1. Excretory

2. Function Remove metabolic waste from the blood- Excretion Regulate H2O in blood Organs of excretion- Skin-water, salts and urea Lungs-CO2 Kidneys Hormones regulate filtration and excretion.

3. 4 Parts Kidney: filters blood to remove metabolic waste Maintains homeostasis of body fluids Maintains body PH Regulates water in blood volume Ureter: takes urine from kidney to bladder Bladder: stores urine (sterile environment) Urethra: takes urine outside of the body

4. Parts of the Kidney Renal medulla- inner layer of the kidney Renal Cortex- Outer layer of the kidney Renal artery- brings contaminated blood into the kidney Renal vein- brings clean blood away from kidney Nephrons- Functional units of the kidneys that filters the blood

5. Nephrons Each kidney has about 1 million nephrons Nephrons are located in renal cortex with part extending into the medulla Work by filtrating the blood, reabsorbing substances and excreting waste Each nephron has it’s own arteriole and venule.

6. Glomerulus and Bowman’s Capsule Filtration takes place in Glomerulus. Network of capillaries under pressure, Liquid part of blood is filtered Except RBC, plasma protein and platelets. Filtrate is collected in Bowman’s Capsule. permeable, collects filtrate (water, urea, glucose, salt, amino acid, vitamins)

7. Nephrons http://www.youtube.com/watch?v=glu0dzK4dbU http://www.youtube.com/watch?v=glu0dzK4dbU Filtrate passes through the Proximal Convoluted Tube Glucose and K+ is reabsorbed in blood. filtrate passes through Loop Of Henle and looses water and sodium Water passively flows out of the Descending Loop of Henle Salt actively and passively flow out from the Ascending Loop of Henle Distal Convoluted Tube- takes in toxins, drugs and alcohol is absorbed into tube Urine drains into Collecting Duct When filtrate descends down the collection duct, water flows out through osmosis, concentrating the urine.

8. Descending Loop of Henle Ascending Loop of Henle Nephrons

9. Collection Urine drains out of the collecting duct into the Ureter Urine is collected in the urinary bladder Urine is expelled out of the body through the urethra