How does the circulatory system work part 2 activity mix and match worksheet?

The circulatory system works by pumping blood to the body through the arteries 

We can describe the human circulatory system as "Double circulation".

The three main blood vessels in our body help transport blood. Artery, which transports blood away from the heart to other organs; veins, which transport blood from other organs back to the heart; and capillaries, which allows substances exchange in organs. 

The heart is composed of 4 chambers. Left and right atrium and ventricle.  Let's trace the path of a drop of blood. First, the blood starts off with being deoxygenated and full of waste like carbon dioxide. It arrives the right atrium from other organs through the vena cava (vein). The heart then relaxes and the blood goes to the right ventricle. When the heart contracts again, the blood is forced out and is now being transported to the lungs, by the Pulmonary artery. In the lungs, gas exchange takes place. Carbon dioxide diffuses out from the blood and new oxygen diffuses in. Now the blood is oxygenated and full of nutrients. Then, the blood is traveled back to the heart, through the Pulmonary vein, to the left atrium. Again, then to left ventricle and getting forced out of the heart. Now, the blood is being transported to all the other organs (except lungs) to provide oxygen and nutrient to the organs to function. And of course, there it goes again, back to the right atrium through the vena cava.

That's why we call our human circulation a double circulation, as the same blood has to travel to the heart twice before starting the cycle again. 

By water evaporation from the leaves is created a negative pressure at the top of the tree that promotes the ascension  of the water through channels that are called xylem. there are also two molecule forces that are involved: the intra-water molecules cohesion (water molecules stick to each other) and the adhesion when the water molecules stick to the channels they are running in. this is what enables water to go from the roots to the top of a tall tree.