Week 19 Lectures

Question 1

What are the parasympathetic nerves come from?

Answer 1

CN III
CN VI
CN IX
CN X

S2 ,3,4

Question 2

Where does the visceral motor cell bodies?

Answer 2

CN III
CN VI
CN IX
CN X

T1-L2

S2,3,4

Question 3

Where does sympathetic innervation come from?

Answer 3

T1-L2

Question 4

What are the layers in a nerve

Answer 4

epineurium

perineurium

endoneurium

Question 5

Epineurium

Answer 5

surrounds entire nerve

Question 6

Perineurium

Answer 6

encapsulates bundles of axons called fascicles

Question 7

Endoneurium

Answer 7

m contained within the perineurium consists of axons

Question 8

Axons require _______. _________ with soma for viability

Answer 8

Axons require cytoplasmic continuity with soma for viability

Question 9

2 types of schwann cells associted with axons

Answer 9

1) myelinating
2) ensheathing

Question 10

What 2 main variables influence AP propagation rate

Answer 10

1) Fibre diameter – larger diameter = faster AP propagation rate
2) Myelin - greater the thickness and segmental length of myelin = faster APs

Question 11

Two classification schemes for Peripheral nerve axons

Answer 11

1) Conduction Velocity

A-fastest myelinated

alpha,beta, delta,gamma

B-slower myelinated

• C-smallest unmyelinated
  2) Diameter

I,II,III,IV

a,b

• for sensory axons only

Question 12

Special senses

Answer 12

The special senses are modalities carried by cranial nerves

Olfaction – CN. I

• Vision – CN. II
• Taste – CN. VII and CrN IX
• Hearing and balance (equilibrium) – CN. VIII

Question 13

The general or somatic senses (Somatosensory)

Answer 13

Detected from all parts of the body (and head) and transmitted to CNS via:

• CN. V (trigeminal)
• All spinal nerves except CN.1

Question 14

what is different about the Generating potential in the optic compared to all other cell types?

Answer 14

It is a hyperpolarization rather then a depolarztion

Question 15

Where do the fibres for sensory of the body terminate

Answer 15

the VPL (Ventral posterolateral nucleus)

Question 16

Where do the sensory fibres of the head-synapse in the thalamus?

Answer 16

VPM

Question 17

Which sensory pathway is Lissauer tract a part of?

Answer 17

Spinothalamic tract

Question 18

What do 3rd order neurons for sensory touch and pain travel through when traveling from the thalamus to the postcentral gyrus?

Answer 18

The internal capsule

Question 19

Where do the motor neurons cross for the anterior corticospinal tract?

What is the percentage of fibres here?

Answer 19

It crosses in the spinal cord

15%

Question 20

_- Motor neurons innervate ______ fibres which are responsible for muscle ________.

Answer 20

alpha- Motor neurons innervate extrafusal fibres which are responsible for muscle contraction.

Question 21

How long do we have to reattach nerves if they are cut?

Answer 21

~12 months sooner is better!

Question 22

What are the clues that a disease is demylinating (5)

Answer 22

1) Weakness without atrophy
2) Rapidly ascending
3) preceding infection
4) Areflexia
5) patchy distribution non-lenght dependent

Question 23

peripheral neuropathy caused by diabetes is _______ and length _________

Answer 23

peripheral neuropathy caused by diabetes is Axonal and length dependent

Question 24

Investigations lab tests for peripheral neuropathy (6)

Answer 24

1) CBC
2) A1C/ Blood glucose
3) B12
4) ESR- erythrocyte sedimentation rate_ inflammation
5) TSH
6) Serum protein electrophorisis

Question 25

Positive motor symptoms for a peripheral neuropathy

Answer 25

Cramps/ twitching

Question 26

Positive sensory symptoms for peripheral neuropathy? (5)

Answer 26

1) paresthesia- Tingling pins and needles 2) burning 3) stabbing pain 4) Allodynia- discomfort to stimuli that are not typically painful 5) Hyperalgesia- Increased sensitive to pain stimuli

Question 27

What are the negative motor symptoms for peripheral neuropathy symptoms?

Answer 27

Weakness Atrophy

Question 28

What are the negative symptoms for peripheral neuropathy?

Answer 28

1) Reduce sensation/numbness 2) Gair ataxia/imbalance

Question 29

What are some of the Autonamic symptoms of peripheral neuropathy? (4)

Answer 29

1) Cardiac 2) GI 3) Genitourinary 4) Vasomotor - cold extremities - skin color changes

Question 30

Fill in this table:

Answer 30

Question 31

Whar are the three categories of peripheral neuropathy and the types of neuropathy under those categories?

