Leukocytes are the white blood cells that are found in connective tissue. Watch this video if you want to learn how to identify different types of leukocytes present on a histological section. Timeline: 00:00 introduction 00:24 eosinophils 01:09 neutrophils 01:29 lymphocytes 02:03 plasma cells 02:45 lymphocytes 03:45 leukocytes in appendicitis 05:01 macrophage 05:58 macrophages in lymph node infection