1. Movement of oxygen within the body

2. Movement of oxygen PULMONARY CIRCUIT (Lungs): PULMONARY CIRCUIT (Lungs): Blood enters the right atrium of the heart via the vena cava (major vein): Blood enters the right atrium of the heart via the vena cava (major vein): The blood is deoxygenated, and high in carbon dioxide The blood is deoxygenated, and high in carbon dioxide It is low in glucose and other nutrients; it is also high in urea, other nitrogenous wastes and various poisons. It is low in glucose and other nutrients; it is also high in urea, other nitrogenous wastes and various poisons. As the heart beats, the right ventricle pumps the blood through the pulmonary artery, to the lungs: As the heart beats, the right ventricle pumps the blood through the pulmonary artery, to the lungs: Here the blood gains oxygen, and loses its carbon dioxide. Here the blood gains oxygen, and loses its carbon dioxide. The blood then enters the left atrium via the pulmonary vein. The blood then enters the left atrium via the pulmonary vein.

3. Movement of oxygen SYSTEMIC CIRCUIT (Body): SYSTEMIC CIRCUIT (Body): The left ventricle pumps oxygenated blood to the body through the aorta. The left ventricle pumps oxygenated blood to the body through the aorta. In the body, various changes occur to the blood. In the body, various changes occur to the blood. The blood loses oxygen and gains carbon dioxide in all body cells, as respiration occurs. Glucose levels also drop. The blood loses oxygen and gains carbon dioxide in all body cells, as respiration occurs. Glucose levels also drop.

4. Oxygen in different organs In the LIVER: In the LIVER: Levels of glucose are regulated – excess glucose is changed to glycogen, or glycogen stores are changed to glucose (if needed) Levels of glucose are regulated – excess glucose is changed to glycogen, or glycogen stores are changed to glucose (if needed) Excess amino acids are changed to ammonia, and then to urea Excess amino acids are changed to ammonia, and then to urea Poisons are also reduced, as the liver changes them to less toxic forms Poisons are also reduced, as the liver changes them to less toxic forms In the INTESTINES: In the INTESTINES: Levels of nutrients from digestion increase. Levels of nutrients from digestion increase. Glucose, amino acids, ions, lipids and other substances from food enter the blood. The increase is through the small intestines reabsorption of food Glucose, amino acids, ions, lipids and other substances from food enter the blood. The increase is through the small intestines reabsorption of food In the KIDNEYS: In the KIDNEYS: Salt and water levels are regulated Salt and water levels are regulated All urea is removed, toxins are excreted into the urine All urea is removed, toxins are excreted into the urine The changed blood, again highly deoxygenated, then flows back to the pulmonary circuit. The changed blood, again highly deoxygenated, then flows back to the pulmonary circuit. need for removal of carbon dioxide need for removal of carbon dioxide

5. Explain why the removal of carbon dioxide from cells is essential All living cells need oxygen for respiration. All living cells need oxygen for respiration. As a result of respiration, carbon dioxide is produced As a result of respiration, carbon dioxide is produced When carbon dioxide dissolves in water, it makes carbonic acid. When carbon dioxide dissolves in water, it makes carbonic acid. This means that if a lot of carbon dioxide is produced, the body cells (and the blood and lymph) will become acidic. This means that if a lot of carbon dioxide is produced, the body cells (and the blood and lymph) will become acidic. As studied before, enzymes can only function within a specific pH range As studied before, enzymes can only function within a specific pH range So an increase in carbon dioxide will result in a lowering of pH, which will affect the overall metabolism of the body. So an increase in carbon dioxide will result in a lowering of pH, which will affect the overall metabolism of the body.