what are the two main types of lymphocytes quizlet?
['T cells. thymus dependent circulating lymphocytes, make up 80% of circulating lymphocytes.', 'B cells. bone marrow-derived circulating lymphocytes, make up 10-15% of circulating lymphocytes.', 'NK cells. ... ', 'cytotoxic T cells. ... ', 'helper T cells. ... ', 'suppressor T cells. ... ', 'memory T cells. ... ', 'plasma cells.']