Anatomy 3 - spinal nerves

Question 1

what is the pattern of spinal nerve innervation of upper limb

Answer 1

comes out horizontally in development in horizontal strips along the limb buds

like putting arm through clingfilm lol

Question 2

what are somatic general sensory symptoms

Answer 2

pain 
pins and needles 
numbness 
sensitivity 
thermal 
loss of co-ordination/balance/clumsiness

Question 3

somatic motor symptoms

Answer 3

muscle stiffness, tightness, or spasm
muscle floppiness or looseness
muscular weakness
loss of co-ordination/balance/clumsiness

Question 4

what does each pair of spinal nerves do

Answer 4

supplies everything in one segment of the body wall

general somatic sensation
general somatic motor
sympathetic motor
spinal reflexes

Question 5

how do you clinically test spinal nerve function

Answer 5

test each spinal nerve segments sensory function
-dermatomes

test each spinal nerves motor function
-myotomes

test both of the above simultaneously with spinal cord reflexes

Question 6

what spinal nerves innervated the upper limb and trunk

Answer 6

C1-T12

Question 7

what dermatome is the pubic symphysis

Answer 7

T12

Question 8

what dermatome is the nipple

Answer 8

T4

Question 9

what dermatome is the umbilicus

Answer 9

T10

Question 10

what spinal nerves innervated the lower limb

Answer 10

L1 (groin) - S5 (perianal skin)

Question 11

how does dermatomal testing check the integrity of

Answer 11

dorsal rootlets
dorsal root
spinal nerve

Question 12

what rami forms plexuses

Answer 12

anterior rami

cervical plexus
brachial plexus
lumbar plexus
sacral plexus

Question 13

what anterior rami do not contribute to a plexus

Answer 13

T2-T12

Question 14

what spinal nerve roots make up the femoral nerve

Answer 14

L2, L3 and L4

Question 15

what named nerves are from cervical spinal roots C2-C8

Answer 15

little - lesser occipital (C2)
goats - Great auricular nerve (C2,C3)
tread - Transverse cervical (C2,3)
softy - Supraclavicular nerves (C3,4)

Question 16

what are the named nerve cutaneous innervation of the upper limb

Answer 16

Supraclavicular nerves (C3,4) 
Axillary nerve (C5,6) 
Cutaneous branch of the musculocutaneous nerve (C5,6,7) 
Median nerve (C5,6,7,8,T1)
Ulnar nerve (C7,8,T1)

Question 17

what are the named nerve cutaneous innervation of the leg (anterior)

Answer 17

Subcostal nerve (T12) 
Femoral branch of genitofemroal never (L1,2) 
Ilioinguinal nerve (L1) 
Obturator nerve (L2,3,4) 
Lateral cutaneous nerve of thigh (L2,3) 
Femoral nerve (L2,3,4) 
Saphenous nerve (from femoral L3,4) 
Superficial fibular nerve (L4,L5, S1) 
Deep fibular nerve (L5)

Question 18

Sensory pathway side

Answer 18

look at it idk

Question 19

where is the cervical plexus

Answer 19

C1-C4

Question 20

what is the brachial plexus

Answer 20

C5-T1

Question 21

what do T2-L3 motor axons supply

Answer 21

postural back muscles
intercostal muscles
anterolateral abdominal wall muscles

Question 22

what do lumbosacral plexus L1-S4 axons supply

Answer 22

muscles of lower limb

perineal skeletal muscles

Question 23

where is the primary motor cortex

Answer 23

pre-central gyrus

Question 24

what % of axons cross

Answer 24

85%

Question 25

what is a reflex

Answer 25

involuntary response to stimulus - depends on integrity of arc pathway

Question 26

describe the patella reflex arch (knee jerk)

Answer 26

Patella tendon tapped
Stretches the quads
Muscle spindles initiate APs in the anterior rami axons in the femoral nerve
Sensory APs conducted to the dorsal horn of L3
Axons pass into anterior horn to synapse on LMNS that supply quads
AP conduced via lower motor neuron axons on femoral nerve to reach quads neuromuscular junction

muscle contracts to extend knee joint

Question 27

what do upper motor neuron lesions cause

Answer 27

spasticity

Question 28

what do lower motor neuron lesions cause

Answer 28

flaccidity

Question 29

myotome test for L2

Answer 29

hip flexion

Question 30

if pins and needles in dermatomal pattern but motor function okay where is the lesion

Answer 30

in the posterior spinal rootlets