Unit One Flashcards

1
Q

What is the supply and demand concept of the heart

A

Cells demand O2 and nutrients, the CV system supply blood to cells

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2
Q

Blood flow occurs when what exists

A

Change in pressure, one pressure exceeds the other

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3
Q

What does every cell need for survival

A

Oxygen, nutrients, removal of CO2 and metabolic waste, optimal temperature

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4
Q

Oxygen is needed by the cell for what

A

Aerobic respiration

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5
Q

Nutrients are needed by the cell for what

A

Energy, building blocks, etc

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6
Q

Carbon dioxide retention causes

A

Acidosis leading to confusion, come, arrhythmia, muscle weakness, GI disturbances

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7
Q

Urea and other metabolic wastes left in blood causes

A

Anorexia, lethary, decreased mental acuity and coma, nausea, vomiting, bone pain, itch, SOB, seizures and death

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8
Q

Why do our cells need optimal temperature

A

Function at a narrow temperature range

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9
Q

Can demands be met by just diffusion from the outside of the body

A

No, diffusion is too slow over large distances

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10
Q

It takes how long for O2 to diffuse 100 micrometers

A

5 seconds

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11
Q

How long for O2 to diffuse 1 cm

A

14 hours

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12
Q

Main purpose of the cardiovascular system

A

Provide a sufficiently fast mechanism of delivery and removal of gasses, nutrients, and wastes by blood flow

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13
Q

Diffusion is important at what levels of the body

A

Capillaries, interstitial fluid and cell membranes

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14
Q

What is a blood conditioner organ

A

Any organ that changes the composition of the blood for the benefit of the rest of the body

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15
Q

What organs are blood conditioner organs

A

Lungs, kidneys, GI tract and skin

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16
Q

What two things do all blood conditioner organs have in common

A

Blood flow in excess of their basic metabolic needs, can tolerate substantial drops in blood flow for a short period of time

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17
Q

What are some organs that are important but not blood conditioners

A

Brain, muscle and heart

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18
Q

What are the characteristics of brain, muscle and heart not being blood conditioners

A

Blood flow is regulated to be at or just above metabolic need, loss of blood flow to these organs has more dramatic effect

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19
Q

The systemic circuit goes from where to where

A

Left ventricle, body, right atrium

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20
Q

The pulmonary circuit goes from where to where

A

Right ventricle, lungs to left atrium

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21
Q

The systemic and pulmonary circuit are parallel or series

A

Series

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22
Q

Function of systemic circuit

A

Supplies many organs, trunk, head and limbs in parallel circulation

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23
Q

Is the systemic circuit parallel or series

A

Parallel

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24
Q

What are the three places within the systemic circuit that has serial blood supply

A

Liver, kidney and anterior pituitary

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25
Q

Advantage of parallel circuit

A

If something is blocked then there are other ways around to have area receive blood, simultaneous blood supply

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26
Q

What is the basic flow equation

A

= change in pressure/ resistance to flow

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27
Q

Basic flow equation AKA

A

Ohm’s law

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28
Q

Flow (volume per unit time) represented by what

A

Q

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29
Q

What is the equation for resistance

A

8Ln/(pi)r^4

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30
Q

What is cardiac output

A

Blood from the heart

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31
Q

Flow (Q) is also called

A

Cardiac output

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32
Q

Normal cardiac output is

A

5 L/min

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33
Q

What is the source of blood flow

A

Heart

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34
Q

What must the heart do in order for flow to occur

A

Arterial pressure greater than venous pressure

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35
Q

How does resistance of blood flow occur

A

Frictions,

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36
Q

What is the main determinant of resistance

A

Blood vessel radius especially in arteriole

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37
Q

Why is the blood vessel radius in arterioles the most important

A

Radius is regulated the most here

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38
Q

The left ventricle has an average pressure of what

A

100 mmHg

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39
Q

Radius changes within vessels due to

A

Smooth muscle, dilation and constriction

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40
Q

How does the venous system work with pressure and bringing blood to heart

A

Pressure still builds up but not greater than arterial pressure and veins contain valves

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41
Q

Because blood flows along the path of least resistance, organs with ???? Resistance receives the ???? Flow.

