Stress Hormone Cortisol and Immune Suppression
When an individual experiences stress, the Hypothalamic-Pituitary-Adrenal (HPA) axis is activated. This leads to the release of hormones, most notably cortisol, from the adrenal glands.
Cortisol's Impact on Immune Cells
Elevated levels of cortisol, particularly during chronic stress, play a significant role in modulating the immune system. The key effects include:
- Cortisol acts as an immunosuppressant.
- It can trigger apoptosis (programmed cell death) in lymphocytes, including crucial T cells.
- A decrease in T cells weakens the body's cell-mediated immunity, making it more vulnerable to infections.
Evaluation of Other Options
The other options present less accurate explanations:
- Option 1 is incorrect because while stress can increase blood pressure, this is not the primary mechanism by which the immune system is weakened.
- Option 2 is inaccurate; increased glucose primarily provides energy and does not directly neutralize WBCs in the manner described.
- Option 3 is partially related, as ACTH stimulates cortisol release, but ACTH itself does not directly destroy T cells; cortisol does.
Important Questions from Immune System
Bacterial infections are generally divided into two broad classes: intracellular and extracellular bacterial infections. Given below are some of the properties which are applicable for bacterial infections.
A. Humoral immune response is the main protective response against extracellular bacteria.
B. Innate immunity is not effective against intracellular bacterial pathogens.
C. Bacterial endotoxins do not induce an innate immune response.
D. Intracellular bacterial infections generally induce a cell-mediated immune response resulting in secretion of cytokines which activate macrophages.
Which one of the following combination of statements is correct?
The immunoglobulin heavy-chain that is rearranged first and is displayed on the surface of early stages of B-cell development is associated with:
Dr. Ralph M. Steinman was awarded Nobel Prize for his discovery on:
Which one of the following systems forms a chemical mediator that is involved in the mechanism of pain during inflammation?
Suresh was bitten by a poisonous snake and was immediately treated with anti-venom human immunoglobulin and was saved. A year later he was bitten by the same type of snake second time. Predict his response to the venom from second bite from the following:
