1. T-Cell Maturation:
* The thymus is the primary site where T lymphocytes (T cells), a type of white blood cell, mature and differentiate.
* Immature T cells, called thymocytes, migrate from the bone marrow to the thymus.
* Inside the thymus, they undergo a rigorous selection process. This process eliminates T cells that might attack the body's own tissues (autoimmune response) and ensures that only T cells that can recognize and fight foreign invaders are released into the bloodstream.
2. Immune System Development:
* The thymus is essential for the development of a healthy immune system, capable of recognizing and destroying pathogens.
* It provides a safe environment for T cell development, away from potential threats.
3. Other Functions:
* The thymus also produces hormones like thymosin, thymopoietin, and thymulin, which play a role in T cell development and the overall immune response.
In a Fetal Pig:
The thymus is particularly prominent in fetal pigs, as it is essential for establishing a robust immune system before birth. The fetal pig will encounter a range of potential pathogens after birth, and its thymus ensures it has a functioning immune system to combat them.
Important Note:
The thymus gland is most active in early life. After puberty, its size gradually shrinks, and it becomes less active. This is normal and doesn't mean the immune system is compromised, as mature T cells generated during childhood continue to circulate in the body.