Yuyen T.Mahidol University2023-06-182023-06-182022-01-01Transfusion Practice in Clinical Neurosciences (2022) , 249-255https://repository.li.mahidol.ac.th/handle/20.500.14594/86211Blood is a fluid connective tissue circulating through blood vessels. There are two components in the blood, fluid component (plasma) and cellular elements (red blood cells, white blood cells, and platelets). Each of the components plays different roles which in summation provide various functions of the blood including transportation of gases, nutrients, wastes, hormones, etc., defense against invading microorganisms, maintenance of homeostasis, and distribution of heat. This article gives basic information about the component of blood and how to estimate blood volume. The various functions of blood are also described. Understanding this knowledge is helpful for physicians in order to offer a safe and effective care to the patients.MedicineBook ChapterSCOPUS10.1007/978-981-19-0954-2_242-s2.0-85160792017