Test 2 Posterior Forearm Muscles

Question 0

Brachioradialis proximal attachment , origin

Answer 0

proximal 2/3 of lateral supraepicondylar ridge of humerus

Question 1

superficial layer

Answer 1

• Brachioradialis
• Extensor carpi radialis longus
• extensor carpi radialis brevis
• extensor digitorum
• extensor digiti minimi
• extensor carpi ulnaris

Question 2

Brachioradialis distal attachment insertion

Answer 2

lateral surface of distal end of radius proximal to styloid process

Question 3

Brachioradialis innervation

Answer 3

radial nerve C5 C6 C7

Question 4

Brachioradialis action

Answer 4

weak flexion of forearm, maximal when forearm is in mid pronated position

Question 5

extensor carpi radialis longus proximal attchment origin

Answer 5

lateral supra epicondylar ridge of the humerus

Question 6

extensor carpi radialis longus distal attachment insertion

Answer 6

dorsal aspect of base of 2nd metacarpal

Question 7

extensor carpi radialis longus innervation

Answer 7

radial nerve C6 C7

Question 8

extensor carpi radialis longus action

Answer 8

-extend and abduct hand at wrist joint

Question 9

extensor carpi radialis brevis proximal attachment origin

Answer 9

lateral epicondyle of the humerus

Question 10

extensor carpi radialis brevis distal attachment insertion

Answer 10

dorsal aspect of base of 3rd metacarpal

Question 11

extensor carpi radialis brevis innervation

Answer 11

deep branch of radial nerve C7 C8

Question 12

extensor carpi radialis brevis action

Answer 12

• extends and abducts hand at wrist

- active during fist clenching

Question 13

extensor digitorum proximal attachment origin

Answer 13

lateral epicondyle of humerus

Question 14

extensor digitorum distal attachment insertion

Answer 14

extensor expansion of medial four fingers

Question 15

extensor digitorum innervation

Answer 15

posterior interosseous nerve C7 C8 = continuation of deep radial nerve

Question 16

extensor digitorum action

Answer 16

• extends medial four fingers primarily at metacrpophalangeal joints
• secondarily at interphalangeal joints

Question 17

extensor digiti minimi proximal attachment origin

Answer 17

lateral epicondyle of humerus

Question 18

extensor digiti minimi distal attachment insertion

Answer 18

extensor expansion of 5th finger

Question 19

extensor digiti minimi innervation

Answer 19

posterior interosseous nerve C7 C8 = continuation of deep branch of radial nerve

Question 20

extensor digiti minimi action

Answer 20

• extends fifth finger primarily at metacarpophalangeal joint
• secondarily at interphalangeal joint

Question 21

extensor carpi ulnaris proximal attachment origin

Answer 21

• lateral epicondyle of humerus

- posterior border of ulna via a shared aponeurosis

Question 22

extensor carpi ulnaris distal attachment insertion

Answer 22

dorsal aspect of the base of the 5th metacarpal

Question 23

extensor carpi ulnaris innervation

Answer 23

posterior interosseous nerve C7 C8 =continuation of deep branch of radial nerve

Question 24

extensor carpi ulnaris action

Answer 24

• extends and adducts hand at wrist joint

- also active during fist clenching

Question 25

deep layer of posterior forearm muscles

Answer 25

supinator

Question 26

supinator proximal attachment origin

Answer 26

• lateral epicondyle of humerus
• radial collateral and annular ligaments
• supinator fossa
• crest of ulna

Question 27

supinator distal attachment insertion

Answer 27

lateral posterior and anterior surfaces of proximal 1/3 of radius

Question 28

supinator innervation

Answer 28

deep branch of radial nerve C7 C8

Question 29

supinator action

Answer 29

• supinates forearm

- rotates radius to turn palm anteriorly or superiorly (if elbow is flexed)

Question 30

“outcropping” muscles of deep layer

posterior forearm

Answer 30

• abductor pollicis longus
• extensor pollicis longus
• extensor pollicis brevis
• extensor indicis

Question 31

abductor pollicis longus proximal attachment origin

Answer 31

posterior surface of proximal halves of ulna, radius, and interosseous membrane

Question 32

abductor pollicis longus distal attachment insertion

Answer 32

base of 1st metacarpal

Question 33

abductor pollicis longus innervation

Answer 33

posterior interoseous nerv C7 C8 = continuation of deep branch of radial nerve

Question 34

abductor pollicis longus action

Answer 34

• abducts thumb

- extends thumb at the carpometacarpal joint

Question 35

extensor pollicis longus proximal attachment origin

Answer 35

posterior surface of middle 1/3 of ulna and interosseous membrane

Question 36

extensor pollicis longus distal attachment insertion

Answer 36

dorsal aspect of base of distal phalanx of thumb

Question 37

extensor pollicis longus innervation

Answer 37

posterior interosseous nerve C7 C8 = continuation of deep branch of radial nerve

Question 38

extensor pollicis longus action

Answer 38

• extends distal phalanx of thumb at interphalangeal joint

- extends metacarpophalangeal and carpometacarpal joints

Question 39

extensor pollicis brevis proximal attachment origin

Answer 39

posterior surface of distal 1/3 of radius and interosseous membrane

Question 40

extensor pollicis brevis distal attachment insertion

Answer 40

dorsal aspect of base of proximal phalanx of thumb

Question 41

extensor pollicis brevis innervation

Answer 41

posterior interosseous nerve C7 C8 = continuation of the deep branch of radial nerve

Question 42

extensor pollicis brevis action

Answer 42

• extends proximal phalanx of thumb at metacarpophalangeal joint
• extends carpometacarpal joint

Question 43

extensor indicis proximal attachment origin

Answer 43

-posterior surface of distal 1/3 of ulna and interosseous membrane

Question 44

extensor indicis distal attachment insertion

Answer 44

extensor expansion of 2nd finger

Question 45

extensor indicis innervation

Answer 45

posterior interoseous nerve C7 C8 = continuation of deep branch of radial nerve

Question 46

extensor indicis action

Answer 46

• extends 2nd finger (enabling its independent extension)

- helps extend hand at wrist