Muscles of the Hand

Question 1

Muscles of the thenar: ABDUCTOR POLLICIS BREVIS

Answer 1

Origin: scaphoid, trapezium, flexor retinaculum
Insertion: proximal phalanx, extensor hood of thumb
Innervation: median nerve
Action: abduction of thumb at MCP joint

Question 2

Muscles of the thenar: FLEXOR POLLICIS BREVIS

Answer 2

Origin: trapezium, flexor retinaculum
Insertion: proximal phalanx of thumb
Innervation: median nerve
Action: flexion of thumb at MCP joint

Question 3

Muscles of the thenar: OPPONENS POLLICIS

Answer 3

Origin: trapezium, flexor retinaculum
Insertion: 1st metacarpal
Innervation: median nerve
Action: medial rotation of thumb

Question 4

Muscles of the hypothenar: ABDUCTOR DIGITI MINIMI

Answer 4

Origin: pisiform, tendo of flexor carpi ulnaris
Insertion: proximal phalanx and extensor hood of 5th digit
Innervation: ulnar nerve
Action: abduction of 5th digit at MCP joint

Question 5

Muscles of the hypothenar: FLEXOR DIGITI MINIMI BREVIS

Answer 5

Origin: hamate, flexor retinaculum
Insertion: proximal phalanx of 5th digit
Innervation: ulnar nerve
Action: flexion of 5th digit at MCP joint

Question 6

Muscles of the hypothenar: OPPONENS DIGITI MINIMI

Answer 6

Origin: hamate, flexor retinaculum
Insertion: 5th metacarpal
Innervation: ulnar nerve
Action: lateral rotation of 5th digit

Question 7

Muscles of the hand (intrinsic): PALMAR BREVIS

Answer 7

Origin: palmar aponeurosis, flexor retinaculum
Insertion: skin (medial margin of hand)
Innervation: ulnar nerve
Action: improves grip

Question 8

Muscles of the hand (intrinsic): ADDUCTOR POLLICIS

Answer 8

Origin: two heads
Transverse head - 3rd metacarpal
Oblique head - capitate, bases of 2nd & 3rd metacarpals
Insertion: proximal phalanx & extensor hood of thumb
Innervation: ulnar nerve
Action: adduction of thumb

Question 9

Muscles of the hand (intrinsic): LUMBRICALS 1-4

Answer 9

Origin: tendons of flexor digitorum profundus
Insertion: extensor hoods of digits 2-5
Innervation: medial half ulnar nerve, lateral half median nerve
Action: flexion of MCP joint while extending IP joint

Question 10

Muscles of the hand (intrinsic): DORSAL INTEROSSEI

Answer 10

Origin: adjacent shafts of metacarpals
Insertion: extensor hood and base of proximal phalanges of digits 2-4
Innervation: ulnar nerve
Action: abduction of digits 2-4

Question 11

Muscles of the hand (intrinsic): PALMAR INTEROSSEI

Answer 11

Origin: shafts of metacarpals
Insertion: extensor hoods of digits 1, 2, 4, 5 and proximal phalanx of thumb
Innervation: ulnar nerve
Action: adduction of digits 1, 2, 4, 5