A

Low, most

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42
Q

Constriction in vessels cause

A

Diversion to another place

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43
Q

What are the requirements for effective heart function

A

Synchronized contraction of heart muscle, valves open fully, no leaky valves, contractions adequately strong, ventricles fill adequately

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44
Q

What are the parts of the left heart

A

Left atrium, bicuspid/ mitral valve, left ventricle and aortic valve, pulmonary veins

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45
Q

Function of left heart

A

Receives blood from lungs and pumps blood to body

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46
Q

Parts of the right heart

A

IVC, SVC, coronary sinus, right atrium, tricuspid valve, right ventricle, pulmonary valve

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47
Q

Functions of the right heart

A

Receives blood from the body, pumps blood to the lungs

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48
Q

Describe cardiac cells

A

Single centrally located nucleus, branched fibers, striated, intercalated discs

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49
Q

What connects the adjacent cells in the cardiac muscle

A

Gap junctions

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50
Q

Gap junctions form what between cells

A

Electrical synapses

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51
Q

Atrial and ventricular syncytia are separated by what

A

Fibrous septum

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52
Q

The fibrous septum surrounds what

A

Openings of the two AV valves.

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53
Q

What are not propagated through the fibrous septum

A

Action potentials

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54
Q

Aka of hyperpolarization

A

Undershoot

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55
Q

Is a stimulus needed for cardiac cells to have an AP

A

No

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56
Q

Cardiac muscle cells exhibit what two properties

A

Automaticity and rhythmicity

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57
Q

What is automaticity

A

Cells generate their own action potentials without external stimuli from nerves or chemicals

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58
Q

What is rhythmicity

A

Action potentials repeat at regular intervals

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59
Q

What cardiac muscle tissue has the fastest inherent firing rate

A

SA node

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60
Q

SA node AKA

A

Pacemaker

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61
Q

SA node connects with conduction system and what to control the rate of the whole heart

A

Intercalated discs

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62
Q

SA node embedded where

A

Wall of RA

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63
Q

Conduction system is made of

A

Specialized cardiac muscle cells

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64
Q

Amount of actin and myosin in the conduction system

A

Very little and contracts very weakly

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65
Q

Conduction system coordinates what

A

Timing of atrial and ventricular contractions

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66
Q

Communication between the atria and ventricles is done through

A

Bundle of His

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67
Q

Function of internodal tract

A

Spread AP to AV node, spread AP into both atria, help to spread AP throughout cells

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68
Q

What does the signal move slowly through AV node

A

Allow for ventricle to fill with blood

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69
Q

How many phases of the heart

A

Phase 0 through 4

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70
Q

What is phase 0 aka

A

Depolarization

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71
Q

What occurs during phase 0

A

Opening of fast V gated Na+ channels

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72
Q

Aka of phase 1

A

Initial spike

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73
Q

What occurs during phase 1

A

V gated Na+ channels inactive

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74
Q

Phase 2 aka

A

Plateau

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75
Q

What occurs during phase 2

A

V gated slow Ca2+ channels open and decrease in K+ permeability also occurs

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76
Q

Phase 3 aka

A

Repolarization

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77
Q

What occurs during phase 3

A

V gated Ca2+ channels close and V gated K+ channels open

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78
Q

Aka of phase 4

A

Resting membrane potential

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79
Q

What occurs during phase 4

A

Active transport of Na+, K+ and Ca2+

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80
Q

Describe the SR of cardiac cells

A

Not well developed

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81
Q

Describe T tubules of cardiac cells

A

5x bigger in diameter

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82
Q

Cardiac cells greatly depend on what for initiation and strength of contraction

A

Extracellular Ca2+ for initiation and strength of contraction

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83
Q

Relaxation of heart requires what

A

Pumping Ca2+ back into SR and out of the cell

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84
Q

The duration of cardiac contraction is about equal to

A

Duration of the cardiac action potential

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85
Q

Why is the cardiac contraction equal to duration of AP

A

Want the contraction long enough to empty atrium or ventricle, helps to not spend extra energy

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86
Q

Definition of cardiac cycle

A

All events occurring in the heart from the beginning of one heart beat to the beginning of the next

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87
Q

Definition of pressure

A

The magnitude of the force F exerted by a fluid on the surface, divided by the surface area A

