Module 5: Cardiac Physiology Flashcards

1
Q

List the 5 functions of the circulatory system

A
  1. Gas exchange
  2. Nutrient and Water delivery and absorption
  3. Removal of head and metabolic waste
  4. Immunity and defence
  5. Cell communication
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

T/F
The circulatory system is a closed loop system

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How is blood both serial and parallel?

A

System as a whole is serial
Systemic circulation is parallel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe series flow (in terms of electrons)

A

Electrons can only flow down one path in a clockwise direction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Describe parallel flow (in terms of electrons)

A

Electrons can flow down many paths in a counter clockwise direction, but can flow down intermediate pathways

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

The septum of the heart does what?

A

Separates the left and ride sides of the heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

The heart consists of how many pumps?

A

2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Each pump is divided into how many chambers? what are they called?

A
  1. An upper chamber: the atrium. And a lower chamber: the ventricle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

T/F
Veins only carries deoxygenated blood

A

False!
It carries blood TOWARDs the heart
See the pulmonary vein for example

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe the flow of blood throughout the body

A
  • O2 rich blood is pumped from the left ventricle to the aorta
  • O2 rich blood is delivered to the tissues and organs
  • nutrients are removed from the blood while waste is added into the blood
  • oxygen poor blood circulated into the veins and into the right atria via the vena cavae
  • Blood is pumped into the right ventricle then through the pulmonary artery to the lungs
  • CO2 is removed form blood and O2 is added back
  • O2 rich blood flows through pulmonary vein into left atria where it is pumped into the left ventricle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

When there is greater pressure behind a cardiac valve, what happens?

A

It opens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

When there is greater pressure in front of a cardiac valve, what happens?

A

It closes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Where is the atrioventricular valve located?

A

Between the atria and ventricles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

To prevent inversion of the valves, what are they connected to?

A

The papillary muscles of the ventricular walls via the chordae tendinae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

The right AV valve is also called what?

A

The tricuspid valve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

The left AV valve is also known as what?

A

The bicuspid valve and mitral valve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Where are the semilunar valves located?

A

Between the ventricles and arteries that leave them

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Where is the pulmonary valve lcoated?

A

Between the right ventricle and the pulmonary artery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Where is the aortic valve located?

A

Between the left ventricle and the aorta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

T/F
Semilunar valves contain chordae tendinae to prevent inversion

A

False
Inversion is prevented solely on their shape

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Valvular heart disease (VHD) is the dysfunction of what?

A

The valves in the heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

VHD arises in which two forms

A

Either regurgitation or stenosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What characterizes regurgitation

A

Occurs when a valve does not close properly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Describe regurgitation

A

Valves do not close properly leading blood flowing back into the compartment in which is came from. Can occur in any of the 4 valves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Regurgitation can lead to what?

A

Irregular heart rhythms and unnecessary stress on the walls
Can lead to heart failure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What characterizes stenosis

A

The narrowing of the valve due to thickening/inflammation of the valve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Describe stenosis

A

Can occur in any of the heart valves
Inhibits flow of the blood out of the ventricle/atria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Intercalated discs are composed of what?

A

Desmosomes and gap junctions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What are the function of desmosomes in intercalated discs?

A

To mechanically hold the cells together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What are the function of gap junctions in intercalated discs?

A

To allow cells to communicate and spread action potentials from cell-cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is the function of intercalated discs?

A

To allow the chambers of the heart to coordinate a contraction and efficiently push out blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Describe the structure of the pericardial sac

A

A double membrane consisting of the fibrous and serous layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is the function of the pericardial sac?

A

To protect the heart from the rest of the chest cavity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What is the function of the fibrous layer?

A

To anchor the heart to the surrounding walls, keeping it in place during movement
To prevent it from overfilling with blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is the structure of the serous layer?

A

Divided into the parietal and visceral pericardium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What is the function of the serous layer?

A

To lubricate the heart with pericardiac fluid and prevent friction during activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

T/F
The heart is a mechanical organ

A

False!
It’s an electro-mechanical organ

u goon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What are cardiac auto-rhythmic cells?

A

Specialized cardiac muscle cells that can generate action potentials

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Where are cardiac auto-rhythmic cells located?

A

In the:
sinoatrial (SA) node
atrioventricular (AV) node
Bundle of His
Purkinje fibres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Describe the location of the SA node

A

Located in the right atrial wall near the opening of the superior vena cava

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Describe the location of the AV node

A

Located in the right atria where the right atria and right ventricle come together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Describe the location(s) of the Bundle of His

A

Cells arise from the AV node and divide into two bundle branches that travel down each side of the septum to the bottom of the heart where they curve around and travel back towards the atria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Where do purkinje fibres originate from and go to

A

Branch off of the Bundle of His and spread along the inner surface of the ventricles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What are the pacemaker cells?

