what is a hematocrit? blood quizlet?
<answer> A hematocrit is a test that measures the proportion of a person's blood that is made up of red blood cells. <context> A hematocrit is a test that measures the proportion of a person's blood that is made up of red blood cells (RBCs). Blood consists of RBCs, white blood cells (WBCs), and platelets suspended in a fluid portion called plasma. The hematocrit is a ratio of the volume of red blood cells to the volume of all these components together, called whole blood. The value is expressed as a percentage or fraction. For example, a hematocrit value of 40% means that there are 40 milliliters of red blood cells in 100 milliliters of blood. The hematocrit is a fairly quick and simple way of evaluating a person's red blood cells and checking for conditions such as anemia.