Chapter 2

Question 1

Polarized

Answer 1

negatively charged resting cardiac cell

Question 2

Depolarization

Answer 2

discharge of electricity - occurs when cardiac cell becomes positively charged

Question 3

Repolarization

Answer 3

return of the cardiac cell to its resting negative charge

Question 4

Electrical events

Answer 4

Depolarization and Repolarization

Question 5

Mechanical

Answer 5

contraction and relaxation

Question 6

Action Potential

Answer 6

what happens to cardiac cell when stimulated by electrical charge

Question 7

Action Potential - Phase 4

Answer 7

cardiac cell at rest. Corresponds with isoelectric line of EKG

Question 8

Action Potential - Phase 0

Answer 8

depolarization. Cell becomes positively charged. Corresponds with QRS complex on EKG

Question 9

Action Potential - Phase 1 and 2

Answer 9

early repolarization. calcium is released. muscle contraction begins. Corresponds with ST segment of EKG

Question 10

Refractory Periods

Answer 10

cardiac cell cannot responding to/depolarizing from an impulse

Question 11

Refractory Periods - Absolute refractory period

Answer 11

cardiac cell cannot respond to another impulse, no matter how strong

Question 12

Refractory Periods - Relative refractory period

Answer 12

cell can respond only to very strong impulse

Question 13

Refractory Periods - supernormal period

Answer 13

cardiac cell is “hyper” will respond to very weak stimulus

Question 14

P-QRS-T represents

Answer 14

one heartbeat

Question 15

P wave

Answer 15

Atrial depolarization

Question 16

Ta wave

Answer 16

atrial repolarization

Question 17

QRS

Answer 17

a series of spiky waves; ventricular depolarization

Question 18

T wave

Answer 18

ventricular repolarization

Question 19

U wave

Answer 19

late ventricular repolarization

Question 20

PR segment

Answer 20

flat line between the P wave and the QRS complex

Question 21

ST segment

Answer 21

flat line between the QRS complex and the T wave

Question 22

Q wave

Answer 22

negative wave that precedes an R wave in the QRS complex

Question 23

R wave

Answer 23

any positive wave in the QRS complex

Question 24

S wave

Answer 24

negative wave that follows an R wave

Question 25

Cardiac Conduction System

Answer 25

pathway of specialized cells - job is to create and conduct impulses to tell the heart when to beat

Question 26

Conduction pathway

Answer 26

sinus node>interatrial tracts>atrium>internodal tracts>AV node>bundle of His>bundle of branches>perkinje fibers>ventricle

Question 27

Cardiac cells - automaticity

Answer 27

electrical - ability to create an impulse

Question 28

Cardiac cells - Conductivity

Answer 28

electrical - ability to pass that impulse along to neighboring cells

Question 29

Cardiac cells - Excitability

Answer 29

electrical - ability to respond to that impulse by depolarizing

Question 30

Cardiac cells - Contractility

Answer 30

mechanical - ability to contract and do work

Question 31

Sinus node rate

Answer 31

60-100

Question 32

AV junction

Answer 32

40-60

Question 33

Ventricle

Answer 33

20-40

Question 34

Escape

Answer 34

predominant pacemaker slows down

Question 35

Escape beat

Answer 35

beat that comes in after a pause longer than the normal R-R interval

Question 36

Usurpation

Answer 36

lower pacemaker becomes hyper

Question 37

Arrhythmia

Answer 37

abnormal heart rhythm

Question 38

One small block =

Answer 38

0.04 secs

Question 39

One big block =

Answer 39

0.20 secs

Question 40

Intervals

Answer 40

measurements of time between EKG waves and complexes

Question 41

PR interval

Answer 41

beginning of P wave to beginning of QRS wave; 0.12-0.20 secs

Question 42

QRS interval

Answer 42

beginning of QRS wave to end of QRS wave; 0.12 secs