Module 15 pt 2 Heart Physioology Flashcards

1
Q

This system is a network of non-contractile cells that initiate and distribute impulses to coordinate the depolarization and contraction of the heart

A

Intrinsic cardiac conduction system

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2
Q

These cells have a unstable resting potential due to the open slow Na+ channels, they continuously depolarize

A

Autorhythmic cells

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3
Q

These autorhythmic cells are found in certain areas of the heart, including this node that is considered the pacemaker of the heart

A

Sinoatrial node

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4
Q

How often does the SA node beat and what is the rhythm called?

A

90-95 times per minute, it is called the sinus rhythm

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5
Q

What is unique about the SA node?

A

It depolarizes faster than any other part of the myocardium

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6
Q

This node has fewer gap junctions and has a .1 second delay

A

Atrioventricular Node

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7
Q

What is the reason for the .1 second pause of the AV node?

A

If there was no pause, the heart would be pumping blood against itself instead of through the valves

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8
Q

This is the only electrical connection between the atria and the ventricles

A

AV bundle, or the bundle of HIS

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9
Q

These are two pathways in the interverticular septum that carry the impulses towards the apex of the heart

A

Right and Left bundle branches

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10
Q

This is the complete pathway into the apex and ventricular walls

A

Purkinje Fibers

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11
Q

Irregular heart rhythms where there are uncoordinated atrial and ventricular contractions

A

Arrhythmias

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12
Q

This is a homeostatic imbalances that is a rapid irregular contraction, useless for pumping blood

A

Fibrillation

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13
Q

A defective node may result in an abnormal pacemaker takes over, like the AV node (40-60 bpm)

A

Ectopic Focus

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14
Q

A defective SA node might result in a few or no impulses from the SA actually reach the ventricles

A

Partial or total heart block

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15
Q

What is the heartbeat modified by?

A

Autonomic Nervous System

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16
Q

Where are the cardiac systems located in the brain?

A

Medulla oblongata

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17
Q

What does the Cardioinhibitory center inhibit and what through?

A

The SA and AV nodes through the vagus nerve

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18
Q

This is a composite of all the action potentials generated by nodal and contractile cells at a given time

A

Electrocardiogram

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19
Q

This is a wave in the ECG that shows the depolarization of the SA node

A

P wave

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20
Q

This is a wave in the ECG that shows the ventricular depolarization

A

QRS complex

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21
Q

This is a wave in the ECG that shows ventricular repolarization

A

T wave

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22
Q

How many sounds are there associated with closing heart valves?

A

Two

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23
Q

What does the first sound of the heart pertain to?

A

AV valve closes and begins systole

24
Q

The second sounds occurs when the heart does what?

A

The SL valves close at the beginning of ventricular disatole

25
Q

This is an abnormal heart sound that occurs most often indicative valve problems normally in the mitral valve

A

Heart Murmurs

26
Q

This includes all events associated with blood flow through the heart during on complete heart beat

A

Cardiac cycle

27
Q

What is the term used when the heart is contracting?

A

Systole

28
Q

What is the term used when the heart is relaxing?

A

Diastole

29
Q

In the phases of the Cardiac cycle, this is the first step when the AV valves are open and this happens mid-late diastole

A

Ventricular Filling

30
Q

After the AV valves open during ventricular filling, what happens that delivers the leftover 20% of blood remaining?

A

Atrial Systole

31
Q

This is the volume of the blood in each ventricle at the end of ventricular diastole

A

End-Diastolic volume

32
Q

This is the second phase of the Cardiac cycle when the atria and the ventricles begin to contract, rising pressure results in the closing of AV valves

A

Ventricular Systole

33
Q

This is the phase of the cardiac cycle when all of the valves are closed

A

Isovolumetric contraction

34
Q

In this phase, ventricular pressure exceeds pressure in large arteries forcing the SL valves open

A

Ejection phase

35
Q

This is a term that is the volume of blood remaining in each ventricle

A

End-systolic volume

36
Q

This is the final phase of the cardiac cycle that occurs in early diastole that is when ventricles relax

A

Isovolumetric relaxation

37
Q

This is the backflow of blood in the aorta and pulmonary trunk closes SL valve and causes this

A

Dicrotic Notch

38
Q

This is the volume of blood pumped by each ventricle in one minute

A

Cardiac Output

39
Q

What is the equation for cardiac output?

A

Heart rate X Stroke Volume

40
Q

What does the term cardiac reserve mean?

A

The difference between resting and maximal CO

41
Q

What are the three main factors that affect SV?

A

Preload
Contractillity
Afterload

42
Q

What does stroke volume equal?

A

End-diastolic volume minus End-systolic volume

43
Q

This is a regulation of stroke volume that is the degree os stretch of cardiac muscle cells before they contract

A

Preload

or Frank-Starling law of the heart

44
Q

This is a regulation of stroke volume when contractile strength at a given muscle length is independent of muscle stretch and EDV

A

Contractility

45
Q

This is an increase contractility which is an increase of calcium

A

Positive inotropic agents

46
Q

This is the decrease of contractility which is when calcium channels are blocked

A

Negative inotropic agents

47
Q

This is a regulation of stroke volume, the pressure that has to be overcome for ventricles to eject blood

A

Afterload

48
Q

What increases the regulation of heart rate

A

Positive chronotropic factors

49
Q

What decreases the increase of heart rate

A

Negative Chronotropic factors

50
Q

What is activated by emotional or physical stressors

A

Sympathetic nervous system

51
Q

What part of the nervous system opposes sympathetic effects

A

Parasympathetic system

52
Q

This is a sympathetic reflex initiated by increased venous return

A

Atrial reflex

53
Q

What hormone from the adrenal medulla enhances heart rate and contractility?

A

Epinephrine

54
Q

This is an abnormally fast heart rate that if persistent can lead to fibrillation

A

Tachycardia

55
Q

This is when the heart rate s slower than 60 bpm that can cause grossly inadequate blood circulation

A

Bradycardia

56
Q

This is a progressive condition where the CO is so low that blood circulation is inadequate to meet tissue needs

A

Congestive Heart Failure