Dr. Y. Thangam working as an Assistant Professor, PG & Research Dept of Zoology at J.K.K.N. For human body the hormones, glands and enzymes plays an important role. In this research the organs, toxicity and immunity were discussed. Systems-Endocrine, Exocrine , Nervous, Muscular, Circulatory, Respiratory, Digestive, Lymphatic, Skeletal, Excretory.