In a healthy adult, plasma normally makes up what percentage of whole blood volume?

• A. About 55%
• B. About 75%
• C. About 45%
• D. About 25%

Answer: (A)

Verified step by step guidance

1. Understand that whole blood is composed of plasma and formed elements (such as red blood cells, white blood cells, and platelets).
2. Recall that plasma is the liquid component of blood, primarily made up of water, proteins, electrolytes, and other substances.
3. Recognize that in a healthy adult, plasma typically constitutes the majority of the blood volume compared to the formed elements.
4. Remember the standard percentage range for plasma volume in whole blood, which is commonly around 55%.
5. Compare the given options to this known value to identify that 'About 55%' is the correct percentage of plasma in whole blood volume.