Understanding Hematocrit: The Percentage of Blood Volume Occupied by Erythrocytes

What is the percentage of blood volume occupied by erythrocytes called?

1) buffy coat
2) hematocrit
3) blood volume
4) hemostat

Answer:

The hematocrit is the percentage of blood volume occupied by erythrocytes.

The percentage of blood volume occupied by erythrocytes, also known as red blood cells (RBCs), is called the hematocrit. A hematocrit test measures this percentage by centrifuging a blood sample, which causes erythrocytes to settle at the bottom. The volume they occupy, shown as a percentage, reflects the hematocrit. With normal values ranging approximately from 36 to 50 percent, differentiation in hematocrit can occur based on gender and other factors.

In contrast, the buffy coat, which includes white blood cells (leukocytes) and platelets (thrombocytes), usually constitutes less than 1 percent of a blood sample, sitting above the erythrocytes layer and beneath the plasma. The plasma forms the remaining volume of the blood sample.