Spinal Nerves Innervating Dermatomes and Myotomes

Question 1

Myotomes - Upper extremity abductors (deltoid, biceps brachii)

Answer 1

C-5

Question 2

Myotomes - Forearm flexors (bicepts brachii, brachioradialis), forearm pronators

Answer 2

C-6

Question 3

Myotomes - Forearm extensor (triceps brachii), wrist extensors, finger extensors

Answer 3

C-7

Question 4

Myotomes - Intrinsic hand muscles

Answer 4

C-8/T1

Question 5

Myotomes - Thigh flexion (iliopsoas)

Answer 5

L-2

Question 6

Myotomes - Leg extension (quadricepts)(knee jerk reflex)

Answer 6

L-3/4

Question 7

Myotomes - Foot dorsiflexors and Toe extensors (anterior tibial muscles)

Answer 7

L-4/5

Question 8

Myotomes - Foot plantar flexors and toe flexors (posterior tibial muscles) (Achilles tendon reflex)

Answer 8

S-1/2

Question 9

Myotomes - Anal contraction

Answer 9

S-2,3,4

Question 10

A group of muscles primarily innervated by the motor fibres of a single nerve root is known as a

Answer 10

Myotomes

Question 11

A skin area innervated by the sensory fibres of a single nerve root is known as a

Answer 11

Dermotome

Question 12

Dermatomes - shoulder

Answer 12

C-5

Question 13

Dermatomes - thumb

Answer 13

C-6

Question 14

Dermatomes - middle finger

Answer 14

C-7

Question 15

Dermatomes - little finger

Answer 15

C-8

Question 16

Dermatomes - nipple

Answer 16

T-4

Question 17

Dermatomes - umbilicus

Answer 17

T-10

Question 18

Dermatomes - Groin

Answer 18

L-1

Question 19

Dermatomes - medial foot

Answer 19

L-5

Question 20

Dermatomes - Lateral leg/foot

Answer 20

S-1

Question 21

Dermatomes - Anal area

Answer 21

S 2,3,4