Quiz Questions Week 15

8/11/2019 Quiz Questions Week 15

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Quiz for Week 15 - Questions

Questio n 1. Sketch the anatomy of the coronary vessels.

Question 2. Which ECG leads are best placed to record changes when the lesion is onthe (a) diaphragmatic aspect of the heart, (b) antero-septal region? Which arteries areinvolved?

Question 3. Indicate the time relationships of the arterial pressure wave to the heartsounds, ECG, and left ventricular pressure.

Questio n 4. Identify the serum lipoproteins and their role in atherosclerosis.

Question 5. Identify, and briefly comment on the functions of, the cells involved inatheroma formation.

Question 6. An obese 45-year-old man who smokes 20 cigarrettes a day is referred to thelipid clinic. Investigations found the following blood plasma results:

BP 160/100 Fasting glucose 7.5mM (3.27.0mM) Triglycerides 3.5 mM (< 2mM) Total cholesterol 8.0 mM (


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Quiz for Week 15 Answer Guides

Questio n 1. Sketch the anatomy of the coronary vessels.

Answer should indicate the origin of the coronary arteries above the aortic valve cusps, and theterritory of the major vessels and branches. The venous drainage should be identified. Someanomalous drainage going into the left atrium instead of the right contributes to the normal right toleft shunt.

Question 2. Which ECG leads are best placed to record changes when the lesion is onthe (a) diaphragmatic aspect of the heart, (b) antero-septal region? Which arteries areinvolved?

(a) II, III and aVF;(b) precordial leads, esp V2 V5; arteries follow on from Question 1

Question 3. Indicate the time relationships of the arterial pressure wave to the heartsounds, ECG, and left ventricular pressure.

This is a good diagram to draw as it encapsulates most of the critical ideas about the cardiac cycle:it is in every physiology book though the wave shapes tend to be artistic rather than realistic.

Question 4. Identify the serum lipoproteins and briefly describe their role inatherosclerosis.

LDL has the highest cholesterol content and transports lipids to the periphery; CVS risksincrease with levels.

VLDL contains triglyceride; risks increase with levels. HDL is involved in cholesterol transport out of the tissues back to the liver; increased levels

reduce risk. Total cholesterol risk increases sharply above about 5.2 mmol/l. Oxidised cholesterol

increases with age and disturbs the feedback control loops so that total cholesterol risesprogressively from infancy onwards.

Question 5. Identify, and briefly comment on the functions of, the cells involved inatheroma formation.

Endothelial cells: platelet aggregation/thrombus formation, LDL uptake. Platelets: form thrombus. Smooth muscle cells: take up LDL forming foam cells. Macrophages: oxidize LDL and take up lipids. Neutrophils: phagocytosis, secrete proteases and inflammatory mediators causing ongoing

damage.


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Question 6. An obese 45-year-old man who smokes 20 cigarrettes a day is referred to thelipid clinic. Investigations found the following blood plasma results:

BP 160/100 Fasting glucose 7.5mM (3.27.0mM) Triglycerides 3.5 mM (< 2mM) Total cholesterol 8.0 mM (


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endothelial cells and acts as a vasodilator by activation of guanylate cyclase, producing cyclic GMP,which triggers a cascade of phosphorylation reactions leading to relaxation of vascular smoothmuscle.

Question 10. Name the 2 major classes of cholesterol-lowering drugs and describe themechanism of action of each.

i) Statins: Examples are simvastatin and lovastatin.These act by inhibiting HMG-CoA reductase, the rate-limiting enzyme in the hepaticsynthesis of cholesterol. In the face of decreased cholesterol levels, the liver up-regulates its LDL receptors, thereby pulling in LDL-cholesterol from the periphery for usein bile acid synthesis.

ii) Anion exchange resins: Examples are cholestyramine and colestipol.These act by binding irreversibly to bile salts, thus interfering with the enterohepaticcirculation of bile salts between the gut and the liver and removing them from the body.Since bile salts are required for the emulsification and absorption of dietary fats, there isa resultant increase in hepatic LDL receptors which again result in an increased rate ofremoval of cholesterol from the blood for conversion to bile salts.

Question 11. Identify steps in problem-solving when counselling in the post-infarctsituation.

Problem clarification;Goal setting;Examine possible solutions and their impact on the patient;Develop action plan agreed with the patient.

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Quiz Questions Week 15