1. Excretory System
Job:
To filter out and eliminate metabolic, cellular waste
-in the form of nitrogenous wastes
Nitrogenous Waste: cells create ammonia which the liver converts to urea
Urea is the yellow in our urine
-filters outs and gets rid of excess:
water, salts, vitamins, toxins, minerals and heat.

2. Excretory System Humans have 2 kidneys -reddish bean shaped organ
-Size of a clenched fist
-Lie along the small of back

3. Structure of a nephron
Each kidney is made up of one million+ filtering units
Called nephrons
Blood enters kidney via the renal artery
Blood is pushed through a nephron where excess H2O, salt, toxins, minerals, and urea is filtered out.

4. Urine Formation
All nephrons empty into the pelvis/center of the kidney.
The center of the kidney empties into the ureter.
Ureter leads to bladder
Water and impurities that collect in our bladder make up our urine which exits out the urethra

5. The Kidneys A. renal vein B. renal artery C. ureter D. medulla
Nephron
A. renal vein
B. renal artery
C. ureter
D. medulla
Where nephrons are located.
E. renal pelvis
F. cortex

6. Urine Formation Average Adult: ~1.5 Liters/day
Responsible for the greatest
amount of water loss in our
bodies.
Must urinate 500mL/day to get
rid of toxins
-You have 2 kidneys but can live
with one if need be.

7. Nonfunctioning Kidneys
Dialysis:
medical treatment to remove the toxins a healthy kidney would normally remove.