chapter 9

Question 1

Action potential:

Answer 1

an electrical impulse that stimulates cardiac muscle contraction

Question 2

Arrythmia:

Answer 2

a disturbance or irregularity in the heart rate or rhythm

Question 3

Blockage effect:

Answer 3

the action of antiarrhythmic drugs by blocking stimulation of β-receptors of the heart by adrenergic neurohormones

Question 4

Cinchonism:

Answer 4

a term for quinidine toxicity

Question 5

Depolarization:

Answer 5

the movement of a stimulus passing along the nerve, the positive ions move into the cell

Question 6

Polarization:

Answer 6

a point at which the positive ions on the outside are equal to the negative ions on the inside of the cell

Question 7

Proarrhythmic effect:

Answer 7

the development of a new arrhythmia or worsening of an already existing arrhythmia by administering an antiarrhythmic drug

Question 8

Refractory period:

Answer 8

the period between transition of the nerve impulse along a nerve fiber

Question 9

Repolarization:

Answer 9

the movement back of the ions to its original state after the impulse passes.

Question 10

Threshold:

Answer 10

is the lowest intensity stimulus that will cause response

Question 11

Atrial flutter:

Answer 11

rapid contraction of the atria more than 300 b/min

Question 12

Atrial fibrillation:

Answer 12

irregular an rapid atrial contraction

Question 13

Premature ventricular contractions:

Answer 13

beats originates in the ventricles instead of the SA-node, causing the ventricles to contract before the atria

Question 14

Ventricular tachycardia:

Answer 14

rapid heart beat more than 100 beat/min

Question 15

Ventricular fibrillation:

Answer 15

rapid disorganized contractions of the ventricles resulting in inability of the heart to pump blood, leading to death

Question 16

Polarization

Answer 16

A state of a nerve cell with positive ions on the outside and negative ions on the inside

Question 17

Depolarization

Answer 17

When the ions are moving around

Question 18

Repolarization

Answer 18

When the ions are back in place

Question 19

Class I

Answer 19

Membrane-stabilizing or anesthetic effect on the cells of the myocardium

Question 20

Class II

Answer 20

decrease the myocardial response to epinephrine and nor epinephrine

Question 21

Class III:

Answer 21

they prolong the refractory period

Question 22

Action potential

Answer 22

Electrical impulse passing from cell to cell in the heart muscle

Question 23

Refractory period

Answer 23

Period between the transmission of nerve impulses along a nerve fiber

Question 24

Class I-A▪Action:

Answer 24

Depresses myocardial excitability

Question 25

Class I-B•Action

Answer 25

Raises the threshold in the ventricular myocardium

Question 26

Class I-C▪Action:

Answer 26

Decreases the height and rate of rise of cardiac action potentials

Question 27

Uses of Antiarrhythmic Drugs

Answer 27

Used to prevent and treat cardiac arrhythmias