1. The Excretory System Excretion- The process by which the waste of cellular metabolism are removed Excretory organs regulate the chemical makeup of blood and other body fluids Helps maintain stable body temperature Excretion is not elimination

2. Major Organs of Excretory System LungsLiverSkinKidneys

3. Lungs CO 2 & water vapor are waste products of cellular respiration that are eliminated from the body when we exhale

4. Liver Provides a number of excretory functions Detoxification: Removes harmful & toxic substances from the blood Detoxification: Removes harmful & toxic substances from the blood Excretion of Bile: Bile is reused by the liver, if bile cannot be reused it is eliminated in feces Excretion of Bile: Bile is reused by the liver, if bile cannot be reused it is eliminated in feces Urea Formation: Process by which ammonia is transformed into urea so it can be eliminated later. Comes from the breakdown of amino acids Urea Formation: Process by which ammonia is transformed into urea so it can be eliminated later. Comes from the breakdown of amino acids

5. Skin Sweat is released through pores in the skin Sweat is a mixture of water, salts & urea Sweating excretes metabolic wastes & has a cooling effect on the body

6. Kidneys Three of the four major metabolic wastes produced by the body are filtered from the blood by the kidneys Water Water Salts Salts Urea Urea

7. Urinary System

8. Includes: Kidneys, bladder & ducts Kidneys: remove wastes of cellular metabolism & control the amount of various substances in the blood Functional unit of kidney is the nephron Functional unit of kidney is the nephron Bladder: Temporary storage of urine Urethra: Tube that carries urine from the bladder out of the body