What kind of changes happen to vessels when the pH of blood reduces?

Choice A Reason:

Boxed warnings, also known as black box warnings, are the strictest warnings put in the labeling of prescription drugs by the FDA when there is reasonable evidence of an association of a serious hazard with the drug. However, they do not necessarily indicate that a drug should only be given in life-threatening circumstances. Instead, they highlight the potential for serious or life-threatening risks and advise on how to use the drug safely.

Choice B Reason:

While some boxed warnings may include information about teratogenic effects (effects that can cause birth defects), this is not their primary purpose. Boxed warnings are broader and can apply to various serious risks, not just teratogenicity. Therefore, this choice is too narrow to be correct.

Choice C Reason:

This is the correct answer. Boxed warnings are designed to alert prescribers to serious or life-threatening risks associated with a drug and provide guidance on how to mitigate these risks. This can include recommendations for monitoring, dosage adjustments, or avoiding certain populations. The goal is to ensure that prescribers are fully aware of the risks and can take appropriate measures to minimize harm to patients.

Choice D Reason:

Boxed warnings do not typically provide information about antidotes for toxicity. While managing toxicity is an important aspect of drug safety, boxed warnings focus on alerting prescribers to serious risks and how to mitigate them, rather than detailing specific antidotes.

Choice A Reason:

Hyperplasia refers to an increase in the number of cells in an organ or tissue, usually resulting in an increase in the size of the organ or tissue. This process is often a response to a stimulus and can be physiological or pathological. However, hyperplasia does not involve the replacement of one cell type with another, as seen in this case.

Choice B Reason:

Dysplasia is characterized by abnormal growth and development of cells within tissues or organs. It often indicates a precancerous condition and involves changes in cell size, shape, and organization. While dysplasia can occur in the respiratory tract, it does not describe the replacement of one type of epithelial cell with another.

Choice C Reason:

This is the correct answer. Metaplasia is the process by which one type of adult cell is replaced by another type of adult cell that is not typical for that tissue. In this case, the normal columnar ciliated cells in the bronchial airway have been replaced by stratified squamous epithelial cells, a common adaptation in response to chronic irritation from smoking.

Choice D Reason:

Hypertrophy refers to an increase in the size of cells, leading to an increase in the size of the affected organ or tissue. This process does not involve a change in cell type, making it an incorrect choice for this scenario.