Question

What are 10 facts on the circulatory system?

Answer 1

10. the hearts beats around 3 millions time in the averages persons life
2.it takes for about 20 seconds for a red blood cell to circle around the whole body
3. red blood cell make approximately 250,000 round trips of the body before returning to the bone marrow. where they were born
4.within a tiny droplets of blood there are some 5 millions red blood cells
5.about 8 million blood cell die in the human body every second and the same number are born
6. red blood cells may live for about 4 months circulating, thourought the body, feeding 60 trillions other body cells
7. your heart beats 70 times a minute
8. did you know that  in your life time your heart pumps enough blood to fill king size swimming pools?
9. you are heart beats faster when u re either scared, excited from running etc.
1. you are circulatory system is made up of the heart, blood, arteries, veins capillaries and blood cells. 
note: you are white blood cells do a major job eg: when germs come into ur body the white blood cells kills the germs, but for hiv is different caz white cells are weaker than the hiv virsues
hope i helped!