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Flashcards in Posterior Forearm Deck (33):
1

how many muscles are there in the superficial layer of the posterior compartment of the forearm?

6 (in sheffield, 7 in leicester - anconeus)

2

which nerve innervates all muscles in the posterior forearm?

radial nerve

3

what is the general action of the posterior compartment of the forearm?

extension

4

where is the common extensor origin?

lateral epicondyle of the humerus

5

which 4 muscles come off the common extensor origin?

extensor carpi radialis brevis
extensor digitorum
extensor carpi ulnaris
extensor digiti minimi

6

what are the attachments of the brachioradialis?

humerus
distal radius

7

what is the action of brachioradialis?

FLEXOR at elbow

8

which aspect of the forearm do the ECRL and ECRB muscles run down? what action does this enable them to produce?

lateral aspect - abduction at wrist

9

what is the action of extensor carpi radialis longus?

abduction and extension at wrist

10

what is the action of extensor carpi radialis brevis?

abduction and extension at wrist

11

which muscle is the main extensor of fingers (at MCP and IP!)

extensor digitorum

12

what is the action of extensor digitorum?

extension of fingers at MCP and IP joints

13

what are the attachments of extensor digitorum?

lateral epicondyle
extensor hood of each finger

14

what are the attachments of extensor digiti minimi?

lateral epicondyle
extensor hood of little finger

15

what is the action of extensor digiti minimi?

extends little finger
contributes to wrist extension

16

along which aspect of forearm does extensor carpi ulnaris lie? what action does this position enable it to produce?

medial aspect
adduction at wrist

17

what is the action of extensor carpi ulnaris?

adduction and extension at wrist

18

name the 6 muscles of the superficial layer of the posterior compartment of the forearm?

brachioradialis
extensor carpi radialis longus + brevis
extensor digitorum
extensor digiti minimi
extensor carpi ulnaris

(bonus for leicester: anconeus)

19

how many muscles are there in the deep layer of the posterior compartment of the forearm?

5

20

how many muscles are there in the posterior forearm?

11 - 5 in deep, 6 in superficial

21

which digits do most of the deep muscles of the posterior compartment of the forearm act upon?

thumb and index finger (all but supinator)

22

where in the cubital fossa does the supinator lie?

the floor

23

what structure passes between the two heads of the supinator?

deep branch of radial nerve

24

what are the attachments of the supinator?

two heads: lateral epicondyle / posterior surface of ulna
attach to posterior surface of radius

25

to which border of the anatomical snuffbox does the abductor pollicis longus tendon contribute?

lateral

26

which tendons contribute to the lateral border of the anatomical snuffbox?

abductor pollicis longus and extensor pollicis brevis

27

what is the action of abductor pollicis longus

abducts thumb

28

to which border of the anatomical snuffbox does the extensor pollicis brevis tendon contribute?

lateral

29

what is the action of the extensor pollicis brevis?

extends thumb at MCP + carpometacarpal joints of thumb

30

to which border of the anatomical snuffbox does the extensor pollicis longus tendon contribute?

medial

31

what is the action of the extensor pollicis longus?

extends all thumb joints - carpometacarpal, MCP and IP

32

what is the action of extensor indicis?

extends index finger - allows independent movement of index finger when extended

33

name the 5 muscles of the deep layer of the posterior compartment of the forearm

supinator
abductor pollicis longus
extensor pollicis brevis
extensor pollicis longus
extensor indicis