Final answer:
The hematocrit measures the percentage of erythrocytes (red blood cells) in a given volume of whole blood. It is determined by spinning a blood sample in a centrifuge, causing the heavier erythrocytes to settle at the bottom. The test helps assess blood composition and diagnose certain conditions.
Step-by-step explanation:
The hematocrit measures the percentage of erythrocytes (red blood cells) in a given volume of whole blood. It is determined by spinning a blood sample in a centrifuge, causing the heavier erythrocytes to settle at the bottom, while the remaining formed elements of blood, such as leukocytes (white blood cells) and platelets, form a pale layer above the erythrocytes.
In normal blood, approximately 45 percent of a sample is made up of erythrocytes. The hematocrit value can vary within the range of 36-50 percent, depending on factors such as gender and other individual characteristics.
The hematocrit test is important for assessing blood composition and can help diagnose conditions such as anemia or polycythemia.