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PY5.1-16 | Cardiovascular Physiology — Practice Quiz
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Cardiac muscle has a long refractory period that prevents tetanus. This long refractory period is primarily due to which phase of the cardiac action potential?
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The first heart sound (S1) is produced by closure of the AV valves. At what point in the cardiac cycle does S1 occur?
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A patient's oxygen consumption is 300 mL/min. Arterial blood O2 content is 200 mL/L and mixed venous blood O2 content is 140 mL/L. Using Fick's principle, what is the cardiac output?
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According to the Frank-Starling mechanism, what happens when venous return increases?
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Mean arterial pressure (MAP) is calculated as DBP + 1/3 (pulse pressure). For a patient with BP 150/90 mmHg, the MAP is:
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The baroreceptor reflex is the most important short-term mechanism for blood pressure regulation. The baroreceptors in the carotid sinus transmit afferent signals via which cranial nerve?
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In the JVP waveform, the 'a' wave is produced by:
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A 70-year-old diabetic patient on antihypertensive medication feels dizzy and nearly faints every time she stands up from a chair. Her lying BP is 140/85 and standing BP (after 3 minutes) is 105/60. The most likely diagnosis is:
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The AV node introduces a delay of approximately 0.1 seconds in the transmission of the cardiac impulse. What is the physiological importance of this delay?
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An ECG shows absence of P waves, an irregularly irregular ventricular rhythm, and a normal QRS duration. The most likely diagnosis is:
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On a standard ECG, the QRS complex represents:
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A patient with nephrotic syndrome (heavy proteinuria) develops generalised oedema. Which Starling force is primarily altered to cause this oedema?
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A road traffic accident victim loses approximately 1 litre of blood. On examination, he is conscious, anxious, tachycardic (HR 110), with cold clammy extremities and a BP of 100/80. This presentation is most consistent with:
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A 55-year-old patient with known ischaemic heart disease presents with severe breathlessness that worsens on lying flat (orthopnoea) and bilateral lung crackles. Chest X-ray shows pulmonary congestion. JVP is normal. Which type of heart failure explains this presentation?
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Coronary blood flow is unique because it occurs predominantly during which phase of the cardiac cycle?
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