduct the fingers.

Question 39

What is the innervation of the thenar muscles?

Answer 39

The thenar muscles are innervated by the median nerve.

Question 40

What is the innervation of the hypothenar muscles?

Answer 40

The hypothenar muscles are innervated by the ulnar nerve.

Question 41

What muscles are affected in carpal tunnel syndrome?

Answer 41

The thenar muscles are affected in carpal tunnel syndrome.

Question 42

What nerve is compressed in carpal tunnel syndrome?

Answer 42

The median nerve is compressed in carpal tunnel syndrome.

Question 43

What is the action of the palmaris longus muscle?

Answer 43

The palmaris longus flexes the wrist and tenses the palmar aponeurosis.

Question 44

What are the borders of the anatomical snuffbox?

Answer 44

The anatomical snuffbox is bordered by the extensor pollicis longus, extensor pollicis brevis, and abductor pollicis longus tendons.

Question 45

What is the clinical significance of the anatomical snuffbox?

Answer 45

The anatomical snuffbox is clinically significant because the radial artery passes through it, and scaphoid fractures can be palpated there.

Question 46

What is the function of the brachioradialis muscle?

Answer 46

The brachioradialis flexes the elbow, especially in a mid-pronated position.

Question 47

What nerve supplies the brachioradialis muscle?

Answer 47

The brachioradialis is innervated by the radial nerve.

Question 48

What muscles assist in ulnar deviation of the wrist?

Answer 48

The flexor carpi ulnaris and extensor carpi ulnaris assist in ulnar deviation.

Question 49

What muscles assist in radial deviation of the wrist?

Answer 49

The flexor carpi radialis and extensor carpi radialis longus assist in radial deviation.

Question 50

What muscles are responsible for finger abduction and adduction?

Answer 50

The dorsal interossei abduct the fingers, and the palmar interossei adduct them.