KNR 353 - Chapter 1

Question 1

Automaticity

Answer 1

the unique ability of cardiac pacemaker cells to initiate spontaneous excitation impulses

Question 2

Depolarization

Answer 2

the electrical process of discharging polarized cells, usually resulting in muscle contraction

Question 3

Repolarization

Answer 3

the process of recharging depolarized cells back to their “ready” (polarized) state

Question 4

Conduction system

Answer 4

the pathways of conductive tissues within the heart that facilitate passage of electrical impulses throughout the myocardium

Question 5

AV junction

Answer 5

that part of the cardiac conduction system that connects the atria and the ventricles; contains the AV node and the non-branching part of the Bundle of His

Question 6

Escape

Answer 6

the mechanism that allows a lower pacemaker site to assume pacemaking responsibilities when a higher site fails

Question 6

Arrhymthia

Answer 6

the graphic representation of the heart’s electrical activity; the term is loosely used to mean an abnormality of the heart’s electrical function, but it is also used to categorize patterns of electrical activity, not all of which are necessarily abnormal or bad; also called dysrhythmia; it can also be used to mean that a rhythm is not regular

Question 7

Dysrhythmia

Answer 7

arrhythmia