20.1-20.5

Question 1

Pathway of the Cardiac Action Potential

Answer 1

Sinoatrial node, atrioventricular node, atrioventricular bundle, right and left branches, purkinje fibers

Question 2

Radiate action potential upside the heart

Answer 2

Purkinje Fibers

Question 3

100BPM; main pacemaker of the heart

Answer 3

Sinoatrial node

Question 4

Cardiac Action Potential

Answer 4

Depolarization, Plateau, Repolarization

Question 5

Open voltage-gated Na channels; leaky potassium channels. -90mv

Answer 5

Depolarization (first step of cardiac Action Potential

Question 6

Caused by calcium inflow, slow Ca channels opening and K is released out when K channels open

Answer 6

Plateau (second step of cardiac action potential)

Question 7

Closure of Ca channels and K outflow when additional K channels open

Answer 7

Repolarization (last step of cardiac Action potential)

Question 8

Recording of electrical signals; Composite record of Action potentials produced by all of the heart muscle fibers during each heart beat

Answer 8

Electrocardiogram ECG

Question 9

Represents atrial depolarization, which spreads from the SA node through contractive fibers in both atria

Answer 9

P Wave

Question 10

Where a controlled contraction begins; systole

Answer 10

PR Interval

Question 11

Delay between SA node and AV node

Answer 11

PQ interval

Question 12

Represents rapid ventricular depolarization; precedes contraction

Answer 12

QRS complex

Question 13

When ventricular contraction happens

Answer 13

S-T segment

Question 14

Ventricular Repolarization, causing relaxation

Answer 14

T wave

Question 15

Degree of stretch on the heart before it contracts

Answer 15

Preload

Question 16

Forcefulness of contraction of individual ventricular muscle fibers

Answer 16

Contractility

Question 17

Pressure that must be exceeded before ejection of blood from the ventricles can occur

Answer 17

Afterload

Question 18

Phase of contraction

Answer 18

Systole

Question 19

Phase of relaxation

Answer 19

Diastole

Question 20

Heart sound when tri and bi closes

Answer 20

S1

Question 21

Heart sound when Aortic valve closes

Answer 21

S2

Question 22

How much blood leaves the heart each minute

Answer 22

Cardiac Output

Question 23

Difffence between maximum cardiac output and cardiac output at rest

Answer 23

Cardiac reserve

Question 24

More stretch, more contraction

Answer 24

Frank-Starling Law of the Heart

Question 25

Longer time to stretch and fill, more contraction

Answer 25

Duration of ventricular diastole

Question 26

Rate of blood flow back to the heart

Answer 26

Venous return

Question 27

Increase contractility; sympathetic

Answer 27

Positive inotropic agents

Question 28

Decrease contractility; parasympathetic

Answer 28

Negative inotropic agents

Question 29

Monitor movements

Answer 29

Proprioceptors

Question 30

Monitor blood chemistry

Answer 30

Chemoreceptors

Question 31

Monitor blood pressure

Answer 31

Baroreceptors