Which of the Following Accurately Describes the Mechanism of Action

question 13

Multiple Choice

Which of the following accurately describes the mechanism of action of digoxin?

• A) Digoxin stimulates Na/K ATPase. Stimulation of Na/K ATPase increases intracellular concentration of Na+ ions. Increased intracellular Na+ decreases the activity of the Na/Ca exchanger and allows intracellular Ca++ concentrations to increase. Increased intracellular Ca++ increases the formation of actinomyosin and increases the force of myocardial contractions.
• B) Digoxin binds to and inhibits Na/K ATPase. Inhibition of Na/K ATPase decreases intracellular concentration of Na+ ions. Decreased intracellular Na+ increases the activity of the Na/Ca exchanger and allows intracellular Ca++ concentrations to decrease. Decreased intracellular Ca++ increases the formation of actinomyosin and increases the force of myocardial contractions.
• C) Digoxin binds to and inhibits Na/K ATPase. Inhibition of Na/K ATPase increases intracellular concentration of Na+ ions. Increased intracellular Na+ decreases the activity of the Na/Ca exchanger and allows intracellular Ca++ concentrations to increase. Increased intracellular Ca++ increases the formation of actinomyosin and increases the force of myocardial contractions.
• D) None of the above are correct.

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Definitions:

Payback Period

The duration of time it takes for an investment to generate cash flows sufficient to recover its initial cost.

Discount Rate

The discount rate that's critical in the process of valuing future cash flows today, within the framework of discounted cash flow analysis.

Net Present Value

A financial metric used to evaluate the profitability of an investment, calculated by subtracting the present value of cash outflows from the present value of cash inflows.

Capital Budgeting

The process of planning and evaluating expenditures on assets whose cash flows are expected to extend beyond one year, like new machinery, equipment, or projects.