Posterior Forearm

Question 1

Superficial layer of the posterior compartment of the forearm

Answer 1

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

Question 2

Brachioradialis attachments

Answer 2

from… the lateral supracondylar ridge of the humerus
to… the distal radius lateral to the styloid process

Question 3

Brachioradialis actions

Answer 3

flexes the elbow

Question 4

Brachioradialis innervation

Answer 4

PNS: radial nerve
CNS: C5-6

Question 5

Extensor carpi radialis longus attachments

Answer 5

from… the lateral supracondylar ridge of the humerus
to… the base of the 2nd metacarpal

Question 6

Extensor carpi radialis longus actions

Answer 6

extends & abducts hand at wrist (radial deviation) & assists in flexion of the elbow

Question 7

Extensor carpi radialis longus innervations

Answer 7

PNS: radial nerve
CVS: C6-8

Question 8

Extensor carpi radialis brevis attachments

Answer 8

from… lateral epicondyle of the humerus (common extensor origin)
to… the base of the 3rd metacarpal

Question 9

Extensor carpi radialis brevis actions

Answer 9

extends & abducts hand at wrist (radial deviation)

Question 10

Extensor carpi radialis brevis innervation

Answer 10

PNS: radial nerve
CNS: C6-8

Question 11

Extensor digitorum attachments

Answer 11

from… the lateral epicondyle of the humerus (common extensor origin)
to… the extensor expansions of digits 2-5

Question 12

Extensor digitorum actions

Answer 12

extends phalanges (primarily at metacarpophalangeal, secondarily at interphalangeal) & extends hand at wrist

Question 13

Extensor digitorum innervations

Answer 13

PNS: radial nerve
CNS: C6-8

Question 14

Extensor digiti minimi attachments

Answer 14

from… the lateral epicondyle of the humerus (common extensor origin)
to… the digital expansion of the 5th digit

Question 15

Extensor digiti minimi actions

Answer 15

extends 5th digit (metacarpophalangeal & interphalangheal)

Question 16

Extensor digiti mini innervations

Answer 16

PNS: radial nerve
CNS: C7-8

Question 17

Extensor carpi ulnaris attachments

Answer 17

from… the lateral epicondyle of the humerus (common extensor origin)
to… the base of the 5th metacarpal

Question 18

Extensor carpi ulnaris actions

Answer 18

extends & adducts hand at wrist (ulnar deviation)

Question 19

Extensor carpi ulnaris innervations

Answer 19

PNS: radial nerve
CNS: C6-8

Question 20

Deep layer of the posterior compartment of the forearm

Answer 20

Supinator
Extensor indicis

Question 21

Supinator attachments

Answer 21

from… the lateral epicondyle of the humerus, radial collateral ligament & supinator crest of the ulna
to… the lateral surface of the proximal radius

Question 22

Supinator actions

Answer 22

supinates forearm

Question 23

Supinator innervations

Answer 23

PNS: radial nerve
CNS: C5-6

Question 24

Extensor indicis attachments

Answer 24

from… the posterior surface of the ulna & interosseous membrane
to… the digital expansion of the 2nd digit

Question 25

Extensor indicis actions

Answer 25

extends 2nd digit (metacarpophalangeal & interphalangeal

Question 26

Extensor indicis innervations

Answer 26

PNS: radial nerve CNS: C7-8

Question 27

Deep layer of the posterior compartment of the forearm (outcropping thumb muscles)

Answer 27

Abductor pollicis longus Extensor pollicis brevis Extensor pollicis longus

Question 28

Abductor pollicis longus attachments

Answer 28

from... proximal posterior radius, ulna & interosseous membrane to... the base of the 1st metacarpal & trapezium

Question 29

Abductor pollicis longus actions

Answer 29

abducts & extends thumb at carpometacarpal joint & abducts hand at wrist (radial deviation)

Question 30

Abductor pollicis longus innervation

Answer 30

PNS: radial nerve CNS: C6-8

Question 31

Extensor pollicis brevis attachments

Answer 31

from... the posterior radial surface & interosseous membrane to... the base of the 1st proximal phalanx

Question 32

Extensor pollicis brevis actions

Answer 32

extends thumb (metacarpophalangeal) & extends & abducts CMC joint

Question 33

Extensor pollicis brevis innervations

Answer 33

PNS: radial nerve CNS: C6-8

Question 34

Extensor pollicis longus attachments

Answer 34

from... the middle 1/3rd of the posterior surface of the ulna & interosseous membrane to... the base of the 1st distal phalanx

Question 35

Extensor pollicis longus actions

Answer 35

extends thumb (CMC & metacarpophalangeal & interphalangeal)

Question 36

Extensor pollicis longus innervations

Answer 36

PNS: radial nerve CNS: C6-8

Question 37

Radial nerve muscular branches

Answer 37

Brachioradialis Supinator Extensor carpi radialis longus Extensor carpi radialis brevis Extensor carpi ulnaris Extensor digitorum Extensor digiti minimi Extensor indicis Extensor pollicis brevis Extensor pollicis longus Abductor pollicis longus