Ch 18: Cardiovascular System Flashcards

1
Q

What is the difference between the right and left sides of the heart?

A

Right: receives oxygen-poor blood from tissues
Left: receives oxygenated blood from lungs

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

Where does the right side of the heart pump to?

A

Pumps to lungs to get rid of CO2, pick up O2 via pulmonary circuit

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

Where does the left side of the heart pump to?

A

Pumps to body tissues via systematic circuit

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

What are the receiving chambers of the heart?

A
  1. Right atrium

2. Left atrium

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

What is the difference between right and left atrium?`

A

Right: receives blood returning from systematic circuit
Left: receives blood returning from pulmonary circuit

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

What are the pumping chambers of heart?

A

Right and left ventricles

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

What is the difference between the right and left ventricles?

A

Right: pumps blood through pulmonary circuit
Left: pumps blood through systemic circuit

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

Where is the heart located?

A

Mediastinum

2/3 of heart is left of the midsternal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Compare the base and apex of the heart

A

Base: leans toward right shoulder

Apex points toward left hip

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

What is the approximate size of the heart?

A

Size of fist

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the 2 pericardium of the heart?

A
  1. Superficial fibrous pericardium

2. Deep 2-layered serous pericardium

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

What is the purpose for superficial fibrous pericardium?

A

Protects, anchors to surrounding structures and prevents overfilling

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

What are the 2 layers of serous pericardium?

A
  1. Parietal

2. Visceral

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

What portion of the heart does the parental layer line?

A

Internal surfaces of fibrous pericardium

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

What portion of the heart does the visceral layer (epicardium) line?

A

External surface of the heart

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

What separates the 2 serous pericardium layers?

A

Pericardial cavity

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

What is the purpose of the pericardial cavity?

A

Decreases friction

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

What is pericarditis?

A

Inflammation of pericardium

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

What is cardiac tamponade?

A

Excess fluid sometimes compresses heart that limits pumping ability

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

What does pericarditis cause?

A

Roughens membrane surfaces increasing pericardial friction and rubbing

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

What are the 3 layers of the heart wall?

A
  1. Epicardium
  2. Myocardium
  3. Endocardium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the epicardium?

A

Visceral layer of serous pericardium

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

What is myocardium?

A

Spiral bundles of contractile cardiac muscle cells

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

What is the endocardium?

A

Lines heart chambers that covers valves, consists of endothelial lining of blood vessels

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

Describe the characteristics of the cardiac skeleton

A

Crisscrossing interlacing layer of connective tissue

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

What is the purpose of the cardiac skeleton?

A
  1. Anchors cardia muscle fibers
  2. Supports great vessels and valves
  3. Limits spread of action potentials to specific paths
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Where are the locations of four chambers?

A

2 superior atria

2 inferior ventricles

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

What separates the atria?

A

Interatrial septum

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

What separates the ventricles?

A

Interventricular septum

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

What is an auricle?

A

Appendages that increase atrial volume

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

Where are the auricles located?

A

Left and right atrium

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

What is the purpose for auricles?

A

Contribute to propulsion of blood

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

What are the 3 veins that empty into the right atrium?

A

Superior vena cava, inferior vena cave, coronary sinus

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

How many pulmonary veins go into the left atrium?

A

4

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

What is the purpose for the papillary muscles?

A

Anchors chordae tendinae to prevent inversion or prolapse of mitral and tricuspid valves on systole

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

Where does the right ventricle pump blood?

A

Pulmonary trunk

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

Where does the left ventricle pump blood?

A

Aorta

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

What is the purpose of atrioventricular valves?

A

Prevents back flow into atria when ventricles contract

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

What are 2 AV valves?

A
Tricuspid valve (right)
Mitral valve (left)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What are the purposes for chordae tendineae?

A
  1. Anchors cusps to papillary muscles
  2. Hold valve flaps in closed position
  3. Ensure undirectional blood flow through heart
  4. Open and close in response to pressure changes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What is the purpose for semilunar valves?

A

Prevents back flow into ventricles when ventricles relax by opening and close in response to pressure changes

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

What are the 2 SL valves?

