LESSON 4: CARDIOVASCULAR DRUGS

Question 1

what is the role of potassium in RMP?

Answer 1

making the membrane polarized w/ negative & positive side

Question 2

RMP of myocardial cells is controlled by?

Answer 2

intracellular & extracellular ions

Question 3

what is the usual concentration of potassium ion?

Answer 3

[k+]i= 150mM & [K+]o= 4mM

Question 4

what is the role of sodium ion in RMP?

Answer 4

making myocardial cell undergo partial depolarization, by decreasing outflow of K.

Question 5

this level makes the membrane depolarized, that opens the sodium channels

Answer 5

threshold potential

Question 6

inabiltity of an excitable tissue to respond or to elicit action potential

Answer 6

refractoriness

Question 7

in this refractory period, at 0 to -60 mV, premature stimuli will not elicit action potential.

Answer 7

Absolute refractory period

Question 8

in this refractory period, at -60 to -90 mV, progressive reaction of Na+ channel occurs.

Answer 8

Relative refractory period

Question 9

in this refractory period, minimal interval between 2 propagating impulses.

Answer 9

Effective refractory periof

Question 10

this _____ is known as cardiac glycosides, is a drug that is important for the tx of CHF.

Answer 10

digitalis glycosides

Question 11

digitalis glycosides has the abuility to?

Answer 11

1. increase the force of myocardial contraction
2. increase cardiac output in failing heart

Question 12

digitalis glycosides are derived from?

Answer 12

plants of similar species called “fox gloves”

Question 13

what are the active glycosides of Digitalis purpuria?
: DGG

Answer 13

1. Digitoxin
2. Gitoxin
3. Gitalin

Question 14

what are the active glycoside of Digitalis lanata?
: DDG

Answer 14

1. Digitoxin
2. Digoxin
3. Gitoxin

Question 15

what is the active glycosides of Strophantus kombe?

Answer 15

1. strophantin

Question 16

what is the active glycosides of Syrophantus gratis?

Answer 16

1. Ouabain

Question 17

the skin glands of this species contain cardioactive poison, that is similar to glycosides but are for toxicological importance.

Answer 17

toad

Question 18

what is the direct action of digitalis glycosides?

Answer 18

1. It produces inotropic effect (increase forced heart contraction)
2. increase force myocardial contractuon
3. increase rate of development of myocardial tension
4. decrease time of peak tension folowed by faster relaxation

Question 19

the postive effects of digitalis is thought to be the consequence of ?

Answer 19

inhibition of sodium pump

Question 20

digitalis glycosides is made through this location, that affects the electrical activity of the purkinje , atrial, ventricular fibers that turns excitability & automacity of cardiac tissues.

Answer 20

parasympathetic autonomic nervous system

Question 21

what is the toxic level of digitalis glycosides?

Answer 21

1. RMP became less than usual
2. if RMP decrease, the action potenial also decrease
3. reduction leads to conduction of velocity

Question 22

defined as the magnitude of an electric impulse in producing action potential.

Answer 22

excitability

Question 23

this discribe the behavior by which cardiac tissue spontaneously generate action potential,

Answer 23

Automacity

Question 24

If the digitalis glycosides cause the appearance of after-depolarozation appearing immendiately ff. repolarization it may lead to?

Answer 24

Abnormal activity of the heart

Question 25

it appears as subthreshold depolarization during phase 4, it progressively increase in amplitude & reaches the threshold causing an additional action potential,

Answer 25

After depolarization

Question 26

after depolarozation may leads to an extra heartbeat called>

Answer 26

ectopic beat

Question 27

the activity of the ____ has a spontaneous depolarization of the SA node, & is slowed by parasympathetic stimulation ff, digitalis administration.

Answer 27

pacemaker activity

Question 28

effects on on other organs are considered side effects that's not beneficial to the patient.

Answer 28

Systemic side effects of digitalis

Question 29

what is the effect on normal heart of d. glycosides?

Answer 29

1. minimal increase or reduce in cardiac output 2. increase total peripheral resistance

Question 30

what is the effect on failing heart of d. glycosides?

Answer 30

1. increase contractile vigour 2. increase level of end-diastolic pressure result in complete systemic emptying of cardiac output 3. reduction of heart size 4. decrease systemic blood pressure

Question 31

what is the effects in kidney of d. glycosides?

Answer 31

1. causes diuresis when edema is present 2. diuresis is due to improvement of the failing heart

Question 32

what is the effect of d. glycosides in G.I tract?

Answer 32

1. Gut disturbance ( anorexia, salivation, diarrhea) 2. vomitting is due to irritation of the heart & effects of chemoreceptor trigger zone

Question 33

what is the effect of d. glycosides in CNS effect?

Answer 33

1. minor depression