Table of Contents Track and Field Events Warming up Training Training Tips Cells and Bones Joints and Muscles Movement and Muscle Fibers Energy Production in the Body The Cardio-respiratory System Nutrition and Calories Nutrients, Proteins and Carbohydrates Fats, Vitamins, Minerals, Water and Fiber Record Breakers Did you know? (Cool Track Facts) Track and Field Links Bibliography Chimacum Middle School ThinkQuest Jr. Please give us Feedback about our site. Contact us! Meet the Team Featured site: The International Amateur Athletics Federation

Around the Track and Back Anatomy and Phisiology Basics, cont'd: Getting oxygen to muscles The cardio-respiratory system is responsible for getting oxygen to the muscles. It is also used to remove waste from the muscles. It consists of the lungs, heart, blood vessels and blood. The lungs get oxygen into the blood from the air we breathe. At rest, one can breathe about 10 liters of air every minute. During hard exercising, one can breathe up to 120 to 150 liters per minute. One can only breathe about 50 liters per minute through the nose so athletes should breathe through an open mouth. Human Lungs The Heart The heart is a muscle that pumps blood throughout our body all the time, it doesn't stop from before we're born until we die. When the heart contracts, it is called a heartbeat. When exercising, the muscles need more oxygen so the heart beats faster to pump more oxyenated blood to them. Oxygenated blood is just blood that is carrying oxygen. Training increases the size, thickness, and strength of the heart muscle so that it can work more efficiently. The Human Heart Blood and blood vessels Blood travels through a network of tubes in the body called blood vessels. Arteries are blood vessels that carry blood away from the heart and veins are blood vessels that carry blood to the heart. So when we take a breath of air, the lungs transfer oxygen from the air into blood cells in veins. This oxygenated blood is carried to the heart where it gets pumped into arteries that take the oxygenated blood to the muscles. The blood transfers oxygen to the muscles so they can keep working and the blood takes waste from the muscles. This oxygen poor blood, blood without oxygen and with wastes, goes into a vein to return to the heart where it gets pumped back to the lungs to get more oxygen. Wastes are taken to the kidneys while carbon dioxide is taken to the lungs. The carbon dioxide is waste so we breathe it out everytime we exhale.