Muscles (Posterior Forearm)

Question 1

Extensor muscles

Answer 1

• pass under an extensor retinaculum
• tendons pass through synovial tubes through wrist area
• muscles are layered, superficial and deep

Question 2

Superficial Extensors

Answer 2

• Extensor carpi radialis longus
• Extensor carpi radialis brevis
• Extensor digitorum communis
• Extensor Carpi ulnaris

Question 3

Deep Extensors

Answer 3

• Abductor pollicis longus
• Extensor pollicis longus
• Extensor polliis brevis
• Extensor indicis

Question 4

Intrinsic muscles of the hand

Answer 4

• Thenar muscle group
• Hypothenar muscle group
• Interossei muscles (7)
• Lumbricals

Question 5

Extensor carpi radialis longus

Answer 5

-Superficial extensor muscle
O. Above the lateral epicondyle of the humerus; just below origin of brachioradialis muscle
I. Base of 2nd metacarpal
A. Wrist extension; wrist abduction; elbow extension

Question 6

Extensor carpi radialis brevis

Answer 6

-Superficial extensor muscle
O. Lateral epicondyle of the humerus
I. Base of the 3rd metacarpal
A. Wrist extension; wrist abduction; elbow extension

Question 7

Extensor digitorum communis

Answer 7

-Superficial extensor muscle
O. Lateral epicondyle of the humerus
I. Dorsal expansion of the medial four digits
A. Wrist extension; metacarpal-phalangeal and interphalangeal extension; elbow extension

-a small slip of the extensor digitorum sends a second tendon to the little finger termed extensor digiti minimi; I. dorsal expansion of little finger

Question 8

Extensor Carpi ulnaris

Answer 8

-Superficial extensor muscle
O. Lateral epicondyle of the humerus
I. Base of 5th metacarpal
A. Wrist extension; wrist adduction; elbow extension

Question 9

Abductor pollicis longus

Answer 9

-Deep extensor muscle
O. proximal dorsal surface of the radius and ulna and interosseus membrane
I. Metacarpal of the thumb
A. Extends wrist and abducts thumb

Question 10

Extensor pollicis longus

Answer 10

-Deep extensor muscle
O. Posterior surface of the ulna and interosseus membrane
I. Distal phalanx of the thumb
A. Extends metacarpal/phalangeal and interphalangeal joints of the thumb, wrist ext.

Question 11

Extensor polliis brevis

Answer 11

-Deep extensor muscle
O. Posterior surface of the radius and interosseus membrane
I. Proximal phalanx of the thumb
A. Extends the metacarpal-phalangeal joint of thumb; wrist extension

Question 12

Extensor indicis

Answer 12

-Deep extensor muscle
O. Posterior surface of the ulna and interosseus membrane
I. Dorsal expansion on index finger
A. Extension of index finger, wrist extension

Question 13

Thenar muscle group

Answer 13

• Intrinsic muscle of the hand
• group of 3 muscles at base of thumb
• important in allowing thumb to oppose other digits and supplement flexion/abduction of thumb

Question 14

Hypothenar muscle group

Answer 14

• Intrinsic muscle of the hand
• group of 3 muscles at base of little finger
• contributes to movement

Question 15

Interossei muscles (7)

Answer 15

-Intrinsic muscle of the hand
O. series of 7 muscles originating from shafts of metacarpals
I. Dorsal expansion of four medial digits
A. As a group they are responsible for the adduction and abduction of the digits

Question 16

Lumbricals

Answer 16

-Intrinsic muscle of the hand
O. Series of 4 muscles originating from tedon of flexor digitorum profundus
I. Dorsal expansion of medial 4 digits
A. Flexion of the metacarpal/phalangeal joint and extension of the interphalangeal joint