The heart receives deoxygenated blood from venous circulation and pumps oxygenated blood to the tissues.
Correct Answer
True
The right side of the heart receives deoxygenated blood via the venae cavae and sends it to the lungs. The left side receives oxygenated blood from the lungs and pumps it to the body.
Question 2
Beta-adrenergic blockers increase heart rate and myocardial contractility.
Correct Answer
False
Beta-blockers decrease heart rate and contractility by blocking beta-1 adrenergic receptors on the heart. This reduces myocardial oxygen demand.
Question 3
ACE inhibitors block the conversion of angiotensin I to angiotensin II.
Correct Answer
True
By inhibiting angiotensin-converting enzyme, ACE inhibitors prevent the formation of angiotensin II, a potent vasoconstrictor, thereby reducing blood pressure.
Question 4
Angiotensin II receptor blockers (ARBs) work at the same site as ACE inhibitors.
Correct Answer
False
ARBs block angiotensin II at its receptor site rather than preventing its formation. This is why ARBs do not cause the bradykinin-related cough associated with ACE inhibitors.
Question 5
Calcium channel blockers reduce heart rate and blood pressure by blocking calcium influx into cardiac and smooth muscle cells.
Correct Answer
True
By blocking calcium channels, these drugs reduce the force of contraction and slow electrical conduction, lowering both heart rate and blood pressure.
Question 6
Digoxin increases the force of myocardial contraction (positive inotropic effect).
Correct Answer
True
Digoxin strengthens the heart's contraction by increasing intracellular calcium levels, making it useful in treating heart failure.
Question 7
Digoxin has a wide therapeutic index and rarely requires blood level monitoring.
Correct Answer
False
Digoxin has a narrow therapeutic index. Serum levels must be monitored carefully because toxicity can cause life-threatening dysrhythmias.
Question 8
Hypokalemia increases the risk of digoxin toxicity.
Correct Answer
True
Low potassium levels enhance the effects of digoxin at cardiac binding sites, increasing the risk of toxicity even when digoxin levels are within normal range.
Question 9
Nitroglycerin works by vasodilation, which reduces cardiac preload.
Correct Answer
True
Nitroglycerin dilates veins (and at higher doses, arteries), reducing the amount of blood returning to the heart (preload) and decreasing myocardial oxygen demand.
Question 10
Loop diuretics like furosemide act on the proximal convoluted tubule.
Correct Answer
False
Loop diuretics act on the ascending loop of Henle, blocking sodium, potassium, and chloride reabsorption. This produces more potent diuresis than thiazide diuretics.
Question 11
Potassium-sparing diuretics can cause hyperkalemia.
Correct Answer
True
Potassium-sparing diuretics like spironolactone reduce potassium excretion. Without monitoring, potassium levels can rise to dangerous levels.
Question 12
Amiodarone is classified as a class III antidysrhythmic that prolongs the action potential.
Correct Answer
True
Amiodarone prolongs the action potential and refractory period, making it effective for both ventricular and supraventricular dysrhythmias.
Question 13
Statins lower cholesterol by increasing its production in the liver.
Correct Answer
False
Statins inhibit HMG-CoA reductase, the rate-limiting enzyme in cholesterol synthesis, thereby decreasing hepatic cholesterol production.
Question 14
Warfarin exerts its anticoagulant effect immediately after the first dose.
Correct Answer
False
Warfarin inhibits vitamin K-dependent clotting factor synthesis, but existing clotting factors must be depleted first. Full therapeutic effect takes several days.
Question 15
Heparin activates antithrombin III to provide immediate anticoagulation.
Correct Answer
True
Unlike warfarin, heparin works immediately by enhancing the activity of antithrombin III, which inactivates thrombin and several other clotting factors.
Question 16
The INR is used to monitor heparin therapy.
Correct Answer
False
The INR (International Normalized Ratio) monitors warfarin therapy. Heparin is monitored using the activated partial thromboplastin time (aPTT).
Question 17
Adenosine is used to treat supraventricular tachycardia and has a half-life of less than 10 seconds.
Correct Answer
True
Adenosine briefly blocks conduction through the AV node. Its extremely short half-life means it clears the bloodstream almost immediately.
Question 18
Antiplatelet medications like aspirin and clopidogrel prevent clot formation by inhibiting platelet aggregation.
Correct Answer
True
Aspirin inhibits thromboxane A2 production, and clopidogrel blocks the P2Y12 ADP receptor, both preventing platelets from clumping together.
Question 19
Tissue plasminogen activator (tPA) prevents new clots from forming.
Correct Answer
False
tPA is a thrombolytic that dissolves existing clots by converting plasminogen to plasmin, which breaks down fibrin. It does not prevent new clot formation.
Question 20
Epinephrine is the first-line medication used during cardiac arrest.
Correct Answer
True
Epinephrine stimulates alpha and beta adrenergic receptors, improving coronary and cerebral perfusion pressure during resuscitation efforts.
Question 21
Dopamine at low doses primarily causes renal vasodilation to increase urine output.
Correct Answer
True
At low doses (1-3 mcg/kg/min), dopamine stimulates dopaminergic receptors in renal vasculature, increasing renal blood flow and promoting diuresis.
Question 22
Beta-blockers can be safely discontinued abruptly without tapering.
Correct Answer
False
Abrupt discontinuation can cause rebound hypertension, tachycardia, and angina due to upregulation of beta receptors during chronic therapy. Doses must be tapered.
Question 23
Nitrates like nitroglycerin should be stored in dark glass containers because they are light-sensitive.
Correct Answer
True
Nitroglycerin degrades when exposed to light, heat, and moisture. It must be stored in the original dark glass container to maintain potency.
Question 24
Clients taking ACE inhibitors should be monitored for hyperkalemia.
Correct Answer
True
ACE inhibitors reduce aldosterone secretion, which decreases potassium excretion by the kidneys, potentially leading to dangerously elevated potassium levels.
Question 25
The nurse should assess blood pressure and heart rate before administering antihypertensive medications.
Correct Answer
True
Assessment of vital signs before administration helps determine if the drug is safe to give and establishes a baseline for evaluating therapeutic effectiveness.