Key Fact
BP and disorders
Normal BP: 120/80 mmHg. Hypertension: > 140/90. Coronary artery disease (atherosclerosis), angina, heart failure. Hyperlipidaemia → atheromatous plaques.
-- NCERT Class 11 Biology, Chapter 15, p. 202Circulation BP Disorders
8 MCQs1 revision card9-step worked example
Source: NCERT Human PhysiologyOfficial key: NTA-verifiedLast updated: 27 Sep 2026
Circulation BP Disorders, explained for NEET
Blood pressure (BP) is the force exerted by blood against arterial walls. It has two components: systolic pressure (~120 mmHg, during ventricular contraction) and diastolic pressure (~80 mmHg, during ventricular relaxation). NCERT Class 11 Biology Chapter 15, page 202, establishes the normal resting BP as 120/80 mmHg.
The high-frequency confusion in NEET: aspirants mix up hypertension with hypotension, and confuse the disorders associated with each. Hypertension (sustained BP > 140/90 mmHg) is the "silent killer" — often asymptomatic until organ damage occurs. Hypotension (BP < 90/60 mmHg) causes dizziness, fainting, and shock in severe cases.
Key circulatory disorders linked to BP:
- Atherosclerosis — deposition of cholesterol plaques in arterial walls, narrowing lumen, raising peripheral resistance and BP. Not the same as arteriosclerosis (general hardening/thickening of arterial walls).
- Coronary Artery Disease (CAD) — atherosclerosis specifically in coronary arteries, reducing myocardial blood supply.
- Angina pectoris — chest pain from reduced coronary blood flow (not a heart attack; reversible ischaemia).
- Myocardial infarction (heart attack) — complete blockage of coronary artery; irreversible necrosis of cardiac muscle.
Cardiac output link: CO = HR × SV. At rest, normal CO ≈ 5 L/min (heart rate ~72/min × stroke volume ~70 mL). Hypertension increases afterload, making the heart work harder, potentially leading to cardiac hypertrophy.
Watch-out: NEET frequently tests the distinction between atherosclerosis and arteriosclerosis, and between angina and myocardial infarction. The terminology precision matters — a single misread loses 5 marks (4 + 1 negative).
Can you answer these Circulation BP Disorders MCQs?
Select an option to see the explanation. Wrong answers show why your choice was tempting — and name the exact trap it exploits.
MCQ 1Easy RecallPractice
Normal blood pressure in a healthy young adult is:
Show answer and why every option is right or wrong
Answer: A. Normal resting BP is 120/80 mmHg (systolic/diastolic), as stated in NCERT Class 11 Biology Chapter 15, page 202.
Why B is wrong: 140/90 mmHg is the threshold above which hypertension is diagnosed, not the normal value.
Why C is wrong: 80/120 reverses systolic and diastolic — systolic (higher value) is always written first.
Why D is wrong: Blood pressure is measured in mmHg (millimetres of mercury), not mm of water. The unit matters.
MCQ 2Easy RecallPractice
Atherosclerosis differs from arteriosclerosis in that atherosclerosis specifically involves:
Show answer and why every option is right or wrong
Answer: C. Atherosclerosis is the deposition of fatty plaques (cholesterol, fibrous tissue) within the arterial intima, narrowing the lumen. Arteriosclerosis is the broader term for any hardening/thickening of arterial walls. NCERT Class 11 Biology Chapter 15.
Why A is wrong: Calcium-mediated hardening describes arteriosclerosis (general arterial stiffening), not the specific lipid-plaque deposition of atherosclerosis.
Why B is wrong: Veins are not the target of either condition — both atherosclerosis and arteriosclerosis affect arteries.
Why D is wrong: Capillary basement membrane thickening relates to diabetic microangiopathy, not atherosclerosis.
MCQ 3Concept TrapPractice
A person's blood pressure is checked repeatedly and consistently reads 138/88 mmHg. According to the NCERT criterion for diagnosing hypertension, this reading is:
Show answer and why every option is right or wrong
Answer: B. NCERT defines normal BP as 120/80 mmHg, but explicitly states that hypertension is diagnosed only when repeated checks show a reading of 140/90 mmHg or higher. A reading of 138/88 mmHg exceeds the normal baseline of 120/80 but does not reach 140 systolic or 90 diastolic, so by NCERT's own diagnostic criterion it is NOT hypertension (NCERT Class 11 Biology, Chapter 15, pages 202–203).
Why A is wrong: A confuses the normal baseline (120/80) with the diagnostic threshold (140/90). Exceeding the normal value is expected in many healthy people and is not, by itself, what NCERT uses to diagnose hypertension.
Why C is wrong: C invents a diastolic-only rule; NCERT's criterion is a combined reading of 140/90 or higher, not an isolated diastolic cutoff of 80 mmHg.
Why D is wrong: D misreads the stem: the readings here ARE repeated and consistent (as the stem states), so the reason this is not hypertension is that the values fall short of 140/90, not that a single reading was used.
MCQ 4Direct ApplicationPractice
Cardiac output is calculated as:
Show answer and why every option is right or wrong
Answer: C. CO = HR × SV. For a resting adult: ~72 beats/min × ~70 mL = ~5040 mL/min ≈ 5 L/min. NCERT Class 11 Biology Chapter 15.
Why A is wrong: Division of HR by SV has no physiological meaning and yields nonsensical units (beats²/mL·min).
