The Circulatory System Video (6min 14sec): https://www.youtube.com/watch?v=_eVG45_iF9U

The Circulatory System Composed of the blood, heart and blood vessels (arteries, veins and capillaries) It is responsible for transporting substances throughout the body It carries oxygen and nutrients to the cells and carbon dioxide and wastes away from cells

Blood Red blood cells contain a protein called hemoglobin which binds oxygen Hemoglobin contains iron, and when bound to oxygen makes the cells appear red

Blood White blood cells are part of the body’s immune system and are used to fight infection

The Heart The heart is the muscular organ that pumps blood to the cells and then back to the heart The heart contains four chambers – two upper chambers and two lower chambers The right side of the heart pumps blood to the lungs, the left side pumps blood to the rest of the body

Blood Vessels Make up the network of tubes that carry blood throughout the body Arteries carry blood away from the heart Veins carry blood to the heart

Blood Vessels Capillaries Smallest blood vessel Link veins are arteries together Point of gas exchange

Your turn Explain the function of the circulatory system. How does the circulatory system work together with the respiratory system An athlete measures how fast his heart is beating before and immediately after a race. What is likely to observe and why? Trace the path of blood, starting and finishing in the lungs.