Answer 31

1) Focal - Mononeuropathy: a single nerve - Radiculopathy: A single nerve root 2) Multifocal PolyRadiculopathy Mononeuropathy multiplex 3) diffuse Polyneuropahty

Question 32

Explain Lenght dependent polyneuropathy pathology

Answer 32

metabolic function is in the neuron cell body and then nutrients are transported down axon if there is a defect in this the distal axons die first

Question 33

what are some causes of distal axonapathy? (4)

Answer 33

1) diabetes 2) nutrient defiency 3) Toxins ETOH/ chemo 4) hereditary neuropathy

Question 34

What are the red flag signs that something is not a Distal axonopathy (5)

Answer 34

1) Asymmetry of onset and findings 2) Cranial nerve involvment 3) Motor\> sensory 4) disproportionate reflex changes (Areflexia with mild symptoms) 5) Rapid progression with significant deficit over acute

Question 35

What is a Radiulopathy what is a example of this?

Answer 35

It involves a single nerve root. example is Sciatica

Question 36

What is mononeuropathy? what is an example of this?

Answer 36

Lesion of a single nerve, Carpal tunnel, medial nerve

Question 37

What is the order that we give drugs for neuropathic pain

Answer 37

1) Gabapentinoids/TCAs/SNRIs 2) Tramadol/Opiod ???? 3) Cannabinoids 4) 4th line agents

Question 38

What is a marker in CFS that is indicative of GBS?

Answer 38

Albuminocytologic dissociation

Question 39

What is the gene that causes an CMT1A? Is those a demylinateing or axonal

Answer 39

PMP22 CMT1a is Demylinating

Question 40

What are some key features of CMT (3)

Answer 40

Often have distal weakness and sensory loss with little disability presence of pes caus and hammertoes family history

Question 41

The acute onset of perpherial neuropahty in the distribution of individual nerves is suggestive of what?

Answer 41

Vasculitis

Question 42

What are 3 ways to damage a nerve?

Answer 42

1) Ischaemia 2) Compression 3) Cut

Question 43

Neuropraxia

Answer 43

Demylinationg of a nerve. can be reduced thickness, to multiple segments of no myelin

Question 44

What happens when a nerve is cut and needs to regenerate?

Answer 44

1) Trophic factors and cytokines released by damaged Schwann cells 2) Macrophages come clean up 3) dedifferentiate Schwann cells mylin loss 4) distal end degenerates (Wallerian degeneration ) 4) triggers proliferation of indifferent Schwann cells which some become new new myelinating cells 5) Sprouts produced at cut end

Question 45

What happens if a regenerating nerve cant reattach to a muscle

Answer 45

Neuroma- painful

Question 46

Tinels sign

Answer 46

At the Proximal end of the cut nerve can tap and will get a tingling sensation can tell you where the leading edge of regeneration is

Question 47

What are the two classes of Local anesthetics?

Answer 47

Aminoesters aminoamides

Question 48

How do LA's work

Answer 48

they attach to the inactivated Na channel and stop the regeneration of an Axon potential. Most work from inside the cell

Question 49

What is the difference between Bupivacaine and ropivacaine?

Answer 49

Bupivacaine is more cardiotoxic because it has a R and S enatiomers Ropivacaine has just and S-isomer Both are CNS toxic

Question 50

How do LAs cross into cells

Answer 50

LAs are amphoteric based on their pkas they dissociate into a base and charged cation. the base will cross the cell membranes and the cation works inside the cell to inhibit the Na chanel

Question 51

How do waling epidurals work?

Answer 51

LAs will target smaller unmyelinated fibres first. therefore the pain and temp fibres Type A-delta and C fibres will be target first and block pain and temp but not proprioception

Question 52

Details about Benzocain (3)

Answer 52

1) aminoester 2) Used as topical anesthesia only 3) risk for methemoglobin (cyanosis)

Question 53

Details about Lidocaine (3)

Answer 53

1) Aminoamide 2) Fast onset 3) used as IV as an antiarrhythmic and in acute and chronic pain

Question 54

Details about Bupivacaine (2)

Answer 54

Lipophilic and potent long duration of action R isomer has high cardiotoxicity good sencory motor seperation

Question 55

Ropivacaine detials

Answer 55

1) s isomer only of bupivacaine less cardiotoxic even more motor sparing then bupivacaine

Question 56

Never inject a La with a **\_\_\_\_\_\_\_\_ i**nto peripheral body parts as it can cause tissue necrosis and gangrene

Answer 56

Never inject a LA with a **Vasoconstrictor** into peripheral body parts as it can cause tissue necrosis and gangrene

Question 57

LA potency cooraltes with ______ \_\_\_\_\_\_

Answer 57

LA potency correlates with Lipid solubility

Question 58

Onset of LA action cooraltes with?

Answer 58

Pka, Lower pka faster

Question 59

what is lipid rescue

Answer 59

Used to treat local anesthetic toxicity 20% lipid emulsion 1.5 ml/KF iV over a min follow with continues infusion