A
  1. Aortic semilunar valve

2. Pulmonary semilunar valve

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

What is incompetent valve?

A

When blood backflows so heart re-pumps blood over and over

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

What occurs during vavular stenosis?

A

Stiffs flaps that constrict opening to where the hear must exert more force to pump blood

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

Why would the left ventricle of the heart have a thicker cell wall than the right?

A

Pumping with great pressure do to greater after load

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

How are valves replaced?

A

Mechanical, animal, cadaver valves

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

Describe the route of the pulmonary circuit

A

Right atrium → tricuspid valve → right ventricle → pulmonary semilunar valve → pulmonary trunk → pulmonary arteries → lungs → pulmonary veins → left atrium

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

Describe the route of the systemic circuit

A

Left atrium → mitral valve → left ventricle → aortic semilunar valve → aorta → systemic circulation

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

What is the difference between pulmonary and systemic circuit?

A

P: short-low pressure circulation
S: long, high-friction circulation

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

Compare the anatomy of the 2 ventricles

A

Left ventricle wall is 3x thicker than right

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

Compare the volumes of blood that are pumped to the pulmonary and systematic circuit

A

Equal volumes fo blood is pumped

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

When would blood supply be pumped to the heart?

A
  1. Delivered when heart is relaxed

2. Left ventricle receives most blood supply

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

What is the purpose of the anastomoses?

A
  1. Provide additional routes for blood delivery

2. Cannot compensate for coronary artery occulusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

Identify the difference between left and right coronary artery

A

Left: supply left atrium and left ventricle
Right: supply right and most of right ventricle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

What are the cardiac veins?

A

Collect blood from capillary beds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

What is the coronary sinus?

A

Empties into right atrium formed by merging cardiac viens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

What cardiac veins the coronary sinus empties into?

A
  1. Great cardiac vein
  2. Middle cardiac vein
  3. Small cardiac vein
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

What is angina pectoris?

A

Thoracic pain caused by fleeting deficiency in blood delivery to myocardium causing cells to weaken

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

What is myocardial infarction?

A

Caused by prolonged coronary blockage where areas of cell death repaired with non contractile scar tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

What are the junctions between cardiac cells?

A

Intercalated discs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

What is purpose of desmosomes in the cardiac muscle?

A

Prevent cells from separating during contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

What is the purpose of gap junctions in the cardiac muscle?

A

Allows ions to pass from cell to cell electrically couple adjacent cell allowing the heart to function as a single unit?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

What is the term for behaving as a single coordinated unit?

A

Functional syncytium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

Describe the structure of cardiomyocytes

A

Striated, short, branched, fat interconnected containing a central nuclei

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

What are the components of the cardiac muscle?

A
  1. Cardiomyocytes
  2. T tubules
  3. Simple SR
  4. Large mitochondria
66
Q

How are cardiac muscles similar to the skeletal muscle?

A
  1. Depolarization opens few voltage-gated fast Na+ channels in sarcolemma causing a reversal in membrane potential
  2. Depolarization wave down T tubule allowing SR to release Ca2+
  3. Excitation-contraction coupling occurs when Ca2+ binds to troponin and filaments slide
67
Q

How are cardiac muscles different from skeletal?

A
  1. Autorhythmicity
  2. All cardiomyocytes contract aș a unit
  3. Long absolute refractory period preventing tetanic contractions
  4. Depolarization wave also opens slowing Ca2+ channels in sarcolemma causing SR to release its Ca2+
  5. Ca2+ surge prolongs the depolarization phase (plateau)
  6. Action potential and contractile phase last much longer allowing blood ejection from heart
  7. Repolarization result of inactivation of Ca2+ channels and opening of voltage-gated K+ channels where Ca2+ is pumped back into SR and extracellularly
68
Q

Describe the action potential of the cardiac muscle cells

A
  1. Depolarization is due to Na+ influx through fast voltage-gated Na+ channels. A positive feedback cycle rapidly opens many Na+ channels, reversing the membrane potential. Channel inactivation ends this phase.
  2. Plateau phase is due to Ca2+ influx through slow Ca2+ channels. This keeps the cell depolarized because few K+ channels are open.
  3. Repolarization is due to Ca2+ channels inactivating and K+ channels opening. This allows K+ efflux, which brings the membrane potential back to its resting voltage.
69
Q

Why does the cardiac muscle have so many mitochondria?

