Hand Intrinsics

Question 1

Abductor Pollicis Brevis

Answer 1

O: Scaphoid and trapezium, flexor retinaculum
I: Base of proximal phalanx of 1st digit via radial sesamoid
Inn: Recurrent branch of the Median n. (C8-T1)
A: Abduction of CMC of 1st digit

Question 2

Flexor Pollicis Brevis

Answer 2

O: Superficial head- Flexor retinaculum
Deep head- capitate, trapezium
I: Base of proximal phalanx of 1st digit via radial sesamoid
Inn: Superficial head- Recurrent branch of median n. (C8-T1)
Deep head- Deep ulnar n.
A: Flexion of CMC of 1st digit

Question 3

Opponens Pollicis

Answer 3

O: Trapezium
I: Radial border of 1st metacarpal
Inn: Recurrent Branch of the Median n. (C8-T1)
A: Opposition of the 1st digit

Question 4

Opponens digiti minimi

Answer 4

O: Hook of hamate, flexor retinaculum
I: Ulnar border of 5th metacarpal
Inn: Deep Ulnar n. (C8-T1)
A: Opposition of the 5th digit

Question 5

Flexor digiti minimi

Answer 5

O: Hook of hamate, flexor retinaculum
I: Base of 5th proximal phalanx
Inn: Deep Ulnar n. (C8-T1)
A: Flexion of MCP 5th digit

Question 6

Abductor digiti minimi

Answer 6

O: Pisiform
I: Ulnar base of 5th proximal phalanx and dorsal digital expansion of 5th digit
Inn: Deep Ulnar n. (C8-T1)
A: Flex and Abd of 5th digit. Ext of PIP and DIP

Question 7

Lumbricals 1-2

Answer 7

O: Radial side of tendons of flexor digitorum profundus
I: 1st- 2nd digit (dde). 2nd- 3rd digit (dde)
Inn: Common Palmar digital n. (Median n.) (C8-T1)
A: Flex of MCP. Ext of PIP and DIP

Question 8

Lumbricals 3-4

Answer 8

O: Tendons of flexor digitorum profundus
I: 3rd- 4th digit (dde). 4th- 5th digit (dde)
Inn: Deep Ulnar n. (C8-T1)
A: Flex of MCP. Ext of PIP and DIP

Question 9

Dorsal Interossei 1

Answer 9

O: 1st and 2nd metacarpals (adjacent sides)
I: 2nd digit (dde). 2nd proximal phalanx (radial side)
Inn: Deep Ulnar n. (C8-T1)
A: Flex of MCP. Ext and Abd of PIP and DIP from 3rd digit

Question 10

Dorsal Interossei 2

Answer 10

O: 2nd and 3rd metacarpals (adjacent sides)
I: 3rd digit (dde), 3rd proximal phalanx (radial side)
Inn: Deep Ulnar n. (C8-T1)
A: Flex of MCP. Ext and Abd of PIP and DIP from 3rd digit

Question 11

Dorsal Interossei 3

Answer 11

O: 3rd and 4th metacarpals (adjacent sides)
I: 3rd digit (dde), 3rd proximal phalanx (ulnar side)
Inn: Deep Ulnar n. (C8-T1)
A: Flex of MCP. Ext and Abd of PIP and DIP from 3rd digit

Question 12

Dorsal Interossei 4

Answer 12

O: 4th and 5th metacarpals (adjacent sides)
I: 4th digit (dde), 4th proximal phalanx (ulnar side)
Inn: Deep Ulanr n. (C8-T1)
A: Flex. of MCP. Ext and Abd of PIP and DIP from 3rd digit

Question 13

Palmar Interossei 1

Answer 13

O: 2nd metacarpal (ulnar side)
I: 2nd digit (dde), 2nd proximal phalanx (base)
Inn: Deep Ulnar n. (C8-T1)
A: Flex of MCP. Ext and Add of PIP and DIP toward 3rd digit

Question 14

Palmar Interossei 2

Answer 14

O: 4th metacarpal (radial side)
I: 4th digit (dde), 4th proximal phalanx (base)
Inn: Deep Ulnar n. (C8-T1)
A: Flex of MCP. Ext and Add of PIP and DIP toward 3rd digit

Question 15

Palmar Interossei 3

Answer 15

O: 5th metacarpal (radial side)
I: 5th digit (dde), 5th proximal phalanx (base)
Inn: Deep Ulnar n. (C8-T1)
A: Flex of MCP. Ext and Add of PIP and DIP toward 3rd digit

Question 16

Adductor Pollicis

Answer 16

O: Transverse head- 3rd metacarpal (palmar surface)
Oblique head- capitate, 2nd and 3rd metacarpals (base)
I: Base of proximal phalanx of 1st digit
Inn: Deep Ulnar n. (C8-T1)
A: CMC Add, MCP flex