After suffering a heart attack, a middle-aged man is counseled to attend physical therapy. This is an example of:

Choice A Reason:

To determine how much of the medication remains in the body after a certain period, we need to understand the concept of half-life. The half-life of a medication is the time it takes for the concentration of the drug in the bloodstream to reduce by half. For Medication A, the half-life is 3 hours. After 12 hours, which is four half-lives, the amount of medication remaining can be calculated step by step.

Choice B Reason:

Let’s break down the calculation. Initially, the patient receives 400 mg of Medication A. After the first half-life (3 hours), the amount of medication remaining is 400 mg ÷ 2 = 200 mg. After the second half-life (6 hours), the amount remaining is 200 mg ÷ 2 = 100 mg. After the third half-life (9 hours), the amount remaining is 100 mg ÷ 2 = 50 mg. Finally, after the fourth half-life (12 hours), the amount remaining is 50 mg ÷ 2 = 25 mg. Therefore, 375 mg is not a correct answer.

Choice C Reason:

Similarly, 150 mg is not correct. As shown in the detailed calculation, the amount of medication decreases by half every 3 hours. After 12 hours, the remaining amount is 25 mg, not 150 mg. This choice does not align with the half-life calculation.

Choice D Reason:

This is the correct answer. The step-by-step calculation shows that after 12 hours, which is equivalent to four half-lives, the amount of Medication A remaining in the patient’s body is 25 mg. This demonstrates the principle of half-life and how the concentration of a drug decreases over time.

Choice A Reason:

Chronic stress can significantly impact mental health, leading to conditions such as depression. The persistent activation of the stress response system, particularly the release of cortisol, can alter brain function and structure, contributing to mood disorders. Studies have shown that prolonged exposure to stress hormones can lead to changes in the brain that are associated with depression.

Choice B Reason:

Impaired cognitive function is another consequence of chronic stress. Elevated levels of cortisol over an extended period can damage the hippocampus, a region of the brain involved in memory and learning. This can result in difficulties with concentration, memory, and decision-making. Chronic stress has been linked to cognitive decline and an increased risk of neurodegenerative diseases.

Choice C Reason:

Chronic stress can also affect the immune system, leading to autoimmune diseases. The continuous activation of the stress response can cause immune dysregulation, where the body’s immune system mistakenly attacks its own tissues. This can result in conditions such as rheumatoid arthritis, lupus, and other autoimmune disorders.

Choice D Reason:

Overactive immune function is not typically associated with chronic stress. Instead, chronic stress often leads to a weakened immune response, making the body more susceptible to infections and illnesses. Therefore, this choice is incorrect.

Choice E Reason:

Cardiovascular disease is a well-documented consequence of chronic stress. The persistent release of stress hormones like adrenaline and cortisol can lead to increased blood pressure, heart rate, and the formation of artery-clogging deposits. These changes can increase the risk of heart disease, heart attacks, and strokes.