THE LAND: Afghanistan is known for it's mountainous terrain. The huge Hindu Kush mountains form a barrier between the Northern provinces and the rest of the country. This mountain range has also divided Afghanistan int three very different geographic regions known as; The Central Highlands, The Northern Plains, and the Southwestern Plateau.
â Antibody producing B cells develop into plasma cells â¢ Plasma cells only found in lymphoid organs, not in general circulation or lymph â¢ eccentric nuclei and perinuclear halo (clear region under nucleus) â Clonal expansion leads to development of effector cells or memory cells for both T and B events. Memory cells can survive 20 years or
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. cells can also produce memory cells with an even longer life span than B memory cells. The second time an intruder tries to invade the body, B and T memory cells help the immune system to activate much faster. The invaders are wiped out before the infected human feels any symptoms.