In an average healthy adult, approximately how much total blood volume is contained in the body?

• A. About 20 liters (approximately 18–22 L)
• B. About 10 liters (approximately 9–11 L)
• C. About 1 liter (approximately 0.5–1.5 L)
• D. About 5 liters (approximately 4.5–6.0 L)

Answer: (D)

Verified step by step guidance

1. Understand that the total blood volume in an average healthy adult is a physiological parameter that varies based on factors such as body size, sex, and overall health.
2. Recall that typical blood volume is often estimated as a proportion of body weight, commonly around 7-8% of total body weight in kilograms.
3. Use the formula for estimating blood volume: \(\text{Blood Volume} = \text{Body Weight} \times \text{Average Blood Volume per kg}\), where average blood volume per kg is approximately 70-80 mL/kg.
4. Recognize that for an average adult weighing about 70 kg, multiplying by 70-80 mL/kg results in a total blood volume close to 5 liters.
5. Conclude that the approximate total blood volume in an average healthy adult is about 5 liters, which aligns with the typical physiological range of 4.5 to 6.0 liters.