Thumb & Hand

Question 1

Abductor Pollicis Longus

Answer 1

O: posterior surface of radius and ulna and interosseous membrane

I: base of first metacarpal

A: abduct thumb, extend thumb abduct wrist

N: radial C6, 7, 8

Question 2

Extensor Pollicis Longus

Answer 2

O: posterior surface of ulna and interosseous membrane

I: base of distal phalanx of thumb

A: extend thumb, abduct wrist

N: radial C6, 7, 8

Question 3

Extensor Pollicis Brevis

Answer 3

O: posterior surface of radius and interosseous membrane

I: base of proximal phalanx of thumb

A: extend thumb, abduct wrist

N: radial C6, 7, 8

Question 4

Flexor Pollicis Longus

Answer 4

O: anterior surface of radius and interosseous membrane

I: base of distal phalanx of thumb

A: flex thumb, assist flex wrist

N: median C(6), 7, 8, T1

Question 5

Abductor Pollicis Brevis

Answer 5

O: flexor retinaculum, trapezium and scaphoid tubercles

I: base of proximal phalanx of thumb

A: abduct thumb, assist opposition of thumb

N: median C6, 7, 8, T1

Question 6

Flexor Pollicis Brevis

Answer 6

O: superficial head: flexor retinaculum
deep head: trapezium, trapezoid, capitate

I: base of proximal phalanx of thumb

A: flex thumb, assist opposition of thumb

N: superficial head: median C6, 7, 8, T1
deep head: ulnar C8, T1

Question 7

Opponens Pollicis

Answer 7

O: flexor retinaculum, tubercle of trapezium

I: entire length of first metacarpal bone, radial surface

A: opposition of thumb

N: median C6, 7, 8, T1

Question 8

Adductor Pollicis

Answer 8

O: capitate, second and third metacarpals

I: base of proximal phalanx of thumb

A: adduct thumb, assist flex thumb

N: ulnar C8, T1

Question 9

Lumbricals of Hand

Answer 9

O: surfaces of flexor digitorum profundus tendons

I: extensor aponeurosis on dorsal surface of phalanges

A: extend second through fifth fingers at IP joints, flex second through fifth fingers at MCP joints

N: second and third fingers: median C(6), 7, 8, T1
fourth and fifth fingers: ulnar C(7), 8, T1

Question 10

Palmar Interossei

Answer 10

O: base of first, second, fourth, fifth metacarpals

I: base of proximal phalanx of related finger and entensor aponeurosis

A: adduct thumb, second, fourth, fifth fingers towards third finger, assist flex thumb, second, fourth, fifth fingers at MCP joints, assist extend thumb, second, fourth, fifth fingers at IP joints

N: ulnar C8, T1

Question 11

Dorsal Interossei

Answer 11

O: adjacent sides of all metacarpals

I: base of proximal phalanx of second, third, fourth fingers, extensor aponeurosis

A: abduct second, third, fourth fingers at MCP joints, assist flex second, third, fourth fingers at MCP joints, assist extend second, third, fourth fingers at IP joints

N: ulnar C8, T1

Question 12

Abductor Digiti Minimi

Answer 12

O: pisiform and tendon of flexor carpi ulnaris

I: base of proximal phalanx of fifth finger, ulnar surface

A: abduct fifth finger, assist opposition of fifth finger towards thumb

N: ulnar C(7), 8, T1

Question 13

Flexor Digiti Minimi Brevis

Answer 13

O: hook of hamate and flexor retinaculum

I: base of proximal phalanx of fifth finger, palmar surface

A: flex fifth finger, assist opposition of fifth finger towards thumb

N: ulnar C(7), 8, T1

Question 14

Opponens Digiti Minimi

Answer 14

O: hook of hamate, flexor retinaculum

I: shaft of fifth metacarpal, ulnar surface

A: opposition or fifth finger at MCP joint

N: ulnar C(7), 8, T1