Muscles of the hand

Question 1

What is the proximal attachment of the opponens pollicis, abductor pollicis brevis, and flexor pollicis brevis?

Answer 1

Flexor retinaculum and tubercles of scaphoid and trapezium

Question 2

What is the distal attachment of the opponens pollicis?

Answer 2

First metacarpal

Question 3

What nerve innervates the opponens pollicis and abductor pollicis brevis?

Answer 3

Recurrent branch of median nerve (C8, T1)

Question 4

What is the main action of the opponens pollicis?

Answer 4

• Oppose thumb

- draws first metacarpal medially to center of palm

Question 5

What is the distal attachment of the abductor pollicis brevis and the flexor pollicis brevis?

Answer 5

Proximal phalanx of thumb

Question 6

What is the main action of the abductor pollicis brevis?

Answer 6

-Abducts thumb and helps to oppose it

Question 7

What is the main action of the flexor pollicis brevis?

Answer 7

-Flexes thumb

Question 8

What is the proximal attachment of the adductor pollicis?

Answer 8

Oblique head: bases of 2nd and 3rd metacarpals, capitate, and adjacent carpals
Transverse head: shaft of 3rd metacarpal

Question 9

What is the distal attachment of the adductor pollicis?

Answer 9

Proximal phalanx of thumb

Question 10

What nerve innervates the flexor pollicis brevis?

Answer 10

Superficial head: recurrent branch of median nerve (C8,T1)

Deep head: Deep branch of ulnar nerve (C8, T1)

Question 11

What nerve innervates the adductor pollicis?

Answer 11

Deep branch of ulnar nerve (C8, T1)

Question 12

What is the main action of the adductor pollicis?

Answer 12

-Adducts thumb toward lateral border of palm

Question 13

What is the proximal attachment of the abductor digiti minimi?

Answer 13

Pisiform

Question 14

What is the distal attachment of the abductor digiti minimiand the flexor digiti minimi brevis?

Answer 14

Proximal phalanx of 5th digit

Question 15

What nerve the abductor digiti minimi, flexor digiti minimi brevis, and the opponens digiti?

Answer 15

Deep branch of ulnar nerve (C8, T1)

Question 16

What is the main action of the abductor digiti minimi?

Answer 16

• Abducts 5th digit

- Assists in flexion of its proximal phalanx

Question 17

What is the proximal attachment of the flexor digiti minimi brevis and the opponens digiti?

Answer 17

Hook of hamate and flexor retinaculum

Question 18

What is the main action of the flexor digiti minimi brevis?

Answer 18

-Flexes proximal phalanx of 5th digit

Question 19

What is the distal attachment of the opponens digiti?

Answer 19

5th metacarpal

Question 20

What is the main action of the opponens digiti?

Answer 20

-Draws 5th metacarpal anterior and rotates it, bringing 5th digit into opposition with thumb

Question 21

What is the proximal attachment of the 1st and 2nd lumbricals?

Answer 21

Lateral two tendons of flexor digitorum profundus (as unipennate muscles)

Question 22

What is the distal attachment of the 1st-4th lumbricles?

Answer 22

Lateral sides of extensor expansions of 2nd-5th digits

Question 23

What nerve innervates the 1st and 2nd lumbricles?

Answer 23

Median nerve (C8, T1)

Question 24

What is the main action of the 1st-4th lumbricles?

Answer 24

• Flex metacarpophalangeal joints

- extends interphalangeal joints of 2nd-5th digits

Question 25

What is the proximal attachment of the 3rd and 4th lumbricles?

Answer 25

Medial three tendons of flexor digitorum profundus (as bipennate muscles)

Question 26

What nerve innervates the 3rd and 4th lumbricles?

Answer 26

Deep branch of ulnar nerve (C8,T1)

Question 27

What is the proximal attachment of the dorsal interossei 1st-4th?

Answer 27

Adjacent sides of two metacarpals (as bipennate muscles)

Question 28

What is the distal attachment of the dorsal interossei?

Answer 28

Proximal phalanges; extensor expansions of 2nd-4th digits

Question 29

What nerve innervates the dorsal interossei and the palmar interossei?

Answer 29

Deep branch of ulnar nerve (C8, T1)

Question 30

What is the main action of the dorsal interossei?

Answer 30

- Abduct 2nd-4th digits from axial line | - helps flex metacarpophalangeal joints and extends interphalangeal joints

Question 31

What is the proximal attachment of the palmar interossei 1st-3rd?

Answer 31

Palmar surfaces of 2nd, 4th, and 5th metacarpals (as unipennate muscles)

Question 32

What is the distal attachment of the palmar interossei?

Answer 32

Proximal phalanges and extensor expansions of 2nd, 4th, and 5th digits

Question 33

What is the main action of the palmar interossei?

Answer 33

-Adducts 2nd, 4th, and 5th digits toward axial line