explain immune system in body

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Immune system recognise the foreign antigen, responds to them and remember them.
The immune system also plays important role in

1. Allergic reactions
2. Auto immune disease and organ transplantation

In Our Body Immune System consist of : –

• Lymphoid organs
• Lymphoid tissue
• T and B- cells and
• Antibodies.

Primari lymphoid organs are bone marrow and thymus located near heat below breast bone. Secondary lymphoid organs are spleen, tonsil, lymph nodes etc.
Bone marrow is main lymphoid organ as all blood cell including lymphocytes are produced here.
Speen contain lymphocytes and phagocytes also serves as the large reservior of erythrocytes (RBC’s)