In a typical healthy adult, approximately how much total blood volume does the human body contain?

• A. About 30 liters (roughly 25–35 L)
• B. About 5 liters (roughly 4–6 L)
• C. About 15 liters (roughly 12–18 L)
• D. About 0.5 liters (roughly 0.3–0.7 L)

Answer: (B)

Verified step by step guidance

1. Understand that the total blood volume in a typical healthy adult is the amount of blood circulating within the entire cardiovascular system, including arteries, veins, and capillaries.
2. Recall that blood volume is generally proportional to body size and weight, but for an average adult, it falls within a standard range.
3. Recognize that the commonly accepted average blood volume for a healthy adult is approximately 7-8% of their total body weight.
4. Use the average adult body weight (around 70 kg) to estimate blood volume by calculating 7-8% of 70 kg, which gives a volume in kilograms that can be converted to liters (since 1 kg of blood roughly equals 1 liter).
5. Conclude that this calculation leads to an approximate blood volume of about 5 liters, which aligns with the typical physiological range of 4 to 6 liters for a healthy adult.