Thymocytes normally mature and exit from the medulla or cortico-medullary junction but medullary migration is not necessarily a prerequisite for emigration.

Where does maturation of T cells occur?

Precursors of T cells migrate from the bone marrow and mature in the thymus.

Where do lymphocytes mature?

There are two major types of lymphocyte: B lymphocytes, which mature in the bone marrow; and T lymphocytes, which mature in the thymus. The bone marrow and thymus are thus known as the central or primary lymphoid organs.