Chapter 2 : The heart
– – – Ask to the children to give all the words which remind them in heart. To show the drawing of the heart has real size. (Appendix 1) Give in synthesis of the activity a definition.

The heart, it's a muscle which is in the left at the middle of our breast. We say that our heart beats because it contracts and loosens all day long to cleanse the blood and propel it in the body. Indeed, it gets back the blood full of waste and transforms it into a blood rich in oxygen and nutrients. It's an indispensable muscle to the life.

I- The general organization of the heart: its various compartments.
– Describe the various compartments by means of a plan. (Appendix 2) – Make complete the legends and color the plan by the pupils. The heart is composed of four compartments. Left atrium is connected with the left ventricle and right atrium is connected with the right ventricle on the other side. Running down the middle of the heart is a thick wall of muscle. Atria are situated on the top of the heart and ventricles are in the bottom. Every compartment is opened towards the body thanks to the vessels which are transport the blood. Veins bring the blood to the heart and arteries leads the blood to the body. There are small valves in the entrance of the blood vessels which prevent the blood from returning behind.

II- The route of the blood (= the blood circulation)

– Explain to the pupils by means of the plan. (Appendix 3) – Activity: take louse. Having gone out of the left ventricle by a strong pressure of the heart, the blood go in the body by the aorta. It delivers then the oxygen and the nutriments to the cells of all our organs (muscles, bowel, brain). They need blood to grow up and assure the functions of our body. When cells use the oxygen, they make carbon dioxide ( CO2) which is bad for our body. The CO2 is then taken by the blood until the right part of the heart. It's the vena cava which assures this work. The blood enters by the