📝 Step 5 — KMU Past Papers & Exam Learning

This section contains KMU-style past paper questions designed to strengthen conceptual understanding. Focus on understanding explanations rather than memorizing answers.

🎯 How to Study KMU Past Papers

• Read the question carefully.
• Think about the answer before looking.
• Read the explanation slowly.
• Understand the reasoning behind the correct answer.
• Revise difficult questions again.

MCQ 1

Question:
A patient with high serum LDL has progressive narrowing of coronary arteries. Which biochemical event best explains the earliest arterial wall change?

Options:
Cholesterol conversion into bile salts
Oxidative modification of LDL
Hydrolysis of triglycerides in plasma
Synthesis of phospholipids in liver
Transport of cholesterol by HDL

Correct Answer:
Oxidative modification of LDL

Explanation:
Oxidized LDL is taken up by macrophages, leading to foam cell formation and early atherosclerotic change.

MCQ 2

Question:
A lipid molecule stabilizes cell membranes and also serves as a precursor for steroid hormones. Which structural feature is most responsible for its membrane-stabilizing property?

Options:
Branched amino acid chain
Four fused hydrocarbon rings
Long peptide backbone
Repeated glucose residues
Free phosphate group

Correct Answer:
Four fused hydrocarbon rings

Explanation:
Cholesterol has a rigid steroid nucleus that fits between phospholipids and regulates membrane fluidity.

MCQ 3

Question:
A man develops chest pain during exertion that improves with rest. Which pathophysiological event best explains this presentation?

Options:
Sudden rupture of venous thrombus
Reduced coronary flow during demand
Excessive bile acid synthesis
Failure of reverse cholesterol transport alone
Acute bacterial inflammation of myocardium

Correct Answer:
Reduced coronary flow during demand

Explanation:
Stable angina occurs when narrowed coronary arteries cannot meet increased myocardial oxygen demand.

MCQ 4

Question:
A patient with myocardial infarction presents 12 hours after chest pain. Which marker is most useful because of high cardiac specificity?

Options:
Myoglobin
Lactate dehydrogenase
Creatine kinase total
Cardiac troponin T
Aspartate aminotransferase

Correct Answer:
Cardiac troponin T

Explanation:
Cardiac troponins are highly specific for myocardial injury and remain elevated for several days.

MCQ 5

Question:
A patient has elevated triglyceride-rich particles synthesized by the liver. Which lipoprotein is mainly increased?

Options:
High-density lipoprotein
Low-density lipoprotein
Very low-density lipoprotein
Chylomicron remnant
Lipoprotein(a)

Correct Answer:
Very low-density lipoprotein

Explanation:
VLDL transports endogenous triglycerides synthesized in the liver.

MCQ 6

Question:
Atherosclerotic plaque becomes clinically dangerous when its fibrous cap ruptures. What is the immediate consequence?

Options:
Bile salt retention
Platelet-rich thrombus formation
HDL receptor activation
Calcium entry into hepatocytes
Reduced intestinal lipid absorption

Correct Answer:
Platelet-rich thrombus formation

Explanation:
Plaque rupture exposes thrombogenic material, causing platelet activation and coronary thrombosis.

MCQ 7

Question:
A patient with recurrent myocardial infarction has CK-MB measured serially. Why is CK-MB useful in this setting?

Options:
It remains raised for several weeks
It is absent from cardiac muscle
It returns to baseline relatively early
It rises only after seven days
It directly measures LDL oxidation

Correct Answer:
It returns to baseline relatively early

Explanation:
CK-MB normalizes earlier than troponin, so a second rise may suggest reinfarction.

MCQ 8

Question:
Which lipid class is most directly involved in forming the basic bilayer of cell membranes?

Options:
Triglycerides
Phospholipids
Steroid hormones
Chylomicrons
Bile pigments

Correct Answer:
Phospholipids

Explanation:
Phospholipids are amphipathic molecules that form the structural basis of biological membranes.

MCQ 9

Question:
A malnourished patient develops tachycardia, edema, and high-output cardiac failure. Which biochemical defect is most likely responsible?

Options:
Defective collagen hydroxylation
Impaired thiamine-dependent ATP production
Reduced vitamin D activation
Excess ketone body utilization
Increased purine degradation

Correct Answer:
Impaired thiamine-dependent ATP production

Explanation:
Thiamine deficiency impairs energy metabolism and may produce wet beriberi with cardiac failure.

MCQ 10

Question:
Which preventive strategy best represents secondary prevention of cardiovascular disease?

