Chapter 16

Question 1

Describe P wave, QRS complex, T wave, U wave

Answer 1

p wave = depolarization of muscle cells
QRS complex = depolarization of ventricular muscle cells
T wave = ventricular muscle repolarizes
u wave = not always seen, but follows T wave

Question 2

repolarization

Answer 2

myocardial muscle cells relax

Question 3

what is the sodium potassium ion pump?

Answer 3

when a cell is stimulated, movement of ions in and out of the membrane alters its charge, reversing resting potential

Question 4

fibrillation

Answer 4

quivering contraction of cardiac muscle fibers

Question 5

automaticity

Answer 5

cardiac cell membranes spontaneously depolarize at recurrent periods

Question 6

cardiac cycle

Answer 6

events that occur from the beginning of one ventricular contraction (systole) until the beginning of another

Question 7

what are the five steps in the analysis of an ECG?

Answer 7

is rhythm regular?
are all QRS’s similar?
Are all P waves similar?
is rate normal?
do waves and complexes proceed in normal sequence?

Question 8

what are unique features to the tissue of the cardiac neural conductive system?

Answer 8

allows cell membranes to spontaneously depolarize
cell membranes are in direct contact with cardiac muscle, and action potential initiaes depolarization

Question 9

cardiac output

Answer 9

amount of blood ejected from the ventricles each minute

Question 10

depolarization

Answer 10

myocardial cells are stimulated to contract

Question 11

what indicates an AV block?

Answer 11

longer intervals indicate that the impulse is being delayed from entering the ventricles

Question 12

what are the classic events required for a normal cardiac cycle?

Answer 12

rhythmic contraction and relaxation of the chambers of the heart, atria, and the ventricles

Question 13

what is one of the most common cardiac arrhythmias?

Answer 13

atrial fibrillation

Question 14

what happens when the QRS complex is wide?

Answer 14

an extra impulse is fired, PVC

Question 15

what are the two principal cell types of the heart and examples?

Answer 15

working cardiac cells (cardiac muscle, myocardium of atria and ventricles)
specialized neural conductive (SA node, AV node, bundle of HIS, purkinjie fibers)

Question 16

action potenial

Answer 16

process of depolarization and repolarization of the cardiac membrane

Question 17

what is known as the pacemaker of the heart?

Answer 17

SA node

Question 18

what is the purpose of the heart?

Answer 18

to pump blood through vessels to vital organs and tissues

Question 19

what is the baseline of an ECG called?

Answer 19

isoelectric line

Question 20

what are deflections in an ECG?

Answer 20

positive/negative changes in the tracing relative to the isocenter over the time of the cycle

Question 21

arrhythmia

Answer 21

irregularity of cardiac actions associated with physiologic or pathologic interruption of the neuro conductive tissues of the heart

Question 22

assessment of the hearts ability to perform its vital function is possible using what?

Answer 22

electrocardiogram

Question 23

asystole

Answer 23

no evidence of any cardiac neuro conductive activity (cardiac arrest)

Question 24

how is ventricular fibrillation seen on an ECG?

Answer 24

twitch and quiver