Hsf: The Electrocardiogram

Front 1

2 Pumps of Heart and Functions

Back 1

-Right Side: Pumps blood through the lungs
-Left Side: Squirts blood to the peripheral organs

Front 2

Function of Atrium

Back 2

-"Primer" for the ventricle

Front 3

Function of Ventricle

Back 3

-Supplies the main force to move the blood through the circulation

Front 4

Rhythmic electrical activity normally begins in the _____ ______ _____.

Back 4

-Sono-Atrial node (SA)

Front 5

Where is the SA located?

Back 5

-Superior wall of the right atrium near the opening of the superior vena cava

Front 6

What do action potentials generate in the SA node?

Back 6

-Excited electrical (action potential) activity in the atrial muscle which contract in response and inject blood into the ventricles

Front 7

The electrical activity initiated by the SA node excites the ______ _______ ______.

Back 7

-Atrioventricular node (AV)

Front 8

Where is the AV node located?

Back 8

-Posterior septal wall of the right atrium immediately being the tricupsid valve and and adjacent to the opening of the coronary sinus

Front 9

What gets excited after the AV node?

Back 9

-Purkinje fiber system

Front 10

Purkinje cells (def)

Back 10

-Specialized for rapid action potential conduction
-Serve to rapidly depolarize the inner wall of the ventricles

Front 11

2 Pumps of Heart and Functions

Back 11

-Right Side: Pumps blood through the lungs
-Left Side: Squirts blood to the peripheral organs

Front 12

Function of Atrium

Back 12

-"Primer" for the ventricle

Front 13

Function of Ventricle

Back 13

-Supplies the main force to move the blood through the circulation

Front 14

Rhythmic electrical activity normally begins in the _____ ______ _____.

Back 14

-Sono-Atrial node (SA)

Front 15

Where is the SA located?

Back 15

-Superior wall of the right atrium near the opening of the superior vena cava

Front 16

What do action potentials generate in the SA node?

Back 16

-Excited electrical (action potential) activity in the atrial muscle which contract in response and inject blood into the ventricles

Front 17

The electrical activity initiated by the SA node excites the ______ _______ ______.

Back 17

-Atrioventricular node (AV)

Front 18

Where is the AV node located?

Back 18

-Posterior septal wall of the right atrium immediately being the tricupsid valve and and adjacent to the opening of the coronary sinus

Front 19

What gets excited after the AV node?

Back 19

-Purkinje fiber system

Front 20

Purkinje cells (def)

Back 20

-Specialized for rapid action potential conduction
-Serve to rapidly depolarize the inner wall of the ventricles

Front 21

2 Pumps of Heart and Functions

Back 21

-Right Side: Pumps blood through the lungs
-Left Side: Squirts blood to the peripheral organs

Front 22

Function of Atrium

Back 22

-"Primer" for the ventricle

Front 23

Function of Ventricle

Back 23

-Supplies the main force to move the blood through the circulation

Front 24

Rhythmic electrical activity normally begins in the _____ ______ _____.

Back 24

-Sono-Atrial node (SA)

Front 25

Where is the SA located?

Back 25

-Superior wall of the right atrium near the opening of the superior vena cava

Front 26

What do action potentials generate in the SA node?

Back 26

-Excited electrical (action potential) activity in the atrial muscle which contract in response and inject blood into the ventricles

Front 27

The electrical activity initiated by the SA node excites the ______ _______ ______.

Back 27

-Atrioventricular node (AV)

Front 28

Where is the AV node located?

Back 28

-Posterior septal wall of the right atrium immediately being the tricupsid valve and and adjacent to the opening of the coronary sinus

Front 29

What gets excited after the AV node?

Back 29

-Purkinje fiber system

Front 30

Purkinje cells (def)

Back 30

-Specialized for rapid action potential conduction
-Serve to rapidly depolarize the inner wall of the ventricles

Front 31

What gets excited after the Purkinje cells?

Back 31

-Ventricular muscle (from the inner to the outside)

Front 32

What do the ventricular action potentials produce?

Back 32

-Coordinated contraction of the ventricles which facilitates the proper pumping of the blood through the circulation

Front 33

How do action potential spread through the various cardiac tissues>

Back 33

-By local circuit currents

Front 34

What does the EKG resemble?

Back 34

-a reflection of the electrical activity if the heart

Front 35

What kind of measurement is read by the EKG?

Back 35

-Voltage measurement (produced by current flow)

Front 36

Name of the two measuring points for an EKG

Back 36

-Leads

Front 37

3 Most Common Combinations for Leads

Back 37

-Lead I
-Lead II
-Lead III

Front 38

The positive deflections of the EKG represent _______ current dye ti action potentials spreading towad the positive lead of the EKG machine.

Back 38

-depolarizing

Front 39

Action potentials flowing away form the positive lead would produce a _______ deflection.

Back 39

-Downward

Front 40

3 Phases of Activity Associated with Heart Beat (EKG)

Back 40

1. P-wave
2. QRS complex
3. T-wave

Front 41

P-wave (def)

Back 41

-Voltage change induced by current flow through atrial muscle fibers during the action potential upstroke (depolarizing phase) in these cells

Front 42

QRS-Comples (def)

Back 42

-Voltage change induced by current flow through ventricular muscle fibers during the action potential upstroke (depolarizing phase) in these cells

Front 43

R wave is a _______ signal.

Back 43

-Large

Front 44

What contributes to the large size of an R wave in an EKG?

Back 44

-Rapid-conducting Purkinje fiber system assures the simultaneous initiation of ventricular muscle action potentials
-Synchronized, depolarizing currents flowing through so many ventricular muscle cells leads to a large signal

Front 45

Why are the Q and S components of the EKG sometimes not seen in patients?

Back 45

-Components of the action potential spread that are not toward the recording electrode (the left leg).

Front 46

T-wave (def)

Back 46

-Voltage change induced by current flow through the ventricular muscle fibers during the action potential repolarization in these cells

Front 47

T-wave is typically a signal ______ than the P-wave but ______ than the QRS-complex.

Back 47

-Larger
-Smaller

Front 48

Why is the T-wave a positive deflection?

Back 48

-Action potentials on the outer wall of the heart are of shorter duration than those of the inside

Front 49

The outer part of the ventricles is the ____ to depolarize but the ______ to repolarize.

Back 49

-Last
-First

Front 50

T-wave is a wave of repolarization spreading ____ form the positive recording electrode.

Back 50

-Away

Front 51

What parts of the EKG's T-wave have important diagnostic meaning?

Back 51

-Size
-Shape
-Direction

Front 52

Parts of Heart that no EKG signals are recorded?

Back 52

-Purkinje fibers
-Nodal tissues

Front 53

Heart rate: Below and Above normal

Back 53

-Below 60/min=Slower than norm=Bradycardia
-Above 100/min=too fast=tachycardia

Front 54

Range for Normal Heart Rate

Back 54

-50-90 beats/min

Front 55

Normal values for P-R interval

Back 55

0.12 and 0.2 sec

Front 56

Normal QRS complex
-What if its largeer

Back 56

0.1 sec of less
-Longer= problems with AP conduction in ventricles

Front 57

Q-T interval

Back 57

-0.44 sec or less
-Longer= problems with ventricular muscle repolarization and could lead to potentially fatal arrhythmias