Chapter 4: Exam 1

Question 1

what are the 3 main components to the structure of anesthetics

Answer 1

aromatic ring, intermediate chain, and terminal amine

Question 2

an aromatic ring contains ___________ properties, has ____________ which allows the anesthetic to penetrate the nerve membrane, and determines the _______________ of the drug

Answer 2

lipophilic
lipid solubility
potency/concentration

Question 3

an intermediate chain is either an _________ or ___________. it distinguishes the type of ___________ and determines the site of ______________

Answer 3

ester or amide
anesthetic
biotransformation

Question 3

the terminal amine has _____________ properties, has water solubility that ensures the drug will not precipitate on exposure to ____________, and allows the agent to disperse in the ________ and ___________ fluids

Answer 3

hydrophilic
interstitial fluid
intracellular and extracellular

Question 4

in natural form, local anesthetics are weak ________ meaning their poorly soluble in water

Answer 4

bases

Question 5

in cartridges, LA solution is acidified to form stable __________

Answer 5

salts

Question 6

to be stable in solution, the ph of anesthetic must favor water soluble _________ at the time of injection

Answer 6

cations

Question 7

this is uncharged or neutral and penetrates nerve membranes

Answer 7

base

Question 8

this has a positive charge, bind to the receptor site, and effects the duration of the anesthetic

Answer 8

cation

Question 9

primarily effects diffusion, onset times, and success

Answer 9

ionization

Question 10

after injection into the tissue, the equilibrium shifts from cationic to ___________ due to pH of normal tissue

Answer 10

neutral base

Question 11

for the anesthetic to pass through the membrane, RNH+ converts to _____

Answer 11

RN

Question 12

depleted RN in the _________ causes the equilibrium to produce more RN

Answer 12

extracellular fluid

Question 13

once anesthetic is exposed to the axoplasm, the equilibrium shift to favor ________

Answer 13

RNH+

Question 14

__________ ions are available in the axoplasm

Answer 14

hydrogen

Question 15

blocked channel = no __________ = no impulse

Answer 15

sodium

Question 16

during the resting stage, __________ ions are bound to receptor sites within the ion channels of cell membranes

Answer 16

calcium (Ca++)

Question 17

during slow depolarization, local anesthetics compete with _______ to bind to the ion channels and to close off these channels

Answer 17

Ca++

Question 18

during depolarization, __________ are displaced, which is thought to be the most significant factor responsible for the influx of _________ into the nerve

Answer 18

Ca++
sodium

Question 19

percentages of RNH+ and RN are manipulated by the ________

Answer 19

pH

Question 20

local anesthetic solution has more __________ than _________

Answer 20

RNH+
RN

Question 21

what are the benefits to pH in local anesthetics

Answer 21

great stability
increased solubility
ease of sterilization

Question 22

increasing the pH of a solution/surrounding tissues with increase __________ molecule concentrations

Answer 22

neutral base

Question 23

lowering ph will favor ________ concentrations

Answer 23

cation

Question 24

pKa is a ________________ constant

Answer 24

dissociation

Question 25

pKa is a measurement of a molecules affinity for _________ ions

Answer 25

H+

Question 26

if pKa = pH then base concentration = ____________ concentration

Answer 26

cation

Question 27

what is phase I of cns action of LA

Answer 27

cns excitation

Question 27

how is pKa determined

Answer 27

henderson hasselbalch equation

Question 28

what is phase II of cns action of LA

Answer 28

cns depression

Question 29

what are the two possible pathways of biotransformation

Answer 29

liver or blood

Question 30

the process where LA drugs are broken down to less toxic or nontoxic metabolites before being excreted

Answer 30

biotransformation

Question 31

biotransformation follows the pathway of the liver = _________________ system (slow)

Answer 31

p450 isoenzyme

Question 32

plasma cholinesterase breaks down ______________ and ____________

Answer 32

esters and articaine

Question 32

biotransformation follows pathway of blood = plasma _______________-

Answer 32

cholinesterase

Question 33

plasma cholinesterase is made by the ____________ but distributed throughout the body

Answer 33

liver

Question 34

biotransformation of amides is primarily performed by _____________ enzymes

Answer 34

liver hepatic

Question 35

what is the exception to biotransformation of amides

Answer 35

articaine

Question 36

biotransformation of esters happens in the blood by ________________

Answer 36

plasma cholinesterase

Question 37

esters break down into _______________ acid which is thought to be the source of their antigenic tendencies

Answer 37

paraamino benzoic

Question 38

what is the only injectable ester anesthetic

Answer 38

procaine

Question 39

elimination of local anesthetics is performed by the ___________

Answer 39

kidneys