Circulatory System Pt. 2
Just like a city with hallways and roads, your body has blood vessels, arteries and veins that help move things around. Most of the cells inside of your body do not move. If a cell is hungry or needs to get rid of waste, it can’t simply move itself to the part of your body where it needs to go.Instead, your body must bring the food to your cells and take the waste away from them.
Using billions of tiny tubes, your body is constantly pumping blood throughout your body. On the way out, your blood is loaded with the things that your body needs, like food, oxygen, and other chemicals. On the way back, your blood is full of things that the cells of your body need to get rid of, like waste.
What color is blood? Well, that depends.Sometimes it is red, and sometimes it is blue. Don’t believe me? Look at your arm. Better yet, look at the arm of one of your parents. Can you seethe blue veins? Why are they blue? When blood is full of oxygen it is red,but when it is low on oxygen it turns bluish. Why don’t I ever see blue blood? Because as it leaves your body it quickly turns red as it takes in oxygen.