Question

Old people have weak immune system. What could be the reason?

Answer 1

Immune system:

1. Immune system (strongest protective system) is the combination of organs and processes of the body, it resists infection and toxins. Organs included in the immune system are the thymus, bone marrow, and lymph nodes.
2. Thymus (primary lymphoid organ) helps in the production of immune system cells (lymphocytes).
3. Thymus secretes a hormone called thymosin that stimulates the growth of White Blood Cells (WBCs) that is involved in the production of immunity.
4. Thymus is degenerated in old individuals, resulting in decreased production of thymosin which eventually decreases immunity. Thus, old people have a weak immune system.