Wrist/Hand

Question 1

Abductor Pollicis Longus

Answer 1

Origin: posterior ulna and radius and interosseous membrane

Insertion: base of metacarpal I

Innervation: posterior interosseous nerve (C7, C8)

Function: abducts carpometacarpal joint of thumb; accessory extensor of thumb

Question 2

Extensor Pollicis Longus

Answer 2

Origin: posterior ulna and interosseous membrane

Insertion: base of distal phalanx of thumb

Innervation: posterior interosseous nerve (C7, C8)

Function: extends IP joint of thumb; can also extend carpometacarpal and MCP joints of thumb

Question 3

Extensor Pollicis Brevis

Answer 3

Origin: radius and interosseous membrane

Insertion: base of proximal phalanx of thumb

Innervation: posterior interosseous nerve (C7, C8)

Function: extends MCP and carpometacarpal joints of thumb

Question 4

Opponens Pollicis

Answer 4

Origin: trapezium and flexor retinaculum

Insertion: 1st metacarpal (radial border)

Innervation: recurrent branch of median nerve (C8, T1)

Function: medially rotates thumb

Question 5

Abductor Pollicis Brevis

Answer 5

Origin: scaphoid, trapezium, flexor retinaculum

Insertion: proximal phalanx and extensor hood of thumb

Innervation: recurrent branch of median nerve (C8, T1)

Function: abducts thumb at MCP joint

Question 6

Flexor Pollicis Brevis

Answer 6

Origin: trapezium and flexor retinaculum

Insertion: proximal phalanx of thumb

Innervation: recurrent branch of median nerve (C8, T1)

Function: flexes thumb at MCP joint

Question 7

Adductor Pollicis

Answer 7

Origin: transverse head - metacarpal III; oblique head - capitate and bases of metacarpals II and III

Insertion: base of proximal phalanx and extensor hood of thumb

Innervation: deep branch of ulnar nerve (C8, T1)

Function: adducts thumb

Question 8

Abductor digit minimi

Answer 8

Origin: pisiform

Insertion: proximal phalanx of little finger

Innervation: deep branch of ulnar nerve (C8, T1)

Function: abducts 5th digit at MCP joint

Question 9

Flexor Digiti minimi brevis

Answer 9

Origin: hook of the hamate and flexor retinaculum

Insertion: proximal phalanx of little finger

Innervation: deep branch of ulnar nerve (C8, T1)

Function: flexes 5th digit at MCP joint

Question 10

Opponens Digiti

Answer 10

Origin: hook of hamate and flexor retinaculum

Insertion: 5th metacarpal

Innervation: deep branch of ulnar nerve (C8, T1)

Function: laterally rotates metacarpal V

Question 11

Lumbricals

Answer 11

Origin: tendons of flexor digitorum profundas

Insertion: extensor hoods of digits 2-5

Innervation: medial 2 by deep branch of the ulnar nerve; lateral 2 by digital branches of median nerve

Function: flexes MCP joints while extending IP joints

Question 12

Dorsal Interossei

Answer 12

Origin: adjacent sides of metacarpals

Insertion: extensor hood and base of proximal phalanges of digits 2-4

Innervation: deep branch of ulnar nerve (C8, T1)

Function: abduction of digits 2-4 at MCP joint

Question 13

Palmar interossei

Answer 13

Origin: side of metacarpals

Insertion: extensor hoods of thumb, index, ring, and little finger and proximal phalanx of thumb

Innervation: deep branch of ulnar nerve (C8, T1)

Function: adduction of thumb, index, ring, and little finger at MCP joint