Cardiac glycosides are obtained from following plant source.

Correct Answer: B

Rationale: Cardiac glycosides are a group of medications used to treat heart conditions by increasing the strength of the heart muscle contractions. Strophanthus gratus is the correct plant source of cardiac glycosides. It contains active compounds like ouabain and strophanthin, which are used in the production of cardiac glycoside medications like digoxin. Rauwolfia serpentina, on the other hand, is the source of reserpine, a medication used to treat high blood pressure and certain psychiatric disorders, but not cardiac glycosides. Ricinus communis is the castor oil plant, which is not a source of cardiac glycosides but is known for its oil. Atropa belladonna is a plant that contains toxic alkaloids like atropine and scopolamine, not cardiac glycosides. In an educational context, understanding the sources of medications is crucial for healthcare professionals to ensure safe and effective treatment. Knowing the correct plant sources of drugs helps in proper prescribing, dosage calculation, and potential interactions. This knowledge is essential for pharmacists, nurses, and other healthcare providers involved in patient care.

Correct Answer: C

Rationale: The correct answer is C) Thins the blood because it inactivates clotting factors. Heparin is an anticoagulant medication that works by binding to antithrombin III, which in turn inactivates thrombin and several other clotting factors, thus preventing the formation of blood clots. This mechanism of action makes heparin effective in preventing and treating conditions such as deep vein thrombosis, pulmonary embolism, and stroke. Option A) Thins the blood by acting as an antiplatelet drug is incorrect because heparin primarily targets clotting factors, not platelets. Option B) Thins the blood because it decreases the synthesis of clotting factors is incorrect because heparin does not affect the synthesis of clotting factors but rather inhibits their activity. Option D) It thins the blood by promoting the lysis of fibrin is incorrect because heparin does not directly promote the breakdown of fibrin, which is the final product of the blood coagulation cascade. Understanding the mechanism of action of drugs like heparin is crucial for healthcare professionals, especially those involved in critical care settings where managing coagulation status is essential. By knowing how heparin works, nurses can safely administer and monitor its effects to prevent complications related to thrombosis or bleeding.

Correct Answer: B

Rationale: In the scenario of a client with atrial fibrillation requiring conversion to normal sinus rhythm, the treatment of choice is cardioversion (Option B). Cardioversion involves the restoration of normal heart rhythm through electrical or pharmacological methods. In the context of atrial fibrillation, cardioversion is particularly effective in cases where the arrhythmia is recent or if the patient is hemodynamically unstable. Digoxin (Option A) is not the first-line treatment for converting atrial fibrillation to normal sinus rhythm. Digoxin is more commonly used for rate control in atrial fibrillation to slow the heart rate, rather than for rhythm conversion. Metoprolol (Option C) and Verapamil (Option D) are both medications used for rate control in atrial fibrillation, rather than for direct conversion to normal sinus rhythm. These medications help in controlling the heart rate but do not directly address the rhythm abnormality. Educationally, understanding the appropriate pharmacological agents for different cardiac arrhythmias is essential for healthcare providers involved in the management of cardiovascular conditions. Knowing when to use cardioversion versus rate control medications like digoxin, metoprolol, or verapamil is crucial in providing effective and evidence-based care to patients with atrial fibrillation. This knowledge helps in improving patient outcomes and preventing potential complications associated with cardiac arrhythmias.

Correct Answer: B

Rationale: In this scenario, the correct answer is B) Decrease in smooth muscle vascular tone. Nifedipine is a calcium channel blocker that works by inhibiting the influx of calcium ions into smooth muscle cells in blood vessels, resulting in vasodilation and decreased smooth muscle vascular tone. This leads to a reduction in peripheral vascular resistance and subsequently lowers blood pressure. Option A) Arterial vasoconstriction is incorrect because nifedipine actually causes vasodilation, not vasoconstriction. Option C) Increase in myocardial oxygen consumption is incorrect as nifedipine is not known to increase myocardial oxygen demand; in fact, it may reduce myocardial oxygen demand due to its vasodilatory effects. Option D) Pronounced improvement in afterload is incorrect because nifedipine primarily acts on the preload (ventricular volume) by reducing systemic vascular resistance, rather than directly impacting afterload. Educationally, understanding the mechanism of action of medications like nifedipine is crucial for healthcare professionals in managing patients with hypertension. Knowing how a drug affects the cardiovascular system allows for appropriate prescribing, monitoring of effects, and patient education regarding their treatment plan.

Correct Answer: B

Rationale: Alteplase is a thrombolytic agent used in the treatment of acute myocardial infarction to dissolve blood clots in the coronary arteries. The correct answer is B) Activates plasminogen. Alteplase works by converting plasminogen into plasmin, which is an enzyme responsible for breaking down fibrin clots present in the bloodstream. This process helps to restore blood flow to the heart muscle and reduce the size of the clot causing the blockage. Option A) Activates antithrombin III is incorrect because antithrombin III is involved in the regulation of blood clotting through inhibition of clotting factors, not clot dissolution. Option C) Activates thrombin is incorrect because thrombin is a clotting factor that promotes clot formation, not clot breakdown. Option D) Blocks production of thromboxane A₂ is incorrect because thromboxane A₂ is involved in platelet aggregation, not clot dissolution. In an educational context, understanding how thrombolytic agents like alteplase work is crucial for healthcare providers managing patients with acute cardiovascular events. It is essential to differentiate between various pharmacological agents to administer appropriate treatment promptly and effectively. This knowledge can lead to improved patient outcomes and reduced complications associated with cardiovascular emergencies.