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88
Q

Fluid moves from an area of

A

High pressure to an area of low pressure

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89
Q

The chambers of the heart alternate between periods of

A

Systole and diastole

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90
Q

Systole aka

A

Contraction

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91
Q

Purpose of systole

A

Generate pressure to perform the work of moving blood

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92
Q

Diastole aka

A

Relaxation

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93
Q

Purpose of diastole

A

Release pressure so that the heart chamber can fill with blood

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94
Q

The cardiac cycle components relating to pressure changes are recorded from the

A

Left atrium and ventricle

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95
Q

The right cardiac cycle looks essentially the same, except the pressures are about what compared to the left

A

1/6

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96
Q

What are the primer pumps

A

Atria

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97
Q

How much of the blood in the atria moves to the ventricles before atrial systole

A

80%

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98
Q

How much of the blood moves to the ventricles from the atria during atrial systole

A

20%

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99
Q

What happens if the atria fail to function

A

Lower cardiac output, clot formation

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100
Q

When atria contract what relaxes

A

Ventricles

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101
Q

What are the three atrial pressure curves

A

A, C and V curve

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102
Q

What occurs during the A curve

A

Increase in pressure due to contraction (atrial systole)

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103
Q

What occurs during the C curve

A

Fluctuation in pressure due to AV valve closure

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104
Q

What occurs during the V curve

A

Increase in pressure as atrium fills

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105
Q

What happens to pressure in ventricle during diastole

A

Decreases

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106
Q

What occurs during isovolumic relaxation

A

Pressure in ventricle decreases, valve can now close, diastole

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107
Q

Ventricle diastole has how many phases

A

Three, early, middle and late

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108
Q

What occurs to ventricle during early diastole

A

Blood enters ventricle, rapid inflow

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109
Q

What occurs to ventricle during middle diastole

A

Diastasis, reduced inflow

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110
Q

What occurs to ventricle during late diastole

A

Last 20% of blood comes in, atrial systole

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111
Q

What is isovolumic contraction

A

Pressure in ventricle not greater than pressure on other side of valve

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112
Q

Ventricular systole has how many phases

A

2, early and late

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113
Q

What occurs in ventricle during early systole

A

Rapid ejection

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114
Q

What occurs to ventricle during late systole

A

Reduced ejection

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115
Q

Does end systole in ventricle completely empty all blood

A

No

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116
Q

What is end diastolic volume

A

Amount of blood volume in ventricle at end of diastole

117
Q

What is end systolic volume

A

Amount of blood volume in ventricle at end of systole

118
Q

What is stroke volume

A

Amount of blood ventricle ejects after one contraction

119
Q

Equation for stroke volume

A

End diastolic volume - end systolic volume

120
Q

What is ejection fraction

A

Amount of blood percent squeezed out at end of contraction

121
Q

Equation for ejection fraction

A

Strok volume/ end diastolic volume x 100

122
Q

Ejection fraction should be around what percent

A

60%

123
Q

Equation for cardiac output

A

Stroke volume x heart rate

124
Q

During exercise, how to increase cardiac output

A

Increase heart rate or increase stroke volume or both

125
Q

Why does HR at 180 stop increasing CO

A

Not having enough time for diastole, or need ventricles to fill

126
Q

When do AV valve close

A

Ventricular pressure greater than atrial pressure

127
Q

AV valves open when

A

Atrial pressure greater than ventricular pressure

128
Q

What prevents prolapse into the atria of AV valve

A

Chordae tendineae and papillary muscles

129
Q

Semilunar valves open when

A

Ventricular pressure greater than aortic/ pulmonic pressure

130
Q

Semilunar valves close when

A

Aortic/ pulmonic pressure greater than ventricular pressure

131
Q

