Chapter 28

Question 1

describe the cardiac conduction system

Answer 1

controls the rate and direction of electrical impulse conduction in the heart

Question 2

impulses are generated in the

Answer 2

SA node

Question 3

the conduction system maintains

Answer 3

pumping efficiency of the heart

Question 4

cardiac action potential:

describe phase 4

Answer 4

repolarization or the resting piece. starting to build up the action potential. this is where the sodium and potassium pump take place.

Question 5

cardiac action potential :

phase 0:

Answer 5

calcium and sodium channels open. and rapid depolarization happens. squeeze

Question 6

cardiac action potential:

phase 1:

Answer 6

early repolarization. can’t have another heart beat bc ventricular are contracting and don’t have enough to beat again

Question 7

cardiac action potential:

phase 2:

Answer 7

plateau phase. calcium flowing inward. ions are starting to move. not

Question 8

cardiac action potential:

phase 3:

Answer 8

rapid final repolarization and down slope of action potential. K+ is very important here

Question 9

refractory periods:

No stimuli can generate another action potential. Includes phase 0, 1, 2, and part of 3. The cell can’t depolarize again

Answer 9

absolute refractroy period

Question 10

refractory periods:

greater than normal stimulus response. repolarization returns the membrane potential to below the threshold (although not yet at the resting membrane potential). begins when the transmembrane potential in phase 3 reaches the threshold potential level. ends just before the terminal portion of phase 3

Answer 10

relative refractory period

Question 11

refractory periods:

a weak stimulus can evoke a response. extends from the terminal portion portion of phase 3 until the begin of phase 4. cardiac arrthymias develop.

Answer 11

supernormal excitatory period

Question 12

sum of all cardiac action potentials

Answer 12

electrocardiogram

Question 13

EKG:

atrial depolarization

Answer 13

P wave

Question 14

EKG:

time from the onset of atrial activation to the onset of ventricular activation

Answer 14

PR interval

Question 15

EKG:

sum of all ventricular depolarization

Answer 15

QRS complex

Question 16

EKG:

repolarization phase of ventricles

Answer 16

T wave

Question 17

how many leads are used for a EKG?

Answer 17

12 leads

Question 18

a diagnostic EKG provides a

Answer 18

unique view of the electrial forces of the heart

Question 19

your patient has an EKG that has sawtooth patter P waves. what type of atrial arrhytmia is this?

Answer 19

atrial flutter

Question 20

what is the goal of atrial flutter?

Answer 20

control the rate ventricles fire or stop atria from rapid fire.

Question 21

what is the risk of atrial flutter?

Answer 21

clot formation in the atria

Question 22

your patient has an EKG with rapid, disorganized contraction of the atria and unrecognizeable P waves. the atrial rate is 500 BPM. what type of atrial arrhytmia are they having?

Answer 22

atrial fibrillation

Question 23

what is the goal of atrial fibrillation?

Answer 23

slow the ventricular rate or stop atria from rapid fire

Question 24

what is the risk of atrial fibrillation?

Answer 24

clot formation in the atria

Question 25

you are monitoring a beside cardiac monitor… what should you look for?

Answer 25

identification of ST segment changes, advanced arrhythmia identification, diagnose and provide treatment