This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Circulation, Subject name: Physiology
The percentage of blood that is present in capillaries is: 
Select and explain. 
A. 5%, B. 10%, C. 15%, D. 20%
A: 5%
Answer: A: 5% 
Explanation: At any given time: 54% of the total blood volume is contained within the venous compament; 10% in the aoa and aeries, 5% in the capillaries, 1% in the aerioles, 12% blood volume in the hea and 18% in the pulmonary circulation.