Why is blood needed by all the parts of a body?

The blood from the heart is transported to all parts of the body by the______.

Statement 1: Atria receive blood from all parts of the body which subsequently flows to ventricles. Statement 2: Action potential generated at sino-atrial node passes from atria to ventricles.

Name the process through which much needed oxygen is supplied to all the cells of body ?

Fill in the blanks of the following paragraph using just two words – arteries and veins ___(a)___ carry oxygen-rich blood from the heart to all parts of the body and ___ (b)___ carry carbon dioxide-rich blood from all parts of the body back to the heart. ___ (c)___ have thin walls and __ (d)___ have thick elastic walls. Blood flows at high pressure in ___ (e)____. Valves are present in __ (f) ___ which allow blood to flow only towards the heart. __ (g)___ divide into smaller vessels. These vessels further divide into extremely thin tubes called capillaries. The capillaries join up to form __________ .

__________ circulates blood to different parts of the body .