LECTURE 3: UPPER EXTREMITY MUSCLE COMPARTMENTS

Question 1

What is the action of the coracobrachialis?

Answer 1

Flexor of the arm (shoulder; crosses shoulder joint)

Question 2

What is the action of the brachialis?

Answer 2

Flexor (when load is required) and supinator (when elbow is in flex position such unscrewing a cap) of the forearm

Question 3

What is the innervation to the anterior compartment of the arm?

Answer 3

Musculocutaneous nerve

Question 4

What is the action of the triceps brachii?

Answer 4

extension of forearm (elbow)

Question 5

What is housed in the quadrangular space?

Answer 5

has axillary nerve that innervated deltoid and teres minor traveling through

Question 6

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

Answer 6

radial nerve

Question 7

What forms the borders of the cubital fossa?

Answer 7

• Brachioradialis muscle
• Pronator teres muscle
• Epicondyles of humerus

Question 8

What covers the cubital fossa?

Answer 8

bicipital aponeurosis

Question 9

What is the medial cubital vein?

Answer 9

The median cubital vein (used to draw blood) travels over the aponeurosis and connects the cephalic and basilic veins

Question 10

What is the path of the radial and ulnar nerve?

Answer 10

• Radial nerve passes under the brachioradialis

* Ulnar nerve passes posterior to the medial epicondyle

Question 11

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

Answer 11

median nerve (with the exception of flexor carpi ulnaris which is innervated by ulnar nerve)

Question 12

What is the insertion and action of the flexor digitorum superficialis?

Answer 12

• Inserts in Medial humerus and radius to middle phalanges of digits 2-5
• Flexes digits at metacarpal-phalangeal joint and PIP

Question 13

What is the insertion and action of the flexor carpi ulnaris?

Answer 13

Inserts onto the medial carpals and flexes and adducts the wrist

Question 14

What is the insertion and action of the palmaris longus?

Answer 14

Attaches to palmar aponeurosis of hand and flexes wrist, may be absent in some

Question 15

What is the palmar aponeurosis?

Answer 15

a triangular deep fascia over the palm, extending to the digits

Question 16

What is the insertion and action of the flexor carpi radialis?

Answer 16

Inserts onto the lateral metacarpals and thus flexes and abducts wrist

Question 17

What is the insertion and action of the pronator teres?

Answer 17

Attaches to radius and pronates forearm

Question 18

What is the insertion and action of the flexor digitorum profundus?

Answer 18

Insert on distal phalanges of digits 2-5 and flex DIP (can also flex at PIP, MCP and wrist joint)

Question 19

What is the innervation of the flexor digitorum profundus?

Answer 19

Innervated by both the ulnar and median nerve

Question 20

What is the insertion and action of the flexor pollcis longus?

Answer 20

Inserts on phalanx of thumb and flexes the interphalangeal joint and MCP

Question 21

What is the insertion and action of the flexor protnator quadratus?

Answer 21

• Quadrangular muscle from distal ulna (origin) to radius (insertion)
• Pronation of forearm

Question 22

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

Answer 22

radial nerve

Question 23

What is the role of the extensor carpi radialis longus and brevis?

Answer 23

extensors and abductors of the wrist

Question 24

What is the role of the extensor carpi ulnaris?

Answer 24

Runs from lateral humerus to medial metacarpals and is a wrist extensor and adductor

Question 25

What is the role of the extensor digitorum and digit minimi?

Answer 25

Extensors of digits 2-5 and 5, respectively

Question 26

What is the action of the anconeus?

Answer 26

Small triangular muscle posterior to elbow joint, accessory extensor

Question 27

What is the action of the brachioradialis?

Answer 27

Crosses over lateral elbow joint and is an accessory flexor of the elbow

Question 28

What is the action of the abductor pollicis longus?

Answer 28

Attaches to lateral metacarpal (of the thumb) to abduct thumb

Question 29

What is the insertion and action of the abductor extensor pollicis longus and brevis?

