Question

Why do old people have weak immune system?

Answer 1

1. The thymus gland is the primary lymphoid organ.
2. It is located on the dorsal side of the heart and aorta.
3. It is a lobular structure.
4. It secretes the peptide hormone Thymosin which plays a major role in T-cell differentiation, which provides cell-mediated immunity.
5. It also provides humoral immunity by stimulating antibody production.
6. In older individuals, the thymus gland degenerates which leads to decreased production of thymosin hormone.
7. As a result old people have weak immune system and are more susceptible to infectious diseases.