Exam 2 material: spinal roots

Question 1

Major arm dermatome: C5

Answer 1

overlying lateral upper arm

Question 2

Major arm dermatome: C6

Answer 2

Lower arm, thumb, lateral index finger (6-shooter)

Question 3

Major arm dermatome: C7

Answer 3

middle hand, finger

Question 4

Major arm dermatome: C8

Answer 4

medial hand, ring/pinky fingers

Question 5

Major arm dermatome: T1

Answer 5

medial side of arm

Question 6

Major trunk dermatome: T4

Answer 6

runs across nipple

Question 7

Major trunk dermatome: T10

Answer 7

runs across umbilicus (belly button)

Question 8

Major trunk dermatome: T12

Answer 8

inguinal ligament (bottom of thorax at groin)

Question 9

Major leg dermatome: L1/2/3

Answer 9

-anterior upper leg

“candycane” down leg (higher laterally and goes lower medially)

Question 10

Major leg dermatome: L3/4

Answer 10

crosses patella

Question 11

Major leg dermatome: L4

Answer 11

anterior, medial lower leg

Question 12

Major leg dermatome: L5

Answer 12

anterior, lateral lower leg and medial foot (big toe)

Question 13

Major leg dermatome: S1

Answer 13

lateral foot, posterior lower leg

Question 14

Major leg dermatome: S2

Answer 14

Posterior upper leg

Question 15

Major leg dermatome: S3/4

Answer 15

Buttocks/perianal

Question 16

Myotomes: C5

Answer 16

elbow flexion, arm abduction (deltoid/biceps)

Question 17

Myotomes: C6

Answer 17

wrist extension

Question 18

Myotomes: C7

Answer 18

elbow extension (triceps)

Question 19

Myotomes: C8

Answer 19

finger flexors

Question 20

Myotomes: T1

Answer 20

finger abduction

Question 21

Myotomes: L1/2

Answer 21

hip flexion (iliopsoas)

Question 22

Myotomes: L3/4

Answer 22

knee extension (quads)

Question 23

Myotomes: L4

Answer 23

ankle dorsiflexion

Question 24

Myotomes: L5

Answer 24

big toe dorsiflexion… extension? (extensor hallucis longus)

Question 25

Myotomes: S1

Answer 25

ankle plantarflexion

Question 26

what nerve root does this reflex: biceps

Answer 26

C5/6

Question 27

what nerve root does this reflex: brachioradialis

Answer 27

C6

Question 28

what nerve root does this reflex: triceps

Answer 28

C7

Question 29

what nerve root does this reflex: patellar

Answer 29

L3/4

Question 30

what nerve root does this reflex: Achilles

Answer 30

S1

Question 31

Answer 31

Question 32

Brachial plexus

Answer 32

* Segments * roots * trunks * divisions * cords * branches

Question 33

Erb-Duchenne palsy (injury to what and presented as what?)

Answer 33

* injury to upper trunk * combined C5/6 injury * usually due to downward traction on shoulder/arm relative to head * commonly seen after births complicated by a stuck shoulder (shoulder dystocia) * Presented as "_Waiter's tip_" * adducted shoulder * extended elbow * arm IR * wrist in flexion

Question 34

Klumpke's palsy (injury to what and presented as what?)

Answer 34

* injury to lower trunk * combined C8/T1 injury * usually due to upward traction on arm relative to head * commonly seen in children being pulled up by arms, or people breaking their fall by catching onto something (and subsequently jerking their arm/shoulder upwards) * presented as "_Claw hand_" * similar to combined median/ulnar palsy * loss of intrinsic hand function * all fingers over extended from long extensors * (just FYI - distal joints actually flex because of long flexors making the claw-like appearance)

Question 35

Lumbosacral plexus (injury and nerves)

Answer 35

* less commonly injuried * can be injured in trauma, or as part of abdominal/pelvic pathologies * nerves * femoral * from roots L2-L4 * involved in cutaneous sensation to leg and upper leg function * obturator * from roots L2-L4 * primarily controls proximal leg muscles * Sciatic * from roots L4-S4 * controls posterior leg, lower leg, and lower leg sensation

Question 36

Radial nerve (major sensory and motor areas)

Answer 36

* majory sensory * posterior hand * lesions around axilla will also affect posterior/lateral upper arm * major motor * triceps (C7) * Brachioradialis (C6) * Wrist extensors (C6) * supinator (C6/7) * abductor pollicis longus (C7)

Question 37

Median nerve (major sensory and motor areas)

Answer 37

* major sensory * lateral fingers, palm * \*\*\*with lesions in carpal tunnel, only fingers * Major motor * Pronator teres (C6/7) * Flexor digitorum superficialis/profundus (digits I and II) (C8) * opponens pollicis (T1)

Question 38

Ulnar nerve (major sensory and motor areas)

Answer 38

* Major sensory * medial hand/fingers * injury distal to branches can spare regions * distal to dorsal cutaneous branch: dorsal hand spared * distal to palmar cutaneous branch: palm of hand spared * Major motor * flexor digitorum profundus (digits III and IV) (C8) * abductor digiti minimi (C8/T1) * adductor pollicis (T1)

Question 39

Thumb motor control

Answer 39

* RUM! * Radial nerve: abduction * Ulnar nerve: adduction * Medial nerve: opposition

Question 40

Wrist drop

Answer 40

* radial palsy

Question 41

Preacher's hand

Answer 41

* median nerve palsy * (try to close hand and first 3 fingers dont close)

Question 42

Ulnar claw

Answer 42

* ulnar palsy *

Question 43

"simian hand"

Answer 43

* Median and ulnar palsy

Question 44

Common peroneal nerve (major sensory and motor areas)

Answer 44

* Major sensory * Lateral leg * dorsal foot * Major motor * peroneus longus/brevis (L5/S1; foot eversion) * tibialis anterior (L4; foot dorsiflexion) * Extensor digitorum/hallucis longus (L5; toe extension)

Question 45

Tibial nerve (major sensory and motor areas)

Answer 45

* Major sensory: * bottom of foot * major motor * gastroc/soleus (S1/2) * Tibialis posterior (L4/5; foot inversion) * Flexor digitorum/hallucis longus (S1/2)