A
  1. Greater dependence on aerobic respiration

2. Little anaerobic respiration ability

70
Q

What can be used by the heart that is derived from the skeletal muscles?

A

Lactic acid

71
Q

What is the pathway when ischemic cells are present?

A

Ischemic cells → anaerobic respiration → lactic acid → high [H+] → high [Ca2+] → mitochondrial damage → decrease ATP production → Gap junctions close → fatal arrhythmias

72
Q

What NS can alter heart rhythm?

A

ANS

73
Q

Does the heart need nervous stimulus stimulation to depolarize and contract?

A

No

74
Q

What factors cause coordinated heartbeat?

A
  1. Presence of gap junctions

2. Intrinsic cardiac conduction system

75
Q

Describe the intrinsic cardiac conduction system

A
  1. Network of non contractile (autorhythmic) cells

2. Initiate and distribute impulses → coordinated depolarization and contraction of heart

76
Q

Describe the mechanism for pacemaking

A
  1. Pacemaker potential: Repolarization closes K+ channels and opens slow Na+ channels causing ion imbalance. Unstable resting membrane potential is due to opening of slow Na+ channels and closing of K+ (continual depolarization)
  2. Depolarization: action potential releases threshold opening Ca2+ channels causing an influx raising the action potential
  3. Repolarization occurs by the inactivation of Ca+ channels and K+ efflux brings membrane potential back to negative
77
Q

What are sequences of excitation?

A
Sinoatrial node →
Atrioventricular node →
Atrioventricular bundle →
Right and left bundle branches →
Subendocardial conducting network (Purkinje fibers)
78
Q

What is function of Sinoatrial node?

A
  1. Pacemaker of heart in right atrial wall
  2. Depolarizes faster than rest of myocardium
  3. Generates impulses about 75x/minute (sinus rhythm)
79
Q

What is the function of the Atrioventricular node?

A
  1. Delays impulses approximately 0.1 seconds
  2. Smaller fibers that have fewer gap junction
  3. Allows atrial contraction prior to ventricular contraction
80
Q

What is the inherent rate of the AV node?

A

50x/minutes in absence of SA node input

81
Q

What is the inherent rate SA node?

A

100X/minute tempered by extrinsic factors

82
Q

What is the AV bundle (bundle of His)?

A

Only electrical connection between atria and ventricle because they are not connected by gap junctions

83
Q

What is the purpose of the right and left bundle branches?

A

Carry impulses toward apex of heart

84
Q

What is the subendocardial conducting network (Purkinje fibers)?

A
  1. Complete pathway through interventricular septum into apex and ventricular walls
  2. More elaborate on left side of heart
85
Q

What are the inherent rate of the (Purkinje fibers)

A

AV bundle and subendocardial conducting network depolarize 30X/minute in absence of AV node input

86
Q

Describe the intrinsic cardiac conduction system

A
  1. SA nodes generates impulse
  2. Impulse pause at the AV node
  3. AV bundle connects the the atria to the ventricles
  4. The bundle branches conduct the impulses through the inter ventricular septum
  5. The subendocardial conducting network depolarizes the contractile cells of both ventricles
87
Q

What occurs during an arrhythmia?

A

Irregular heart rhythms caused by uncoordinated atrial and ventricular contractions

88
Q

What occurs during a fibrillation?

A

Rapid, irregular contractions useless for pumping blood, circulation ceases and brain death

89
Q

What treats fibrillation?

A

Defibrillation

90
Q

What is abnormal pacemaker

A

Ectopic focus caused by defective SA node

91
Q

What is an extrasystole?

A

Ectopic focuse sets high rate causing premature contraction

92
Q

What is a heart block?

A

Few (partial) or no (total) impulses reach ventricles caused by a defective AV node

93
Q

How is a heart block treated?

A

Artificial pacemaker

94
Q

How is heartbeat modified?

A

ANS via cardiac centers in the medulla oblongata

95
Q

How does the sympathetic NS modify heartbeat?

