Human Excretory System Topic 16

Excretion Urea The process of removing metabolic wastes Metabolic waste formed by deamination of proteins (breaking down amino acids) in the liver

The KIDNEYS Filter wastes from the blood Nephrons make urine from wastes Fun Fact: Each kidney has about 1.25 million nephrons! Image: http://www.nlm.nih.gov/medlineplus/ency/imagepages/1101.htm

The KIDNEYS Substances needed by body are reabsorbed and return to the blood (water by osmosis, other materials by active transport!) Salts, urea & excess water form Urine Fun Fact: about 99% of water is reabsorbed!

How Kidneys Work http://www.youtube.com/watch?v=TzwPmz5V6Xg Image: http://bryanking.net/disorders-of-the-kidney/

The URINARY SYSTEM Urine formed in Kidneys Ureters- bring urine to the urinary bladder Urinary Bladder- stores urine Urethra- tube which carries urine out of the body

Image: http://kidney.niddk.nih.gov/kudiseases/pubs/yoururinary/

Malfunctions of the Excretory System Kidney Stones: High levels of Uric Acid & calcium crystallize Very painful Must pass stones or have them removed Image: http://www.symptoms-kidney-stones-treatments.com/kidney-stone-surgery.html

Image Courtesy of B. Beck Kidney Stone in X-Ray Image Courtesy of B. Beck

Organs of the Human Excretory System Lungs CO2 & Water from Cellular Respiration Liver Deamination- break down proteins Kidneys Water, Salts, Urea Skin

The SKIN

The SKIN Sweating cools the body Sweat excretes water, salts & urea Maintains HOMEOSTASIS Images: Microsoft Clip Art

Brain Pop: http://www.brainpop.com/health/bodysystems/urinarysystem/