4 The Circulatory System

THE CIRCULATORY SYSTEM

INTRODUCTION Your body is made up of millions of tiny living things called cells. Each of these cells needs oxygen and nutrients from food to keep you alive! Blood delivers oxygen and nutrients to your cells. But if it weren't for ME, your blood wouldn't go anywhere! I'M YOUR HEART!

I pump blood into a network of tubes called blood vessels. Together, the heart, blood vessels, and blood make up the circulatory system. HOP Plop The circulatory system carries blood to every part of your body, from your head to your toes! Let's take a closer look...

WHAT IS BLOOD? Blood is like a river of life flowing through your body. MMM! It supplies cells with oxygen and nutrients... ...and carries away wastes that cells produce. THANK YOU! My pleasure!

More than half of your blood is made of a watery, pale-yellow liquid called plasma. Blood also contains three different types of blood cells: RED BLOOD CELLS PLATELETS WHITE BLOOD CELLS Plasma carries these blood cells through blood vessels.

RED BLOOD CELLS Each type of blood cell has a different job. Yet, each job is just as important as the other! Red blood cells transport oxygen throughout your body. Red blood cells are so small you could fit millions of them in this panel! In addition to being small, red blood cells are also pliable. They easily compress and stretch to fit through even the narrowest blood vessel.