Question

Which of the following stimuli are considered to be potentially injurious to cells?

1) Infection
2) Genetic mutations
3) Immunologic reactions
4) All of the above

Answer 1

Potentially injurious stimuli to cells include infection, genetic mutations, and immunologic reactions such as hypersensitivities. Type I hypersensitivities involve mast cells, while Type II involves cell lysis and antibody reactions, and Types I-III are B-cell mediated, contrasting with T-cell mediated Type IV hypersensitivity.

Step-by-step explanation:

Potentially Injurious Stimuli to Cells

Cells can be injured by a variety of stimuli that disrupt their normal function. The following stimuli are considered potentially injurious to cells:

1. Infection - Pathogens such as bacteria, viruses, and fungi can cause cell damage through direct invasion or through the toxins they produce.
2. Genetic mutations - Alterations in the DNA can lead to malfunctioning proteins and enzymes, which can harm the cell's integrity and function.
3. Immunologic reactions - These include hypersensitivities that can cause cell injury. For example, type I hypersensitivities involve inflammatory molecules released by mast cells, leading to allergic reactions. Type II hypersensitivities involve cell lysis (cytotoxicity) and strong antibody reactions against antigens.

All of these factors can disrupt cellular homeostasis and may result in cell death if not controlled. It's also important to recognize the role of the immune system in some of these processes, such as hypersensitivity reactions. Types I-III hypersensitivities are B-cell mediated, while type IV hypersensitivity is a T-cell mediated phenomenon, illustrating the complex interactions between cells in the immune system.