Phar 341- La

Front 1

"__________ located in tissue signal tissue damage or trauma"

Back 1

Pain Receptors (nociceptors)

Front 2

Pain stimulus converted into a nerve signal that travels along peripheral nerves to the ________ (head) or _______ (body).

Back 2

Brainstem, Spinal Cord

Front 3

Processing occurs in _______ first and then the _______ where it reaches conscious perception.

Back 3

Thalamus, Cortex

Front 4

What is the order that function is lost due to Local Anesthetic?

-Touch

-Motor Control

-Temperature/Pain

-Proprioception (joint position)

Back 4

1) Temperature/Pain [small fibres]

2) Touch [medium fibres]

3) Proprioception (joint position) [large fibres]

4) Motor Control [large fibres]

Front 5

Large diameter ___ fibres transfer information to the brain very quickly because they are thickly covered by an insulator called myelin.

Back 5

A (fibres)

Front 6

What functions are transferred via Large A fibres (A-alpha, A-beta)?

Back 6

Sense muscle position, reflex activity, touch and pressure

Front 7

The smallest A fibres (A-delta) conduct nerve impulses more slowly because they are _______?

Back 7

Thinly Myelinated

Front 8

What functions are transferred via small A fibres (A-delta)?

Back 8

Pain & Temperature

Front 9

Smaller, ____ fibres lack myelin and conduct nerve impulses extremely slowly.

Back 9

C

Front 10

What functions are transferred via C fibres ?

Back 10

Pain & Temperature

Front 11

What is the structural difference between A fibres and C fibres?

Back 11

A fibres have Myelin, while C fibres lack Myelin.

Front 12

Large fibres conduct impulses quickly because they have large _______ distances (gaps)

Back 12

Intra-Nodal

Front 13

Nerves conduct information to the brain from tissues through the generation of _______ _______?

Back 13

Action Potentials

Front 14

Action potentials are propagated along the nerve as a result of a:

A) Passive process which allows current to flow from down the axon

B) Active process involving the opening of potassium & chloride channels

C) Active process involving the opening of sodium & potassium channels

D) A combination of a) and c)

Back 14

Answer: D

Front 15

How do impulses travel along the nerve from the tissues to the brain?

Back 15

Electrical impulses are generated at the terminals and travel up the nerve fibre through the opening of sodium channels in the axon membrane.

Front 16

To block electrical conduction in nerve fibres, several ______ need to be affected ?

Back 16

Nodes

[note: this is why it takes a longer time to inhibit motor function ]

Front 17

What are two example of Sodium Channel Blockers ?

Back 17

Tetrodotoxin (TTX)

Saxitoxin (STX)

Front 18

Which Sodium Channel Blocker is found in puffer fish testes and fugu?

Back 18

Tetrodotoxin (TTX)

Front 19

Which Sodium Channel Blocker is found in dinoflagellates and filter feeding shellfish (clams, mussels etc.) ?

Back 19

Saxitoxin (STX)

Front 20

How long does it take the body to remove the sodium channel blockers ?

Back 20

About an hour

Front 21

TTX and STX bind to a specific receptor on the ________ of the sodium channel to prevent sodium influx.

Back 21

Outside

Front 22

General chemical structure of Amide?

Back 22

Front 23

General chemical structure of Ester?

Back 23

Front 24

Why do local anesthetics need to have a lipophilic group ? (usually an aromatic group)

Back 24

To pass through the membrane bilayer, in order to block the sodium channel from the INSIDE.

Front 25

What causes the stinging sensation when you are injected with a local anesthetic?

Back 25

Due to the low pH of the drug kept in and when it is buffered

Front 26

How do you think it was determined that amides and esters LA work from inside the axon?

Back 26

A quaternary amine (which normally cannot pass due its positive charge) will work if injected directly into an axon but not when outside the axon.

Front 27

What is "Redistribution"?

Back 27

Body's blood stream tries to take compounds found locally and redistribute them throughout the body.

Front 28

How are esters and amides broken down?

Back 28

Esters – broken down by plasma esterases

Amides – broken down in liver by N-dealkylation and hydrolysis.

Front 29

"High concentrations (mM) of local anesthetics are used to achieve a block."

True or False?

Back 29

True: Increases the driving force to cross the axon membrane.

Front 30

"Hydrophobicity decreases potency of Local Anesthetics"

True or False?

Back 30

False: Hydrophobicty Increases ability of drug to cross the axon membrane.

Front 31

"Rate of metabolism is unimportant to the duration of a local anesthetic block. "

True or False?

Back 31

True: Rate of Redistribution determines block length. (Toxicity is affected by the Rate of Metabolism)

Front 32

" Lowering the pH can increase block efficacy and duration of local anesthetics"

True or False?

Back 32

False: Decreases the amount of uncharged drug, which decreases the amount passing into the axon, as well as increase the Redistribution rate (which would decrease duration).

Front 33

"Co-injected vasoconstrictors (e.g. epinephrine) can lengthen block duration. "

True or False?

Back 33

True: Delays the Redistribution rate, because the blood flow is much slower.

Front 34

What are the various routes of administration of local anesthetics?

Back 34

-Topical/ Surface

-Infiltration (directly into affected tissue)

-Nerve Block (near but NOT into the nerve)

-Spinal (Subarachnoid or Intrathecal Injection)

-Epidural (Into the fat surrounding the nerve)

Front 35

Which is faster to onset time, Spinal Anesthesia or Epidural Injection?

Back 35

Spinal is faster (5-10 mins), Epidural has more barriers to diffusion.

Front 36

What are the symptoms of central nervous system toxicity?

Back 36

Initial nervousness, dizziness, blurred vision and tremors (or lip tingling)

Later drowsiness, convulsions, unconsciousness and respiratory arrest

Front 37

What causes central nervous system toxicity?

Back 37

Direct effect of local anesthetics on neuronal sodium channels.

Front 38

What are the symptoms of cardiotoxicity?

Back 38

Hypotension, cardiovascular collapse, bradycardia and cardiac arrest.

Front 39

What causes cardiotoxicity?

Back 39

Direct effect of local anesthetics on cardiac and arteriolar sodium channels.

[Indirect effect due to sympathetic blockade (spinal/epidural) and central nervous system]

Front 40

Which Local Anesthetics are administered topically?

Back 40

Benzocaine (skin/mucous membranes)

Lidocaine

Bupivacaine

Front 41

Which Local Anesthetics are administered via infiltration?

Back 41

Procaine (dental)

Lidocaine

Bupivacine

Front 42

What are the routes of administration for Procaine?

Back 42

Infiltration (dental)

Front 43

What are the routes of administration for Benzocaine?

Back 43

Topical (skin/mucous membranes)

Front 44

What are the routes of administration for Lidocaine?

Back 44

All routes: topical, infiltration, epidural, caudal, spinal

Front 45

What are the routes of administration for Bupivacaine?

Back 45

All routes: topical, infiltration, epidural, caudal, spinal