A

The auto-rhythmic cells in the SA node

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What would happen if there were no pace maker cells?

A

The heart wouldn’t beat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What do pacemaker cells do?

A

They control heart rate, keeping it at about 70-80 bpm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

T/F
Atrial contraction accounts for 80% of total ventricular filling

A

False!
It passive filling accounts for that.
The other 20% is from atrial contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What requirements need to be met for a successful cardiac excitation?

A

Atrial excitation and contraction should be complete before the onset of ventricular contraction
Excitation of the cardiac muscle fibres need to be coordinated
The pair of atria and the pair of ventricles must be functionally coordinated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

If the ventricles were to contract at the same time as the atria, what would occur?

A

Incomplete ventricular filling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Uncoordinated depolarization of the cells in the ventricles is also called what?

A

Ventricular fibrillation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

What is the function of interatrial and internodal pathways?

A

They move the wave of excitation faster than possible by gap junctions alone

52
Q

Describe the interatrial pathway: it’s location and function

A

Extends from the right atrium to the left atrium
Ensures that the wave of excitment spreads across both atria at the same time

53
Q

Describe the function of the internodal pathway

A

Connects the SA node to the AV node

54
Q

What is the purpose of the AV node delay?

A

To ensure that the atria have fully contracted before the ventricles contract. This ensures maximal atrial emptying

55
Q

T/F
The ventricles rely more on the bundle of His and purkinje fibres than the atria to transmit their electrical signal

A

True

56
Q

What is the resting membrane potential for a cardiac myocyte?

A

80mV

57
Q

When a cardiac myocyte becomes excited, what channels open?
What does the membrane depolarize towards?

A

Voltage-gated Na+ channels
50mV

58
Q

The opening of the sodium ion channel triggers a potassium channel creating a balance of membrane potential. What is this called?

A

Plateau potential

59
Q

T/F
L-type Ca2+ channels in the T tubules open during the plateau phase

A

True

60
Q

What is the refractory period?

A

The period during which a cardiac myocyte cannot be re-stimulated. Occurs during the plateau phase

61
Q

Who invented the ECG?

A

Williem Einthoven

62
Q

In the first ECG, where were the electrical leads and ground electrode placed?

A

Electrical leads on the right and left arm, and left leg
Ground electrode on the right leg

63
Q

Lead I recorded electrical activity where?

A

From the right to left arm

64
Q

Lead II recorded electrical activity where?

A

From the right arm to left leg

65
Q

Lead III recorded electrical activity where?

A

From the left arm to the left leg

66
Q

How many leads are in the modern day ECG. How many are physical?

A

12 total
9 are physical

67
Q

How are the remaining leads determined?

A

Mathematically from leads I II and II

68
Q

What does an ECG measure?

A

The changes of electrical potentials that originate in the heart but are transmitted through the body

69
Q

ECGs allow us to identify what medical thing?

A

Cardiac abnormalities

70
Q

The standard ECG graph is from what lead?

A

Lead II

71
Q

Observed upward detections in the graph are caused from what?

A

Depolarization

72
Q

Observed downward reflections in the graph are from what?

A

Repolarizations

73
Q

What characterizes the P wave?

A

The atria’s depolarization

74
Q

What characterizes the QRS complex?

A

The wave of excitation traveling down the bundle of His and purkinje fibres to depolarize the ventricles

75
Q

What characterizes the T wave?

A

Where the ventricles repolarize

76
Q

The PR segment represents what?

A

The AV node delay

77
Q

The ST segment represents what?

A

The time during which the ventricles are contracting and emptying

78
Q

The TP segment indicates what?

A

The time during which the ventricles are relaxing and filling

79
Q

The QT segment indicates what?

A

The electrical depolarization and repolarization of the ventricles

80
Q

What is tachycardia?

A

Heart rate exceeding 100bpm

81
Q

What can tachycardia be due to?

A

Exercise, caffeine, or an electrical abnormality within the heart

82
Q

What is the affect of tachycardia on CO and ventricular filling

A

Can cause decreased CO and decreased ventricular filling

83
Q

The kind of tachycardia (either wide or narrow) is identified by what part of the ECG graph?

A

The QRS complex

84
Q

What is extrasystole?

A

A heartbeat initiated by the purkinje fibres rather than the SA node

85
Q

What is happening with the ventricles and atria in someone experiencing extrasystole?

A

Their ventricles are contracting before the atria

86
Q

What is Ventricular fibrillation (V-fib)

A

When the heart is quivering rather than pumping due to abnormal electrical activity within the ventricles

87
Q

What does the ECG look like in patients experiencing V-fib?