What are the three components of the aortic pressure curve

A

During systole, incisura, and during diastole

132
Q

During systole, the aortic pressure rises with

A

Ventricular contraction, 120 mmHg

133
Q

Aka of incisura

A

Dicrotic notch

134
Q

What occurs during incisura

A

Pressure fluctuation due to closing of the aortic valve

135
Q

During diastole, aortic pressure falls due to

A

Elastic recoil of the aorta to 80 mmHg

136
Q

Heart sounds can be recorded using a

A

Phonocardiogram

137
Q

How many heart sounds are there

A

4, S1-S4

138
Q

What is S1 heart sound

A

First heart sound, closure of AV valves, “lib”, beginning of systole

139
Q

What is S2 heart sound

A

Closure of the semilunar valve, “dub”, transition into diastole

140
Q

what is the S3 heart sound

A

Due to filling of ventricles in mid diastole

141
Q

Can you hear S4

A

No, only recorded using phonocardiograms

142
Q

What occurs during S4 heart sound

A

Due to atrial systole

143
Q

Where is the atrial repolarization

A

Hidden behind QRS

144
Q

What are the three components of the EKG

A

P wave, QRS complex, T wave

145
Q

P wave initiated by

A

SA node

146
Q

P wave represents

A

Atrial depolarization

147
Q

P wave precedes

A

Atrial systole

148
Q

QRS complex represents

A

Ventricular depolarization

149
Q

QRS complex precedes

A

Ventricular systole

150
Q

T wave represents

A

Ventricular repolarization

151
Q

T wave precedes

A

Ventricular diastole

152
Q

Are there any measuring forces in EKG

A

No just electricity

153
Q

What is work output of the heart

A

The amount of energy that the heart converts to work during each heartbeat

154
Q

What are the two forms of work the heart does

A

External work and kinetic energy of blood flow

155
Q

What is the external work the heart does

A

Move blood from veins to arteries (most of the work done)

156
Q

What is the kinetic energy of blood flow

A

Accelerates blood into the great arteries (minor fraction of heart work)

157
Q

What are the four factors that influence the strength of the contraction

A

Preload, afterload, contractility, and heart rate

158
Q

What is preload

A

End diastolic pressure in the ventricle, or length muscle is stretched before contraction, “filling”

159
Q

What is afterload

A

Forces against which cardiac muscle must overcome (arterial pressure, resistance to flow)

160
Q

Contractility is what type of state

A

Ionotropic state

161
Q

Contractility is a modification of

A

Strength independent of loading changes

162
Q

Contractility occurs where

A

Cellular level

163
Q

Contractility includes effects of

A

autonomic nervous system and hormones

164
Q

What indirectly increases contractility

A

Heart rate

165
Q

Increase heart rate does what to Ca2+

A

Accumulate faster than it is removed

166
Q

What is intrinsic regulation of the heart

A

Frank starlings mechanism

167
Q

What is frank starlings mechanism

A

Greater the heart muscle is stretched during filing, greater the force of contraction and the greater the quantity of blood pumped into the aorta

168
Q

How is there a greater force of contraction on a cellular level in heart

A

Cardiac muscles sarcomeres are short and resist stretch, increase in length increases number of functional cross bridges between actin and myosin therefore creating greater force of contraction

169
Q

Right atrial stretch increase heart rate by

A

10 - 20%

170
Q

Frank starlings law of heart says venous return equals what

A

Cardiac output

171
Q

Extrinsic regulation of heart is innervation of the heart via

A

Autonomic nervous system

172
Q

Sympathetic does what to heart

A

Increases heart rate, increases force of contraction

173
Q

Parasympathetic does what to heart

A

Decreases heart rate, weakly decreases force of contraction

174
Q

What are the three other influences on heart function

A

Potassium ions, calcium ions and temperature

175
Q

How does potassium ion influence heart function

A

Hyperkalemia causes weak contractions, slows heart rate, abnormal rhythms and potentially death

176
Q

How does calcium ions influences heart function

A

Hypercalcemia causes spastic contractions

177
Q

How does temperature influence heart function

A

Fever causes and increase in heart rate

178
Q

Location of SA node

A

Superior posterolateral right atrium

179
Q

How is the SA node self excited and has inherent rhythmicity

A

Sodium leak, higher resting membrane potential, lower threshold

180
Q

The SA node connects to the

A

Atrial muscle and internodal fibers

181
Q

Internodal fibers receives action potential from

A

SA node

182
Q

Internodal fibers connects to what node

A

AV node

183
Q

Why does AV node delay action potential

A

Low number of gap junctions, give atria time to contract before ventricles contract

184
Q

AV node slows velocity or rate

A

Slows velocity

185
Q

AV node located where

A

Posterior right atrium

186
Q

The purkinje fibers lead from the

A

AV node, through the AV bundle through the left and right bundle branches then throughout the ventricular muscle

187
Q

Does the purkinje system have a very fast or slow conduction velocity

A

Fast

188
Q

List the conduction system parts in order of fastest to slowest inherent firing rate

