X Her brotherâs illness forced her to explore feelings that had lied dormant for some time. â â¦. that had lain dormantâ¦ [past perfect of lie (1)]. X I laid down on my bed and went to sleep. â I lay down on my bedâ¦ [simple past of lie (1)]. X Sheâs laying flat on her back, out for the count. â Sheâs lying flat on her backâ¦ [present continuous of lie (1)]. X When she died, she was lain in an ornate wooden coffin. â â¦she was laid in an ornate wooden coffin.
The receptors match only one specific antigen. White blood cells called lymphocytes originate in the bone marrow but migrate to parts of the lymphatic system such as the lymph nodes, spleen, and thymus. There are two main types of lymphatic cells, T cells and B cells.he receptors match only one specific antigen. White blood cells called lymphocytes originate in the bone marrow but migrate to parts of the lymphatic system such as the lymph nodes, spleen, and thymus. There are two main types of lymphatic cells, T cells and B cells.
Antigens are chemicals on the surface of a cell. All cells have these. The immune system checks cells and identifies them as self or non-self. Antibodies are proteins produced by certain lymphocytes in response to a specific antigen.B-lymphocytes and T-lymphocytes produce the antibodies. B-lymphocytes become plasma cells which then generate antibodies. T-lymphocytes attack cells which bear antigens they recognize.ome lymphocytes migrate to the thymus and become T cells that circulate in the blood and are associated with the lymph nodes and spleen. B cells remain in the bone marrow and develop before moving into the circulatory and lymph systems. B cells produce antibodies. Macrophage Attacking E.coli (SEM x8,800).