Elimination of Wastes Carbon Dioxide and Nitrogenous Wastes

Carbon Dioxide Produced by the metabolism of foods by our cells Produced by the metabolism of foods by our cells Pathway of CO 2 in the body Pathway of CO 2 in the body –Diffuses from the cells into the blood –Is carried by the plasma and RBC to the lungs –Diffuses from the blood into the lungs –Leaves the body

The lungs have two major roles in the body The lungs have two major roles in the body –Remove carbon dioxide –Replenished oxygen –Their ability to do these two important functions are affected by:  Being overweight  Poor physical health  Tobacco or drug use

Respiratory Rate Your respiratory rate will vary depending on your level of physical activity Your respiratory rate will vary depending on your level of physical activity –The rate slows when you are at rest –It speeds up when you are active and the body needs more oxygen brought in AND needs more carbon dioxide removed

Cellular respiration, carbon dioxide level and respiratory rate during strenuous exercise: 1. Increased demand for energy 2. Cells metabolize nutrients faster (waste product is CO 2 ) 3. More carbon dioxide will be produced by the cells and this will enter the blood.

4. The medulla oblongata will detect the higher levels of CO 2 in the blood and it will tell the chest cavity to increase respiration 5. The CO 2 will be expelled from the lungs at a rate that is proportional to its concentration in the blood (heavy breathing)

It is the increased levels of carbon dioxide in the blood that increases your respiratory rate NOT the lack of oxygen. It is the increased levels of carbon dioxide in the blood that increases your respiratory rate NOT the lack of oxygen. Review Questions page 208:1 to 8

Renal Excretory System Removes nitrogenous waste from the blood Removes nitrogenous waste from the blood These waste are produced when protein is broken down by the body These waste are produced when protein is broken down by the body A small amount of the nitrogenous waste will be excreted from the body by sweating. A small amount of the nitrogenous waste will be excreted from the body by sweating.

Parts of the Renal Excretory System 1) The kidneys 2) The bladder 3) The ureters 4) The urethra

Function of the Kidneys The kidneys filter the blood The kidneys filter the blood The main functional unit (where the work is done) is the nephron The main functional unit (where the work is done) is the nephron Each kidney has nearly one million nephrons Each kidney has nearly one million nephrons The nephrons are in the outer layer of the kidney The nephrons are in the outer layer of the kidney

Blood enters the kidney by the renal artery. Blood enters the kidney by the renal artery. –The kidney removes wastes and any other substances in excess in the blood –The wastes leave the kidneys through the ureters Purified blood leaves the kidney by the renal vein. Purified blood leaves the kidney by the renal vein.

Stats about your kidneys: Filter 180 litres of blood per day Filter 180 litres of blood per day Produce 1 to 1.5 litres of urine Produce 1 to 1.5 litres of urine Some of the water removed by the kidneys will be reabsorbed in the renal veins. This is to counter water lose through sweating. Some of the water removed by the kidneys will be reabsorbed in the renal veins. This is to counter water lose through sweating.

Substances removed by the kidneys: Water Water Urea Urea Uric acid Uric acid Minerals Minerals Yellow pigments Yellow pigments

The following are not normally removed by your kidneys and are a sign of trouble: The following are not normally removed by your kidneys and are a sign of trouble: –Glucose –Red blood cells –Protein See your doctor!!!!

Normal components of purified blood: Normal components of purified blood: –RBC –WBC –Platelets –Lipids –Carbs –Protein –Water and minerals

Path of Nitrogenous Wastes: Produced by the cells as protein is metabolized Produced by the cells as protein is metabolized Passed into the bloodstream Passed into the bloodstream Taken to the kidneys and removed from the blood Taken to the kidneys and removed from the blood Ureters carry urine from kidneys to bladder Ureters carry urine from kidneys to bladder Travel from the bladder through the urethra and out of the body Travel from the bladder through the urethra and out of the body

Factors Affecting the Quantity of Urine The amount of water intake The amount of water intake The type of food eaten The type of food eaten The amount of water lost by perspiration The amount of water lost by perspiration

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