Question

In what tissue do B and T-lymphocytes originate? What are the two steps involved in lymphocyte 'maturation'?

Answer 1

They originate in bone marrow, however T-lymphocytes mature in the thymus. The two steps are called positive selection and negative selection.

Answer 2

Bone marrows are the main source of B and T-lymphocytes. But T- lymphocytes can maturate in the thymus.

Thymus is a gland and you can find it in the mediastunum.

Basically, B- lymphocytes can maturates inside the bone marrows and flow with the bone marrows to enter the blood.

They follow two steps to reach the blood such as positive selection and negative selection.