In a typical healthy adult, the formed elements (erythrocytes, leukocytes, and platelets) make up approximately what percentage of whole blood volume?

• A. 95%
• B. 55%
• C. 5%
• D. 45%

Answer: (D)

Verified step by step guidance

1. Understand that whole blood is composed of two main components: plasma and formed elements. Plasma is the liquid portion, while formed elements include erythrocytes (red blood cells), leukocytes (white blood cells), and platelets.
2. Recall that in a typical healthy adult, plasma makes up about 55% of the total blood volume. This means the remaining percentage is made up by the formed elements.
3. Since plasma is approximately 55%, subtract this percentage from 100% to find the percentage of formed elements in whole blood: \$100\% - 55\%$.
4. Calculate the difference to determine the approximate percentage of formed elements in whole blood volume.
5. Recognize that the formed elements typically make up about 45% of the whole blood volume, which is also known as the hematocrit value.