Where do T lymphocytes originate?

Where do T lymphocytes originate?

• A. Bone marrow
• B. Thymus
• C. Spleen
• D. Lymph node

Answer: (A)

The main concept is that T lymphocytes originate from hematopoietic stem cells in the bone marrow. From there, these cells become common lymphoid progenitors that travel to the thymus, where they mature into T cells through processes like T cell receptor gene rearrangement and educational selection. The thymus is the site of maturation and education, not the origin. Once mature, T cells reside in secondary lymphoid organs such as the spleen and lymph nodes to participate in immune responses. So, the starting point for T cell origin is the bone marrow, with maturation occurring in the thymus.

The main concept is that T lymphocytes originate from hematopoietic stem cells in the bone marrow. From there, these cells become common lymphoid progenitors that travel to the thymus, where they mature into T cells through processes like T cell receptor gene rearrangement and educational selection. The thymus is the site of maturation and education, not the origin. Once mature, T cells reside in secondary lymphoid organs such as the spleen and lymph nodes to participate in immune responses. So, the starting point for T cell origin is the bone marrow, with maturation occurring in the thymus.