Electrical Activity Of Heart Part 1

Question 1

What are cells that are specialized cardiac muscle cells that have the property of depolarizing spontaneously toward the threshold for the formation of action potentials?

Answer 1

Pacemaker cells

Question 2

Pacemaker cells can _______________ depolarizing and repolarizing

Answer 2

Spontaneously

Question 3

What pacemaker cell is found in the arterial wall, near where the venae cavae enter the right atrium?

Answer 3

SA pacemaker cells

Question 4

Which pacemaker cells is found in normal healthy heart, where action potentials come from- physiological pacemaker?

Answer 4

SA node

Question 5

Which pacemaker cells have a slower conduction velocity and longer refractory period compared to SA node pacemaker cells?

Answer 5

AV

Question 6

What pacemaker cell is the only conducting pathway between atria and ventricles?

Answer 6

AV

Question 7

Action potentials produced in ___ node propagate to the entire heart through a specialized conducing system

Answer 7

SA

Question 8

Which node prevents action proteins that reach the ventricles from “circling back” and reactivating the atria?

Answer 8

AV node

Question 9

Which bundle contains Purkinje fibers?

Answer 9

AV bundle

Question 10

The spontaneous depolarization of SA node pacemaker cells, the heart initiates its muscle action potentials and contractions ______ motor neurons

Answer 10

Without

Question 11

In a normal hear beat, both ____ contract, almost simultaneously

Answer 11

Atria

Question 12

Which pacemakers are slow and one way conducting?

Answer 12

Ectopic

Question 13

Which pacemakers have abnormal myocardium?

Answer 13

Ectopic

Question 14

What can cause reentrant arrhythmias?

Answer 14

Circus movement from ectopic pacemaker cells

Question 15

What is the spontaneous depolarization called?

Answer 15

Pacemaker potential