2 What does it do? Every cell produces metabolic wastes such as: Salt Carbon dioxideUrea (toxic compound produced when making energy)The excretory system’s job is to remove these useless and harmful wastes from the body.
3 The Organs The main organs of the excretory system are: KidneysSKINLungsskin covers and protects your bodylungs located in chest and protected by ribcagekidneys found on either side of backbone and about the size of a fist
4 Kidneys StructureMade of Inner (renal medulla) and outer (renal cortex)The functional units of the kidney are nephronsEach nephron has its own bloodsupply through the use of 4 parts.Ateriole :: Where the blood entersCapillaries :: FiltrationCollecting duct :: Waste from blood ends up here which leads to ureterVenule :: Where the purified blood exits
5 Blood PurificationIt is broken into three processes: filtration, reabsorption, and secretion.Filtration:: Blood enters nephron and flows into theglomerulus, a small network of capillaries isheld in the upper end of the nephron by Bowman’scapsules:: Because the blood is under pressure and thecapillaries are permeable fluid flows into Bowman’scapsule:: The filtrate (filtered materials) contains water, urea, glucose, salts, amino acids, and some vitamins
6 Blood Purification Reabsorption Filtration, reabsorption, and secretionanimationReabsorption:: Most material removed from the bloodgoes back into the blood throughreabsorption:: The nutrients are taken out of the filtratewith active transport and then put backin the bloodSecretion:: The cells of the tubules remove certain molecules and ions from the blood and deposite these into the fluid within the tubules.: Tubular secretion of H+- is important in maintaining control of the pH of the blood..
7 Urinary system Urine is the material that remains after reabsorption It is concentrated in the loop of Henle where water is conserved and the volume of urine minimizedUrine is collected in the urinary bladderwhile purified blood goes back into normalcirculationUrine is released through the urethratube
8 The Kidneys and Homeostasis :: The kidneys regulate water content in the blood, which controls blood volume, pH, and waste in the blood.:: How do they do it?Liquid that you consume goesinto the bloodThis increased concentration shouldforce water into cells, swelling your bodyHowever the kidneys control this bylowering the rate of reabsorption of waterAs for salt, the more you eat,the less that is returned to the blood
9 Skin and Lungs Skin excretes waste products from the body through perspirationThis includes water, salt, and a smallamount of urea and other toxic substancesThe lungs excrete carbondioxide during respirationCO2 is produced whenenergy is taken from foodSimple breathing animation >>>>>>>Blue: oxygen, purple: CO2
10 When something goes wrong… The major disease to the excretory system is kidney diseaseThis can lead to kidney failure, and the inability to remove waste productsMany kidney problems can be treated by dialysis, where a machine acts as a kidney. However, it is very expensive and time consuming. Kidney transplants are an alternative to dialysis.Dialysis Animation:: Medical science is workingon developing an artificialkidney transplant for the future!
11 A Healthy Excretory System As with all of your body systems eating well promotes a healthy excretory system, especially getting enough dietary fiberDiabetic kidney disease can be prevented by keeping blood sugar in your target rangeFor more information visit:(kidney disease)(detailed explanation of reabsorption)(overview)