40 Year 3: Endocrine and Metabolic Pathology exam questions on LIPID AND LIPOPROTEIN DISORDERS MCQs for medical students. Includes MCQs, answers, explanations a
This MCQ set contains 40 questions on LIPID AND LIPOPROTEIN DISORDERS MCQs in the Year 3: Endocrine and Metabolic Pathology unit. Each question includes the correct answer and a detailed explanation for active recall and exam preparation.
Correct answer: C – Chylomicrons
Chylomicrons are the largest lipoproteins and transport dietary triglycerides from the intestines to other tissues. They are primarily involved in the transport of dietary fats.
Correct answer: B – Transport cholesterol from cells back to the liver for excretion
HDL (High-Density Lipoprotein) transports cholesterol from cells and tissues back to the liver for excretion, earning it the name "good cholesterol." High HDL levels are associated with lower cardiovascular risk.
Correct answer: B – Hormone-sensitive lipase
Hormone-sensitive lipase breaks down triglycerides into glycerol and free fatty acids, primarily in adipose tissue during lipolysis in response to hormonal signals.
Correct answer: B – It transforms into LDL
VLDL (Very-Low-Density Lipoprotein) carries triglycerides from the liver to tissues. As VLDL loses triglycerides through lipoprotein lipase action, it transforms into LDL.
Correct answer: C – Insulin
Insulin promotes lipogenesis (fat synthesis) and inhibits lipolysis (fat breakdown), while glucagon and epinephrine have opposite effects, stimulating lipolysis.
Correct answer: B – Mutation in LDL receptor genes
Familial hypercholesterolemia results from mutations affecting LDL receptors, leading to elevated LDL cholesterol. Heterozygous form has one mutated allele; homozygous has both alleles mutated.
Correct answer: B – Tendon xanthomas
Tendon xanthomas are yellowish nodules on tendons, commonly around the Achilles tendon or hands, characteristic of severe hypercholesterolemia, particularly familial hypercholesterolemia.
Correct answer: B – Acute pancreatitis
Severe hypertriglyceridemia can lead to acute pancreatitis, presenting with abdominal pain, nausea, and vomiting. This is a serious complication of markedly elevated triglyceride levels.
Correct answer: B – Milky appearance of retina due to extremely elevated triglycerides
Lipemia retinalis is a rare condition where triglycerides are extremely elevated (usually 2000-4000 mg/dL), leading to a milky appearance of the retinal vessels during eye examination.
Correct answer: B – Atorvastatin
Atorvastatin is a statin (HMG-CoA reductase inhibitor) that is the primary treatment for lowering LDL cholesterol. Other statins include simvastatin and rosuvastatin.
Correct answer: B – Beta-oxidation
Beta-oxidation is the process where free fatty acids are transported to mitochondria and converted into acetyl-CoA, which enters the Krebs cycle for energy production.
Correct answer: C – Apolipoprotein E
Familial dysbetalipoproteinemia results from genetic defects in apolipoprotein E, leading to elevated IDL (Intermediate-Density Lipoprotein) cholesterol and premature atherosclerosis.
Correct answer: B – Associated with familial dysbetalipoproteinemia
Palmar xanthomas (yellowish deposits on the palms) along with tuberous xanthomas on elbows and knees are characteristic of familial dysbetalipoproteinemia.
Correct answer: B – Fibrates
Fibrates (such as fenofibrate and gemfibrozil) are primarily used to lower triglycerides and can sometimes raise HDL cholesterol levels.
Correct answer: B – Elevated chylomicrons due to lipoprotein lipase deficiency
Type I hyperlipoproteinemia is characterized by elevated chylomicrons due to lipoprotein lipase deficiency, leading to severe hypertriglyceridemia.
Correct answer: B – Before age 50 years
In heterozygous familial hypercholesterolemia, early-onset cardiovascular disease with heart attacks or strokes often occurs at a younger age, typically before 50 years.
Correct answer: B – Reduces cholesterol absorption in the intestine
Ezetimibe is a cholesterol absorption inhibitor that lowers LDL cholesterol by reducing cholesterol absorption in the intestine.
Correct answer: B – Diabetes mellitus (diabetic dyslipidemia)
Diabetic dyslipidemia is characterized by elevated triglycerides and low HDL cholesterol due to insulin resistance and diabetes mellitus.
Correct answer: B – Lipid profile
A lipid profile (or lipid panel) is the standard test that measures total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides to assess lipid status.
Correct answer: B – In childhood or adolescence
Homozygous familial hypercholesterolemia presents with extremely high LDL cholesterol and severe atherosclerosis, with heart attacks occurring in childhood or adolescence.
Correct answer: B – Yellowish patches on eyelids or around the eyes
Xanthelasma refers to yellowish patches on the eyelids or around the eyes, which are cholesterol deposits commonly seen in hypercholesterolemia.
Correct answer: C – Bile acid sequestrants
Bile acid sequestrants (like cholestyramine and colesevelam) lower LDL cholesterol by binding bile acids in the intestine, forcing the liver to use cholesterol to make more bile acids.
Correct answer: C – 150 minutes
Regular physical activity of at least 150 minutes of moderate-intensity exercise per week (such as brisk walking or cycling) is recommended for improving lipid profiles.
Correct answer: C – IDL (Intermediate-Density Lipoprotein)
IDL (Intermediate-Density Lipoprotein) is a transitional form between VLDL and LDL, involved in lipid metabolism as VLDL loses triglycerides.
Correct answer: C – Acetyl-CoA carboxylase
Acetyl-CoA carboxylase is a key enzyme in lipogenesis, catalyzing the first committed step in fatty acid synthesis by converting acetyl-CoA to malonyl-CoA.