A

increase rate and force

96
Q

How does the parasympathetic NS modify heartbeat?

A

decrease rate

97
Q

How does the Cardioacceleratory center modify heartbeat?

A

Sympathetic – affects SA, AV nodes, heart muscle, coronary arteries

98
Q

How does the Cardioinhibitory center modify heartbeat?

A

Parasympathetic – inhibits SA and AV nodes via vagus nerves

99
Q

What is a Electrocardiogram?

A

Composite of all action potentials generated by nodal and contractile cells at given time

100
Q

What are the 3 waves of an ECG?

A
  1. P wave
  2. QRS complex
  3. T wave
101
Q

What occurs in the P wave?

A

Depolarization of SA node in atria: atrial depolarization

102
Q

What occurs in the QRS complex?

A

Ventricular depolarization and atrial repolarization

103
Q

What occurs during the T wave?

A

Ventricular repolarization

104
Q

What is the P-R interval?

A

Beginning of atrial excitation to beginning of ventricular excitation

105
Q

What is the S-T segment?

A

Entire ventricular myocardium depolarized

106
Q

What is the Q-T interval?

A

Beginning of ventricular depolarization through ventricular repolarization

107
Q

Describe the mechanism of an electrocardiograph

A
  1. Atrial depolarization caused by the SA node (P wave)
  2. Completion of atrial depolarization where impulse is delayed at the AV node
  3. Ventricular depolarization at apex. Atrial depolarization (QRS complex)
  4. Ventricular depolarization is complete
  5. Ventricular depolarization begins at apex (T wave)
  6. Ventricular repolarization is complete
108
Q

What causes the sound of heart (lub-dub)?

A
  1. First as AV valves close; beginning of systole
  2. Second as SL valves close; beginning of ventricular diastole
  3. Pause indicates heart relaxation
109
Q

What are heart murmurs?

A

Abnormal heart sounds; usually indicate incompetent or stenotic valves

110
Q

What is the cardiac cycle?

A

Blood flow through heart during one complete heartbeat: atrial systole and diastole followed by ventricular systole and diastole

Series of pressure and blood volume changes

111
Q

What is the difference between systole and diastole?

A

S: contraction
D: relaxation

112
Q

What occurs during ventricular filling?

A
  1. AV valves are open; pressures
  2. 80% of blood passively flows into ventricles
  3. Atrial systole occurs, delivering remaining 20%
113
Q

What is the end diastolic volume?

A

Volume of blood in each ventricle at end of ventricular diastole

114
Q

What occurs during ventricular systole?

A
  1. Atria relax; ventricles begin to contract
  2. Rising ventricular pressure → closing of AV valves
  3. Isovolumetric contraction phase (all valves are closed)
115
Q

What occurs in the ejection phase of ventricular systole?

A

Ventricular pressure exceeds pressure in large arteries, forcing SL valves open

116
Q

What is end systolic volume?

A

Volume of blood remaining in each ventricle after systole

117
Q

What occurs during isovolumetric relaxation?

A
  1. Ventricles relax; atria relaxed and filling
  2. Backflow of blood in aorta and pulmonary trunk closes SL valves
  3. When atrial pressure exceeds that in ventricles → AV valves open; cycle begins again at step 1
118
Q

What is a dicrotic notch?

A

Brief rise in aortic pressure as blood rebounds off closed valve

119
Q

What is the cardiac output?

A

Volume of blood pumped by each ventricle in one minute

120
Q

What is the equation of CO?

A

CO = heart rate(bpm) (HR) × stroke volume (volume of blood pumped out by one ventricle with each beat (SV)

121
Q

What is the normal CO?

A

5.25L/min

122
Q

What is cardiac reserve?

A

Difference between resting and maximal CO

123
Q

What is the maximal CO of trained athletes?

A

35L/min

124
Q

What is equation to calculate stroke volume?

A

SV = EDV – ESV
EDV affected by length of ventricular diastole and venous pressure
ESV affected by arterial BP and force of ventricular contraction

125
Q

What are the factors that affect SV?

A

Preload
Contractility
Afterload

126
Q

What is preload?