A

SA node, AV node, purkinje system

189
Q

What are the two electrodes to record voltage

A

Negative (reference) and positive (recording)

190
Q

A signal is detected by the oscilloscope when there is an

A

Electrical difference between the two electrodes

191
Q

An action potential is

A

Electrical events in a cell

192
Q

Electrocardiogram has electrodes placed

A

Outside of cell and has mass effect in bundle of cells

193
Q

EKG notices what

A

Deflection from zero lines due to depolarizations and repolarizations

194
Q

Action potential recordings are Monophasic or biphasic

A

Monophasic

195
Q

What is Monophasic

A

Only show amplitude of voltage changes as recorded at a point in a cell

196
Q

EKG recordings are Monophasic or biphasic

A

Biphasic

197
Q

Biphasic is

A

Records both amplitude and direction of waves of voltage changes through heart muscle

198
Q

Biphasic is what type of quantity

A

Vector

199
Q

PR interval is how long

A

.16 sec

200
Q

P R interval goes from what to what

A

SA node to AV node

201
Q

QT interval shows

A

Electrical events in ventricle

202
Q

The isoelectric line aka

A

Zero line

203
Q

Electrodes detect what

A

Waves of depolarization and repolarization throughout the heart tissue

204
Q

What is an electrode

A

Physical wired from machine to skin

205
Q

What is a lead

A

Set of electrodes used to make a recording

206
Q

If you have 10 electrodes how many leads

A

12

207
Q

The 12 lead EKG has what three lead groups

A

3 standard bipolar limb leads, 3 augmented unipolar limb leads, 6 precordial chest leads

208
Q

Why can you have multiple negative electrodes but have one positive

A

Positive electrode gives direction it is heading toward

209
Q

What are the standard bipolar limb leads

A

Lead 1,2,3

210
Q

Lead one positive lead goes where

A

Left shoulder/ wrist

211
Q

Lead one negative lead goes where

A

Right shoulder/ wrist

212
Q

Lead two positive lead goes where

A

Left ankle

213
Q

Lead two negative lead goes where

A

Right shoulder/ wrist

214
Q

Lead three positive lead goes where

A

Left ankle

215
Q

Lead three negative lead goes where

A

Left shoulder/ wrist

216
Q

What is einthoven’s triangle

A

Group of leads that form a triangle

217
Q

What is the electrode that is placed on the right ankle

A

Ground electrode

218
Q

What is einthovens law

A

2 = 1 + 3, in regards to the amplitude of the R wave

219
Q

What are the leads in the augmented unipolar limb leads

A

AVR, aVL, aVF

220
Q

Positive lead of aVR

A

Right wrist

221
Q

Negative lead of aVR

A

Left wrist and left ankle

222
Q

Positive lead of aVL

A

Left wrist

223
Q

Negative lead for aVL

A

Right wrist and right ankle

224
Q

Positive lead for aVF

A

Left ankle

225
Q

Negative lead for aVF

A

Left wrist and right wrist

226
Q

AVR should show what type of deflection

A

Negative due to going from left to right

227
Q

What are the precordial leads

A

V1 - V6

228
Q

V1 goes where

A

4 ICS to the right of sternum

229
Q

V2 goes where

A

4 ICS to the left of sternum

230
Q

V3 goes where

A

Between V2 and V4

231
Q

V4 goes where

A

5 ICS, Left mid clavicular line

232
Q

V5 should go where

A

5 ICS, left anterior axillary line

233
Q

V6 should go where

A

5 ICS, left mid axillary line

234
Q

What is the negative electrode in the precordial chest leads

A

Machine is used as reference point

235
Q

What is the mean vector

A

Average of all vectors

236
Q

Since atrial repolarization is not seen on EKG, the wave is actually called

A

atrial T

237
Q

The Q wave represents

A

Septal activation

238
Q

The R peak (most significant) represents

A

Apical activation

239
Q

The R wave return represents

A

Left ventricular activation

240
Q

The S wave represents

A

Left left ventricular activation

241
Q

The pattern of ventricular repolarization begins from

A

Apex towards the base of the heart

242
Q

What explains why the T wave is positive (lead 2)

