1. The Respiratory System  Its job is to deliver oxygen to all cells in the body and to get rid of CO2. • Movement of the chest when breathing is caused by the movement of the diaphragm. • Diaphragm: is the muscle that allows human to inhale and exhale.

2. The Respiratory System  Main parts of respiratory system: • Mouth and nose: allows the body to inhale oxygen. • Trachea. • Bronchi. • Lungs. • In the lungs, the tube end in tiny air sacs, which allow gases move through them.

3. The Respiratory System • Oxygen from the air moves to the heart; which pumps blood with oxygen to all parts of the body. • CO2 is carried from the cells to the air sacs of the lung. It then leaves the body when you exhale.

4. The Circulatory System • Blood moves from the heart and returns back to it through blood vessels. • Artery: is a blood vessel that carries blood away from the heart. • Vein: is a blood vessel that returns blood to the heart. • Capillary: is a blood vessel with very thin walls that allow oxygen and CO2 to pass through.

5. Heart

6. Blood • Blood is a liquid form of connective tissue. • Blood contains different types of cells that move in a liquid called plasma.

7. Blood • Types of blood cells are: • 1. Red blood cells: They carry oxygen to all • of the body’s cells. • 2. White blood cells: protect the body from germs. • 3. Platelets: function to make clots and stop bleeding in case of a cut.