Hematology - the branch of medicine dealing with the study of the structure and function of the blood and blood-forming machine in norm and pathology. Hematology studies of cellular blood composition (morphological Hematology), the composition of plasma (serological Hematology), etiology, pathogenesis, clinical picture of the disease of the blood system, and develops methods of their diagnostics, treatment and prevention (of clinical Hematology). In addition, Hematology examines the reaction of the blood forming organs to defeat other body systems (such as infection), as well as various external effects on the body (radiation and others).