Muscular System Pt. 7 - Muscles of the Posterior Forearm

Question 1

How many groups of muscles make up the posterior forearm muscles?

Answer 1

Two: Superficial and Deep

Question 2

How many muscles are in each group of posterior forearm muscles?

Answer 2

Superficial = 4
Deep = 5

Question 3

What are the names of the superficial muscles of the posterior forearm

Answer 3

Extensor carpi radialis longus, Extensor carpi ulnaris, Extensor digitorium, Extensor carpi radialis brevis

Question 4

Origin of all superficial posterior forearm muscles?

Answer 4

Lateral epicondyle of humerus (CEO - Common extensor origin)

Question 5

Insertion of extensor digitorium?

Answer 5

Distal phalanx of digits 2-5

Splits into 4 tendons that run down the 4 digits

Question 6

Insertion of Extensor carpi ulnaris?

Answer 6

Metacarpals

Closer to the ulnar side for insertion

Question 7

Insertion of Extensor carpi radialis longus

Answer 7

Metacarpals

ECRL means that it extends the wrist and its long and on the radial side

Question 8

Insertion of Extensor carpi radialis brevis

Answer 8

Metacarpals

ECRB means it extends the wrist and its short and on the radial side

Question 9

Actions that all the superficial posterior forearm muscles do?

Answer 9

Extension of wrist and elbow

All synergists to tricep brachii

Question 10

Action specific only to Extensor digitorium

Answer 10

Finger extension (2-5)

Question 11

Which muscle in the deep posterior forearm muscle is not grouped with the others?

Answer 11

Supinator muscle

Question 12

Origin of Supinator

Answer 12

Common Extensor Origin (Lateral epi. of humerus) and Ulna

Question 13

Insertion of Supinator

Answer 13

Radius

Question 14

Actions of Supinator

Answer 14

Forearm Supination

Question 15

What are the four muscles that are grouped together?

Answer 15

Abductor pollicis longus, Extensor Pollicis longus, Extensor indicis, Extensor pollicis brevis

Indicus is the only one with a different insertion

Question 16

Origin of the APL, EPL, EI and EPB

Answer 16

Radius, Ulna, and Interosseous membrane

Question 17

Insertion of Extensor Indicus

Answer 17

Distal phalanx of digit 2

Question 18

Insertion of APL, EPL, EPB

Answer 18

Thumb and first metacarpal

Question 19

Actions of the four grouped together (APL, EPL, EPB, EI)

Answer 19

Wrist extension, Finger/thumb extension

Question 20

Action specific to APL

Answer 20

Thumb aduction

Question 21

Action specific to Supinator

Answer 21

Forearm supination