How does your heart work? Lesson 14 How does your heart work?

Place your hand on your chest. What do you feel? Your heart beats nonstop for your whole life, keeping you alive. It pumps blood to all parts of your body. Have the kids feel their heartbeat.

The human heart is divided into four separate spaces called chambers. Two chambers are in the upper part of the heart; two chambers are in the lower part of the heart. Notes: Heart has 4 chambers, two upper and two lower.

There is a right and left atrium. Atria are the upper chambers of the heart. A single atria is called an atrium. There is a right and left atrium. Notes: Atria: upper chambers Atrium: one atria Atria receive blood.

Point out each part

The right atrium receives blood from all parts of the body. This blood is high in carbon dioxide and low in oxygen Notes: All

The left atrium receives blood from the lungs. This blood is high in oxygen and low in carbon dioxide. Notes: All

Both atria fill with blood at the same time!!!!! Notes: All

The right ventricle pumps blood to the lungs. Ventricles: are the lower chambers of the heart. They pump blood out of the heart. The right ventricle pumps blood to the lungs. Notes: All This blood is high in carbon dioxide and low in oxygen.

In the lungs, the blood gives up its carbon dioxide and takes in oxygen. The left ventricle pumps blood to all parts of the body except the lungs. Notes: all

Both ventricles pump blood out of the heart at the same time. Blood in the left ventricle is high in oxygen and low in carbon dioxide. Both ventricles pump blood out of the heart at the same time. Notes: all

Blood moves in only one direction only. Every time your heart beats, blood is “squeezed” out of the ventricles. Blood moves in only one direction only. The heart and veins have valves that keep blood from moving backwards. Notes: Blood moves in only one direction Heart and vein valves keep blood from moving backwards.

A valve is a flap of tissue that works like a one way swinging door. The septum is a thick muscular wall that separates the two sides of the heart. Blood can not flow from one side to the other. Notes: all