MICROANATOMY

Detailed explanation-1: -The greater part of lymphocyte development in mammals occurs in the specialized environments of the central lymphoid organs-the bone marrow (and the liver in the fetus) for B cells and the thymus for T cells.

Detailed explanation-2: -Enlarge. Anatomy of the thymus gland. The thymus gland is a small organ that lies in the upper chest under the breastbone. It makes white blood cells, called lymphocytes, which protect the body against infections.

Detailed explanation-3: -[1] The thymus is the organ primarily responsible for the production and maturation of immune cells; including small lymphocytes that protect the body against foreign antigens. The thymus is the source of cells that will live in the lymphoid tissues and supports their maturation and proper function.