Options:
Promoting healthy diet in schoolchildren
Screening high-risk adults for dyslipidemia
Cardiac rehabilitation after infarction
Reducing salt intake in the whole population
Preventing smoking initiation in adolescents

Correct Answer:
Screening high-risk adults for dyslipidemia

Explanation:
Secondary prevention detects and treats early disease or risk states before complications occur.

MCQ 11

Question:
A drug reduces hepatic cholesterol synthesis and increases LDL receptor expression. Which group does it belong to?

Options:
Nitrates
Statins
Fibrates
Thrombolytics
Anticoagulants

Correct Answer:
Statins

Explanation:
Statins inhibit HMG-CoA reductase and lower LDL by increasing hepatic LDL uptake.

MCQ 12

Question:
A patient develops arrhythmia due to altered resting membrane potential of cardiac cells. Which ion is most closely involved?

Options:
Potassium
Calcium
Sodium
Magnesium
Chloride

Correct Answer:
Potassium

Explanation:
Potassium is the major ion responsible for maintaining resting membrane potential in cardiac muscle.

MCQ 13

Question:
Which laboratory finding most directly supports increased risk of atherosclerotic coronary disease?

Options:
Raised serum albumin
Raised LDL cholesterol
Reduced serum urea
Raised alkaline phosphatase
Reduced fasting lactate

Correct Answer:
Raised LDL cholesterol

Explanation:
High LDL promotes cholesterol deposition in arterial walls and increases atherosclerotic risk.

MCQ 14

Question:
A patient has reduced removal of cholesterol from peripheral tissues. Which lipoprotein function is impaired?

Options:
Chylomicron triglyceride delivery
LDL cholesterol delivery
HDL reverse transport
VLDL triglyceride export
IDL hepatic conversion

Correct Answer:
HDL reverse transport

Explanation:
HDL removes excess cholesterol from tissues and returns it to the liver.

MCQ 15

Question:
During myocardial ischemia, cardiac cell membrane integrity is lost. Which diagnostic principle explains biomarker elevation?

Options:
Increased renal excretion of enzymes
Leakage of intracellular proteins into blood
Reduced hepatic synthesis of albumin
Increased intestinal lipid absorption
Activation of bile acid secretion

Correct Answer:
Leakage of intracellular proteins into blood

Explanation:
Myocardial injury releases intracellular proteins such as troponins and CK-MB into circulation.

MCQ 16

Question:
Which lesion represents progression beyond fatty streak due to smooth muscle migration and extracellular matrix deposition?

Options:
Fibrous plaque
Normal intima
Fresh embolus
Venous thrombus
Cardiac vegetation

Correct Answer:
Fibrous plaque

Explanation:
Fibrous plaque forms when smooth muscle cells migrate and produce collagen and matrix in the intima.

MCQ 17

Question:
A patient with acute coronary syndrome receives aspirin. Which therapeutic action is most relevant?

Options:
Lowering hepatic cholesterol synthesis
Reducing platelet aggregation
Relaxing bronchial smooth muscle
Increasing bile acid excretion
Enhancing calcium absorption

Correct Answer:
Reducing platelet aggregation

Explanation:
Antiplatelet drugs reduce thrombus formation after plaque rupture.

MCQ 18

Question:
Which biochemical fate of cholesterol is important for its elimination from the body?

Options:
Conversion into bile acids
Conversion into glycogen
Oxidation into pyruvate
Conversion into amino acids
Storage as hemoglobin

Correct Answer:
Conversion into bile acids

Explanation:
Cholesterol is mainly eliminated after hepatic conversion into bile acids and excretion in bile.

MCQ 19

Question:
A sudden unexpected death occurs in a middle-aged man with severe coronary artery narrowing. Which aspect is most important for medicolegal interpretation?

Options:
Routine vitamin level estimation
Circumstances and autopsy findings
Diet history alone
Blood group determination only
Family income assessment

Correct Answer:
Circumstances and autopsy findings

Explanation:
Sudden cardiovascular death requires correlation of circumstances, history, and postmortem findings.

MCQ 20

Question:
A drug relieves anginal pain mainly by reducing preload and myocardial oxygen demand. Which drug group is most appropriate?

Options:
Fibrates
Nitrates
Thiazides
Cephalosporins
Antacids

Correct Answer:
Nitrates

Explanation:
Nitrates reduce venous return and myocardial workload, improving oxygen supply-demand balance.

📌 Important Exam Strategy

KMU examinations often test integrated understanding rather than isolated facts. Focus on linking anatomy, embryology, histology, and clinical concepts when reviewing questions.

✅ Revision Tip

If you can explain the reason behind the correct answer without looking at notes, your concept is strong.