Wrist and hand - muscles (extensors of the wrist and digits)

Question 1

Name the 5 superficial extensor muscles and identify where they are located on the human body (if unable check on Complete Anatomy)

Answer 1

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

Question 2

What is the Function, Origin and Insertion of the Extensor carpi radialis longus muscle?

Answer 2

o Function – Wrist extension, radial deviation
o Origin – Lateral epicondyle
o Insertion – Base metacarpal II

Question 3

What is the Function, Origin and Insertion of the Extensor carpi radialis brevis muscle?

Answer 3

o Function – Wrist extension, radial deviation
o Origin – Lateral epicondyle
o Insertion – Base Metacarpal III

Question 4

What is the Function, Origin and Insertion of the Extensor digitorum muscle?

Answer 4

o Function – Extends fingers
o Origin – Lateral epicondyle
o Insertion – Dorsal digital expansion (Extensor hood)
 Fibrous extension of extensor digitorum tendons on back of fingers

Question 5

What is the Function, Origin and Insertion of the Extensor digiti minimi muscle?

Answer 5

o Function – Extends little finger
o Origin – Lateral epicondyle
o Insertion – Dorsal digital expansion

Question 6

What is the Function, Origin and Insertion of the Extensor carpi ulnaris muscle?

Answer 6

o Function – Wrist extension, ulnar deviation
o Origin – Lateral epicondyle
o Insertion – Base metacarpal V

Question 7

What is the common origin point for all superficial extensors?

Answer 7

Lateral epicondyle

Question 8

Name the 4 deep extensor muscles and identify where they are located on the human body (if unable check on Complete Anatomy)

Answer 8

Extensor Indicis
Extensor Pollicis Longus
Extensor Pollicis Brevis
Abductor Pollicis Longus

Question 9

What is the Function, Origin and Insertion of the Extensor indicis muscle?

Answer 9

o Function – Extends index finger
o Origin
o Insertion – Dorsal digital expansion

Question 10

What is the Function, Origin and Insertion of the Extensor pollicis longus muscle?

Answer 10

o Function – Extends thumb
o Origin
o Insertion – Distal Phalanx

Question 11

What is the Function, Origin and Insertion of the Extensor pollicis brevis muscle?

Answer 11

o Function – Extends thumb, not IP joint
o Origin
o Insertion – Proximal phalanx

Question 12

What is the Function, Origin and Insertion of the Abductor pollicis longus muscle?

Answer 12

o Function – Abducts thumb, Extends thumb, Only CMC joint
o Origin
o Insertion – Metacarpal I