Why B is wrong: BP × HR is not a defined cardiovascular parameter. Cardiac output specifically relates stroke volume to heart rate.
Why D is wrong: SV ÷ HR would give mL·min/beat — dimensionally incorrect for a volume-per-time output.
MCQ 5Direct ApplicationPractice
If resting heart rate is 75 beats/min and stroke volume is 68 mL, what is the cardiac output?
Show answer and why every option is right or wrong
Answer: A. CO = HR × SV = 75 × 68 = 5100 mL/min = 5.1 L/min. Straightforward application of the cardiac output formula.
Why B is wrong: 4.8 L/min would require 75 × 64 = 4800 — incorrect stroke volume used (perhaps confusing 68 with 64).
Why C is wrong: 5.4 L/min = 5400 mL/min would need SV of 72 mL (5400/75). Misremembering the given SV value.
Why D is wrong: 6.0 L/min = 6000 mL/min would require SV of 80 mL (6000/75) — significantly higher than the given 68 mL.
MCQ 6Direct ApplicationPractice
Angina pectoris is caused by:
Show answer and why every option is right or wrong
Answer: B. Angina pectoris results from temporary ischaemia of cardiac muscle due to reduced (not blocked) coronary blood flow. It is reversible — no permanent damage occurs. NCERT Class 11 Biology Chapter 15.
Why A is wrong: Complete blockage with tissue necrosis describes myocardial infarction (heart attack), not angina. Angina is reversible ischaemia without cell death.
Why C is wrong: Aortic rupture is a surgical emergency (aortic aneurysm/dissection), an entirely different pathology from angina.
Why D is wrong: Pericardial inflammation is pericarditis — presents with different pain characteristics (sharp, positional) and is not caused by coronary insufficiency.
MCQ 7Easy RecallPractice
Coronary Artery Disease (CAD) is essentially atherosclerosis affecting:
Show answer and why every option is right or wrong
Answer: D. CAD is defined as atherosclerosis specifically in the coronary arteries, reducing blood supply to the myocardium. NCERT Class 11 Biology Chapter 15.
Why A is wrong: Atherosclerosis of pulmonary arteries is rare and would cause pulmonary hypertension, not CAD.
Why B is wrong: Atherosclerosis of renal arteries causes renovascular hypertension, not coronary artery disease.
Why C is wrong: Atherosclerosis of carotid arteries causes cerebrovascular disease and stroke risk, not CAD.
MCQ 8Concept TrapPractice
A person's cardiac output increases during exercise primarily because:
Show answer and why every option is right or wrong
Answer: D. During exercise, sympathetic stimulation increases both heart rate (up to 150–200 bpm) and stroke volume (via increased venous return and contractility). CO = HR × SV, so both factors elevate cardiac output from ~5 L/min to 20–25 L/min.
Why A is wrong: Heart rate clearly increases during exercise (easily palpable). Claiming only SV changes ignores the obvious tachycardia response.
Why B is wrong: Blood pressure actually increases during exercise (systolic rises significantly). Decreased BP would indicate shock, not a healthy exercise response.
Why C is wrong: While heart rate rises, stroke volume does NOT decrease during moderate exercise — it increases due to the Frank-Starling mechanism (greater venous return stretches ventricles, increasing contraction force).
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Circulation BP Disorders: quick recall before you leave
How do you solve a Circulation BP Disorders question? A worked example
- 1
Given
A patient at rest has heart rate = 80 beats/min and stroke volume = 65 mL. During mild exercise, heart rate increases to 110 beats/min and stroke volume increases to 85 mL.
- 2
Required
Calculate cardiac output at rest and during exercise. By what factor does CO increase?
- 3
Concept
Cardiac output (CO) is the volume of blood pumped by the heart per minute, calculated as the product of heart rate and stroke volume.
- 4
Formula
CO = HR × SV
- 5
Substitution
• Rest: CO_rest = 80 × 65• Exercise: CO_exercise = 110 × 85
- 6
Calculation
• CO_rest = 80 × 65 = 5200 mL/min = 5.2 L/min• CO_exercise = 110 × 85 = 9350 mL/min = 9.35 L/min
Note: All given values (80, 65, 110, 85) are problem-defined exact values and do not limit significant figures in this context. - 7
Final answer
CO at rest = 5.2 L/min; CO during exercise = 9.35 L/min. Factor of increase = 9350/5200 ≈ 1.8 times.
- 8
Common trap
Students sometimes calculate only the heart rate increase (110/80 = 1.375×) and forget that stroke volume also increases. The actual CO increase factor accounts for BOTH variables changing simultaneously.
- 9
Similar NEET-style question
"If a person's heart rate doubles from 70 to 140 bpm during exercise and stroke volume increases from 70 mL to 100 mL, what is the percentage increase in cardiac output?" (Answer: Rest CO = 4900, Exercise CO = 14000; increase = ~186%)
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What to remember before solving Circulation BP Disorders questions
More in Human Physiology: 33 exam traps and mistakes · 2 formulas · 1 question pattern from its other lessons.
Circulation BP Disorders questions from past NEET papers
No question in our NEET 2020–2025 set targets this topic directly.
Sources
NCERT refs: Class 11 Biology Chapter 15, p.202
Page numbers are the ones printed in the current NCERT textbook (2023 rationalised edition), unless marked pre-2023. The books are free at ncert.nic.in.
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