A

Due to the pattern starting at apex then goes to base

243
Q

What is the U wave

A

Wave on ECG that is sometimes seen

244
Q

What causes U wave

A

Delayed replarization of purkinje fibers, prolonged repolarization of mid-myocardial M cells, after potentials resulting from mechanical forces in ventricular wall, repolarization of the papillary muscle

245
Q

Purpose of hexaxial reference system

A

Used to determine the vector of depolarization through the heart

246
Q

What is normal axis

A

0 to 90 degrees

247
Q

What is left axis deviation

A

QRS axis of 0 to -90 degrees

248
Q

What is right axis deviation

A

QRS axis of 90 to 180 degrees

249
Q

What is extreme axis

A

-90 to -180 degrees

250
Q

What is the average QRS axis

A

59 degrees

251
Q

To plot the QRS axis based on limb lead what is required

A

Use of any two of the six limb leads

252
Q

How to plot QRS axis

A

Take two leads and plot direction and magnitude, draw right angles, where they intersect is the axis of ventricular depolarization

253
Q

QRS axis can be estimated by comparing what

A

The size of the QRS complexes of all six limb leads

254
Q

What can cause left axis deviation

A

Short stock build, obesity, LV hypertrophy and left bundle branch block

255
Q

What can cause LV hypertrophy

A

Hypertension, aortic valve stenosis, aortic valve regurgitation

256
Q

What causes right axis deviation

A

Tall, long waist, lean build, RV hypertrophy, right bundle branch block

257
Q

What causes RV hypertrophy

A

Pulmonary valve stenosis/ regurgitation, interventricular septal defect, tetralogy fallot

258
Q

What is an interventricular septal defect

A

Still has hole from embryonic development, blood enters from left to right ventricle

259
Q

What is tetralogy fallot

A

Interventricular septal defect, over riding aorta, pulmonary stenosis, right ventricular hypertrophy

260
Q

Normal QRS voltage of sum of 1, 2, 3 should equal

A

2-4 mV

261
Q

Individually leads 1, 2, or 3 should be was QRS voltage

A

.5 - 2 mV

262
Q

Increased voltage of QRS is caused by what

A

Hypertrophy

263
Q

Decreased voltage of QRS is caused by

A

Damaged heart muscle

264
Q

QRS usually last for how long

A

.04 to .11 sec

265
Q

If prolonged QRS time occurs, it is due to

A

Bundle branch block or hypertrophy

266
Q

Current of injury is shown where EKG

A

ST segment

267
Q

Current injury is what

A

Acute damaged heart muscle (MI) does not repolarize normally and therefore becomes a source of current

268
Q

What is tachycardia

A

Resting heart rate faster than 110 bpm

269
Q

Tachycardia caused by

A

Fever, certain toxins, SNS activity

270
Q

What is bradycardia

A

Resting heart rate slower than 60 bpm

271
Q

Reason for bradycardia

A

Athlete, vagal stimulation

272
Q

Is sinus arrhythmia a normal variant

A

Yes

273
Q

Sinus arrhythmia is due to

A

Respiratory center in medulla exciting nearby vasomotor center

274
Q

Sinus arrhythmia can occur when heart rate increases with

A

Deep inspiration

275
Q

Conduction blocks can be due to

A

Some part of heart sustained damage

276
Q

What are the conduction blocks

A

SA block and AV blocks

277
Q

How to determine SA block

A

P wave missing, slower HR

278
Q

What are the different types of AV blocks

A

1st, 2nd and 3rd degree

279
Q

1st degree AV blood shows what

A

P to R interval long, delayed QRS

280
Q

2nd degree AV block looks like

A

Dropped beat, ventricles don’t have electrical activity, skipped beats

281
Q

3rd degree AV blocks look like what

A

AV node creates own pace, SA node communications with AV node is not happening

282
Q

Incomplete intraventricular block has what

A

Electrical alternans

283
Q

What are electrical alternans

A

Alternating strength signals, not effective repolarization causing weak signal

284
Q

Premature contractions are what

A

Contraction of the heart before the time they are normally expected

285
Q

Aka of premature contractions

A

Extrasystole and ectopic beat

286
Q

Premature contractions can occur in what part of heart

A

Atrial and ventricular

287
Q

A fib or V fib triggered by

A

Electrical shock, ischemia, dilated hearts, high potassium or tachycardia

288
Q

What occurs during atrial flutter

A

A single large wave that goes around the atria