Hand intrinsic Muscles

Question 1

Dorsal Interossei (origin)

Answer 1

adjacent sides of 2 metacarpal bones

Question 2

Dorsal Interossei (insertion)

Answer 2

base of proximal phalanges, extensor expansions of digits 2-4

Question 3

Dorsal Interossei (action)

Answer 3

abduct digits from axial line of hand (3rd digit); flex digits at metacarpophalangeal joint and extend interphalangeal joints

Question 4

Dorsal Interossei (innervation)

Answer 4

Ulnar nerve (deep branch)

Question 5

Palmar Interossei (origin)

Answer 5

Sides of metacarpals 2,4,5

Question 6

Palmar Interossei (insertion)

Answer 6

Bases of proximal phalanx and extensor expansion of digits 2,4,5

Question 7

Palmar Interossei (action)

Answer 7

Adducts digits toward axial line of hand (3rd digit); flexes digits at metacarpophalangeal joint and extends interphalangeal joints

Question 8

Palmar Interossei (innervation)

Answer 8

ulnar nerve (deep branch)

Question 9

Lumbricals (origin)

Answer 9

1st and 2nd: lateral two tendons of flexor digitorum profundus. 3rd and 4th: medial 3 tendons of flexor digitorum profundus

Question 10

Lumbricals (insertion)

Answer 10

1st and 2nd: lateral sides of extensor expansion of digits 2 and 3. 3rd and 4th: lateral sides of extensor expansion of digits 4 and 5

Question 11

Lumbricals (action)

Answer 11

extend digits at interphalangeal joints, flex metacarpophalangeal joints

Question 12

Lumbricals (innervation)

Answer 12

ulnar nerve (deep branch)