In a typical healthy adult, approximately what percentage of whole blood volume is composed of plasma?

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

Answer: (D)

Verified step by step guidance

1. Understand that whole blood is composed of two main components: plasma and formed elements (such as red blood cells, white blood cells, and platelets).
2. Recall that plasma is the liquid portion of blood, which carries nutrients, hormones, and waste products, and typically makes up the majority of blood volume.
3. Remember the typical percentage ranges for blood components in a healthy adult: plasma usually accounts for about 55% of the total blood volume, while the formed elements make up the remaining 45%.
4. Recognize that the given options (75%, 45%, 25%) do not match the typical plasma percentage, but 55% is the accepted average value for plasma volume in whole blood.
5. Conclude that the correct answer is approximately 55%, reflecting the typical plasma proportion in whole blood volume for a healthy adult.