Answer 29

Insert on distal and proximal phalanx of thumb, Extend joints of the thumb

Question 30

What is the insertion and action of the abductor extensor indicis?

Answer 30

Inserts on digit 2 (pointer) to extend that digit

Question 31

What is the insertion and action of the supinator?

Answer 31

Wraps around lateral side of elbow to supinate the forearm

Question 32

How is carpal tunnel formed?

Answer 32

Formed by arch of the carpal bones and the overlaying flexor retinaculum (sheet between the carpel bones forming carpal tunnel)

Question 33

What are the contents of the carpal tunnel?

Answer 33

* Tendons of flexor digitorum profundus * Tendons of flexor digitorum superficialis * Tendon of flexor pollicis longus * Median nerve

Question 34

What is carpal tunnel syndrome?

Answer 34

Median nerve gets compressed

Question 35

What is the anatomical snuffbox?

Answer 35

dip in hand

Question 36

What is the contents of the snuffbox?

Answer 36

* Radial artery | * Scaphoid and trapezium bones form floor (lateral from the first row)

Question 37

What is the boundary of the snuffbox?

Answer 37

Extensor pollicis longus and brevis tendons

Question 38

What are the extrinsic muscles of the hand?

Answer 38

Muscles that move the hand (power grip), but muscle bellies lie in the forearm and tendons extend to the hand

Question 39

What is the innervation of the extrinsic muscles of the hand?

Answer 39

median, ulnar, and radial nerves

Question 40

What is the innervation of intrinsic muscles of the hand?

Answer 40

ulnar and median nerves

Question 41

What are the intrinsic muscles of the hand?

Answer 41

Palmaris brevis, palmar and dorsal interossei, adductor pollicis, thenar and hypothenar groups, and lumbricals

Question 42

What is the palmaris brevis?

Answer 42

* Small quadrangular muscle over the hypothenar eminence | * Improves grip

Question 43

What is the adductor pollicis?

Answer 43

* Triangular muscle that attaches to proximal phalanx of thumb * Adducts thumb

Question 44

What are interossei muscles?

Answer 44

Interossei muscles run between the metacarpals

Question 45

What is the action of dorsal interossei?

Answer 45

Abduction of digits 2-4 | "DABB" 4 muscles

Question 46

What is the action of palmar interossei?

Answer 46

* 3 muscles * Adduction of digits 2,4,5 * “PAD”

Question 47

What is action of the lumbcricals?

Answer 47

* 4 muscles that extend from tendons of flexor digitorum profundus and attach to tissue on phalanges * Flex MCP joint and extend PIP and DIP joint

Question 48

What is the action of the oppenens pollicis?

Answer 48

Opposition of thumb

Question 49

What are muscles of the thenar group?

Answer 49

opponens pollicis, flexor pollicis brevis, abductor pollicis brevis

Question 50

What is the action of the flexor pollicis brevis?

Answer 50

Flexes thumb at MCP joint

Question 51

What is the action of the abductor pollicis brevis?

Answer 51

Abducts thumb at MCP joint

Question 52

What are the muscle of the hypothenar group?

Answer 52

opponens digiti minimi, flexor digiti minimi brevis, abductor digiti brevis

Question 53

What is the action of the abductor digiti brevis?

Answer 53

Abductor of digit 5

Question 54

What is the action of the flexor digiti brevis?

Answer 54

Flexes digit 5 at MCP joint

Question 55

What is the action of the opponens digiti brevis?

Answer 55

Opposition of digit 5

Question 56

How are the superficial and deep palmar arches formed?

Answer 56

Radial and ulnar arteries enter the hand and form two interconnected arterial arches

Question 57

What are the pulse points in the arm?

Answer 57

* Axillary * Brachial (medial to biceps tendon) * Radial * Ulnar

Question 58

What is Allen's Test?

Answer 58

for adequate contribution of both arteries (radial and ulnar) to the hand