The Japanese word for Japan is æ¥æ¬, which is pronounced Nippon or Nihon and literally means the origin of the sun. The earliest record of the name Nihon appears in the Chinese historical records of the Tang dynasty, the Old Book of Tang.
The secondary immune response occurs the second time (3rd, 4th, etc.) the person is exposed to the same antigen. At this point immunological memory has been established and the immune system can start making antibodies immediately.
These cells enable the immune system to recognize antigens that the body has previously encountered. Memory cells direct a secondary immune response in which antibodies and immune cells, such as cytotoxic T cells, are produced more quickly and for a longer period of time than during the primary response.