Muscles of extensor forearm

Question 1

Muscles of extensor forearm

Answer 1

1. extensor carpi radialis longus
2. extensor carpi radialis brevis
3. extensor digitorum
4. extensor digiti minimi
5. extensor carpi ulnaris
6. abductor pollicis longus
7. extensor pollicis brevis
8. extensor pollicic longus
9. extensor indicis
10. supinator

Question 2

Superficial layer of extensor forearm

Answer 2

1. extensor carpi radialis longus
2. extensor carpi radialis brevis
3. extensor digitorum
4. extensor digiti minimi
5. extensor carpi ulnaris

Question 3

Extensor carpi radialis longus

Answer 3

O-lateral supraepicondylar ridge of humerus
I- dorsal surface, base of second metacarpal
A- extends and abducts the hand
N- radial nerve

Question 4

extensor carpi radialis brevis

Answer 4

O- lateral epicondyle
I-base of 3rd metacarpal; dorsal surface
A- extends and assists in abduction of the hand
N- radial nerve

Question 5

extensor digitorum

Answer 5

O- lateral epicondyle
I- distal phalanges 2-5; dorsal surface
A- extends digits 2-5 and assists in extension of the hand
N- radial nerve
Notes- has intertendinous connections

Question 6

intertendinous connects

Answer 6

-obliquely oriented connective tissue bands that unite tendons of extensor digitorum as they cross dorsum of hands

Question 7

extensor digiti minimi

Answer 7

O- lateral epicondyle of humerus
I- dorsal surface; proximal 5 digit
A- extend 5th digit
N- radial nerve

Question 8

extensor expansion or extensor hood

Answer 8

• spans dorsum of entire phalanges
• provides means of distributing force extorted by extensor digitum on MP and IP joints
• site of muscle attachment for 2 groups of muscles in hand, lumbricals and interossei

Question 9

extensor carpi ulnaris

Answer 9

O-lateral epicondlye of humerus and posterior border of ulna
I- base of 5th metacarpal
A- extend and adducts hand
N- radial nerve

Question 10

Abductor pollicis longus

Answer 10

O- posterior surface of ulna and radius
I- dorsolateral surface of base of 1st metacarpal
A- abducts thumb and wrist; assists in extension of thumb
N- radial nerve

Question 11

muscles of deep layer of extensor forearm

Answer 11

1. abductor pollicis longus
2. extensor pollicis brevis
3. extensor pollicis longus
4. extensor indicis
5. supinator

Question 12

extensor pollicis brevis

Answer 12

O- posterior surface of radius distal 1/3
I- base of proximal phalanx of thumb
A- extends proximal phalanx of thumb and 1st metacarpal
N- radial nerve

Question 13

extensor pollicis longus

Answer 13

O- posterior surface of ulna
I- base of distal phalanx; dorsal surface
A- extends thumb and IP and MP joints
N- radial nerve

Question 14

anatomical snuff box

Answer 14

• formed from tendons of abductor pollicis longs, extensor pollicis brevis, and extensor pollicis longus
• posterior- tendon of extensors pollicis longus
• anterior- extensos pollicis brevis and abductor pollicis longus
• floor- scaphiod bone
• near floor= radial artery
• roof- branches of superficial radial nerve

Question 15

extensor indicis

Answer 15

O- posterior surface of ulna
I- dosrum; base of distal phalanx of 2nd digit with extensor expansion
A- extends index finger
N- radial nerve

Question 16

supinator

Answer 16

O-lateral epicondyle of humerus; radial collateral ligament of elbow; annular ligament of radial head; supinator fossa of ulna and associated crest
I- lateral and anterior surface of proximal 3rd radius
A- supiantes the hand
N-radial nerve

Question 17

extensor retinaculum

Answer 17

• encloses all 9 of extensor muscles

- band of deep fascia