Chapter 28 Online Quiz

Front 1

The intrinsic firing rate of the AV node is ___ to ___ times per minute.

Back 1

40, 60

Front 2

The thick middle tissue layer of the heart is the

Back 2

myocardium

Front 3

Slowing of the electrical impulse at the AV node is necessary to allow time for the _______ to fill with blood

Back 3

ventricles

Front 4

The mitral valve is also known as the _______ valve

Back 4

L atrioventricular

Front 5

Which of the following describes the ability of a cardiac cell to propagate the electrical impulse to another cell

Back 5

Conductivity

Front 6

The pressure in the left ventricle at the end of diastole is called

Back 6

preload

Front 7

An action potential begins in a myocardial cell when

Back 7

sodium enters the cell, giving it a positive charge

Front 8

the total duration of ventricular depolarization is represented by the ___ interval.

Back 8

QT

Front 9

The SA and AV nodes are often supplied by both the _____ and ______ arteries

Back 9

R coronary, circumflex coronary

Front 10

Which of the following is the correct sequence of cardiac electrical activity

Back 10

4,2,1,3,6,5

Front 11

The amount of resistance that must be overcome by the left ventricle during systole is called

Back 11

afterload

Front 12

Approx ______ Americans die each year of CHD

Back 12

466,000

Front 13

At standard speed, a 1mm box on ECG paper represents _____ seconds

Back 13

.04

Front 14

The relative refractory period of the myocardium is represented by the

Back 14

down slope of the T wave

Front 15

Which of the following arteries supplies blood to the left ventricle, interventricular septum, and portions of the cardiac conduction system

Back 15

left coronary