A

Degree of stretch of cardiac muscle cells before they contract (Frank-Starling law of heart)

127
Q

What is the important factor stretching cardiac muscle?

A

Venous return

128
Q

What is venous return?

A

The amount of blood returning to heart

129
Q

What is the purpose for venous return?

A
  1. Slow heartbeat and exercise increase venous return

2. Increased venous return distends (stretches) ventricles and increases contraction force

130
Q

What is a length-tension relationship?

A

At rest, cardiac muscle cells shorter than optimal length

131
Q

What is contractility?

A

Contractile strength at given muscle length, independent of muscle stretch and EDV

132
Q

How is contractility increased?

A
  1. Sympathetic stimulation → increased Ca2+ influx → more cross bridges
  2. Positive inotropic agents
133
Q

What are examples of positive inotropic agents?

A

Thyroxine, glucagon, epinephrine, digitalis, high extracellular Ca2+

134
Q

How is contractility decreased?

A

Negative inotropic agents such as Acidosis, increased extracellular K+, calcium channel blockers

135
Q

What is factor increases heart rate?

A

Positive chronotropic factors

136
Q

What factor decreases heart rate?

A

Negative chronotropic factors

137
Q

What is afterload?

A

Pressure ventricles must overcome to eject blood

138
Q

What can increase afterload?

A

Hypertension resulting in increased ESV and reduced SV

139
Q

How is the Sympathetic NS activated?

A

Emotional or physical stressors

140
Q

What hormone cases increased contractility to fire pacemakers more rapidly?

A

Norepineriphine

141
Q

How does norepinephrine increase contractility?

A

Binds to β1-adrenergic receptors increasing HR

Increasing contractility; faster relaxation

142
Q

What hormone slows down heart rate?

A

Acetylcholine hyperpolarizes pacemaker cells by opening K+ channels → slower HR

143
Q

What is vagal tone?

A

Parasympathetic dominant influence

144
Q

What occurs during an Atrial (Bainbridge) reflex?

A
  1. Stretch of atrial walls stimulates SAnode → increasing HR
  2. Also stimulates atrial stretch receptors, activating sympathetic reflexes
145
Q

How is the Atrial (Bainbridge) reflex?

A

Sympathetic reflex initiated by increased venous return, hence increased atrial filling

146
Q

What are the hormones that increases heart rate and contractility?

A
  1. Epinephrine

2. Throxine

147
Q

What maintains normal heart function?

A

Intra- and extracellular ion concentrations

148
Q

What is hypocalcemia?

A

Depression of the heart

149
Q

What is hypercalcemia?

A

Increase in HR and contractility

150
Q

What is hyperkalemia?

A

Alters electrical activity → heart block and cardiac arrest

151
Q

What is hypokalemia?

A

Feeble heartbeat; arrhythmias

152
Q

Wha is tachycardia?

A

Abnormally fast heart rate (>100beats/min)

153
Q

What is bradycardia?

A

Heart rate slower than 60beats/min

154
Q

What are the factors that increase HR?

A
  1. Age
  2. Gender
  3. Exercise
  4. Body temperature
155
Q

What is congestive heart failure?

A
  1. Progressive condition; CO is so low that blood circulation inadequate to meet tissue needs
  2. Reflects weakened myocardium
156
Q

What causes weakened myocardium?

A
  1. Coronary atherosclerosis—clogged arteries
  2. Persistent high blood pressure
  3. Multiple myocardial infarcts
  4. Dilated cardiomyopathy (DCM)
157
Q

What is pulmonary congestion?

A

Left side fails → blood backs up in lungs

158
Q

What is peripheral congestion?

A

Right side fails → blood pools in body organs → edema

159
Q

What is the treatment for heart congestion?

A

Removing fluid, reducing afterload, increasing contractility

160
Q

What are the 2 types of congenital heart defects?

A
  1. Mixing of oxygen-poor and oxygen-rich blood, e.g., septal defects, patent ductus arteriosus
  2. Narrowed valves or vessels → increased workload on heart, e.g., coarctation of aorta
161
Q

What is tetralogy of fallot?

A

Both types of disorders present: Mixing of oxygen-poor and oxygen-rich blood and narrowed valves or vessels