What is the normal plasma volume of a 70kg adult man?

The normal plasma volume of a 70 kg adult man is approximately 5 liters. Plasma volume is a key component of total blood volume, which in an average adult typically constitutes about 55% of the total blood volume. Given that the average total blood volume for an adult is around 70 mL per kg, a 70 kg individual would have a total blood volume of approximately 4.9 to 5.0 liters of plasma. Therefore, this choice aligns with physiological standards, making it the correct answer.

This estimation reflects the important role of plasma in carrying nutrients, hormones, and proteins throughout the body, as well as regulating blood pressure and blood volume. In clinical practice and studies of cardiovascular health, understanding the normal values for plasma volume is crucial for assessing patient conditions and guiding treatment.