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
- Which components of psychoneuro immunological system is not effected by glucocorticoids
- Brief stress enhances the activity of immune system as evidenced by the action of
- Choose the correct sequence of response of immune system
A. Synthesizes antibodies which comprises immunoglobulins
B. Immune system identifies foreign substances in the body
C. Immunoglobulins specifically designed to bind the antigens
D. Destroy the antigens
Choose the correct answer from the options given below: There are number of specific T cell surface molecules involved in various functions of adaptive immune response. Column X represents a list of T cell surface molecules and Column Y with the possible functional characteristics:
Column X
Column Y
A.
T cell receptor
(i)
binds to CD40 on B cells and APCs and triggers activation of APCs and activation/differentiation of B cells.
B.
CD28
(ii)
binds to MHC class I molecules and restricts I cytotoxic cells to recognizing only peptide presented on MHC class I
C.
CD8
(iii)
binds to B7 - 1, 2 or CD80/86 on B cells and APCs, which triggers T cell activation.
D.
CD154
(iv)
consists of two poly-peptide chains α and β and some consist of poly-peptide chains γ and δ.
Which of the following option has all correct matches?
Which one of the following influenza A virus subtypes caused severe avian flu and was responsible for disease outbreak in the year 1997 in Hong Kong?