A

Irregular QRS complex with no clear P waves

88
Q

What occurs in complete heart block?

A

The impulse generated by the SA node does not travel to the ventricles

89
Q

What does the ECG look like in someone experiencing Complete heart block

A
  • Continuous P wave occurs
  • QRS complex occurs that doesn’t follow a P wave
90
Q

What is systole?

A

Contraction

91
Q

What is diastole?

A

Relaxation

92
Q

HELLO

A

this card is a reminder to look at the mechanical activity of the heart. Looks like a good short answer question. U should know its details.

93
Q

Describe isometric contraction

A

Contraction in the left ventricle that creates enough pressure to close the AV valve, but not yet strong enough to open the aortic valve

94
Q

When using a stethoscope, what is the first heart sound from? What does it sound like? What does it signal the beginning of?

A

Occurs when the AV valve closes
Sounds like “lub”
Signals the beginning of ventricular systole

95
Q

When using a stethoscope, what is the second heart sound from? What does it sound like? What does it signal the beginning of?

A

Occurs when the semilunar valves close
Sounds like “dub”
Signals the onset of ventricular diastole

96
Q

What is a heart murmur?

A

When a valve is not functioning properly and the typical lub-dub sounds are altered

97
Q

Describe an aortic stenosis murmur

A

Occurs in the stenotic valve
Valve does not open fully
Causes whistling-like sound

98
Q

Describe a mitral valve regurgitation murmur

A

Valve does not close properly
Called a leaky valve
Allows backwards flow of blood
Creates a swishing/gurgling type sound

99
Q

What is cardiac output?

A

The volume of blood pumped out by each ventricle over a minute

100
Q

How do you calculate cardiac output?

A

Heart rate * Stroke volume

101
Q

What is stroke volume?

A

The amount of blood ejected by ventricle contraction

102
Q

How does the parasympathetic system innervate the heart

A

Innervates via the vagus nerve
Mainly innervates onto the atria (specifically SA and AV nodes)

103
Q

How does the sympathetic system innervate the heart

A

Mainly innervates the ventricles (but will also innervate the atria)

104
Q

List how the parasympathetic system regulates the heart

A

Slows heart rate
Reduced the AV nodes excitability
Shortens atrial action potentials

105
Q

How does the parasympathetic system reduce heart rate

A

Releases acetylcholine at the SA node
Increases K+ permeability, which hyperpolarizes the cell

106
Q

How does the parasympathetic system reduce AV node excitability?

A

Increases K+ permeability, hyperpolarizing it

107
Q

How does the parasympathetic system shorten atrial action potentials?

A

Increases K+ permeability, creating a shorter plateau phase, where the Ca2+ usually enters to create a strong contraction

108
Q

List how the sympathetic system regulates the heart

A

Increases heart rate
Increases AV node excitability
Enhances conduction speeds
Increases contractibility of cardiac muscles

109
Q

How does the sympathetic system increase heart rate?

A

Releases norepinephrine at the SA node

110
Q

Hoe does the sympathetic system increase AV node excitability?

A

Decreases the AV node delay

111
Q

How does the sympathetic system increase contractibility of cardiac muscles

A

Increased Ca2+ permeability during the plateau phase allows for more calcium ions to pass into the cell, increasing contractility

112
Q

What are some of the ways heart rate can be activated to increase or decrease?

A

Injury to the vagus nerve
Activity
Fever

113
Q

Give an example of extrinsic control of stroke volume

A

The sympathetic nervous system

114
Q

Give an example of intrinsic control of stroke volume

A

The volume of blood in the ventricle at the end of diastole

115
Q

What is the Frank-Starling Law?

A

That increasing end-diastolic volume increases SV
The greater the diastolic filling, the greater the systolic emptying

116
Q

What is preload also known as?

A

Venous return

117
Q

What is preload?

A

The amount of blood returning to the ventricle

118
Q

What is afterload?

A

The force that the ventricle is pushing against
(if there is increased pressure in the aorta then the left ventricle is contracting against this extra load

119
Q

What is ejection fraction?

A

The amount of blood that is pumped out of the ventricles relative to the amount of blood that was in the ventricles before contraction

120
Q

What is the calculation for ejection fraction?

A

Stroke volume / end diastolic volume

121
Q

The left coronary artery branches off into what?

A

The left anterior descending artery and the circumflex artery

122
Q

What is the purpose of coronary circulation?

A

To supply oxygen rich blood to the cardiac muscle

123
Q

T/F
The amount of blood that can flow through the coronary arteries decreases during systole

A

True

124
Q

What is the primary fuel source of the heart? Why?

A

Free fatty acids
Because they are slow burning and easily stored

124
Q

What is the primary fuel source of the heart? Why?

A

Free fatty acids
Because they are slow burning and easily stored