1. Excretory System
11th Grade Health

2. The body system that filters waste from the blood and eliminates in the form of urine.
General Purpose
filter excess salt, water and nitrogenous waste from the blood
store waste
elimination waste

3. Structure & Function
Kidneys – two bean shaped organs (size of a fist) located in the small of your back; ~50 gallons of blood is filtered through every day
Nephrons – functional part of kidneys; place where filtration occurs
Ureters – tubes leading from the kidneys to the bladder

4. Continued…
Bladder – muscular organ that stores waste in the form of urine; holds up to a pint of urine
Urethra – tube leading from the bladder to the outside of the body
Urine – liquid waste material

6. Other Organs of the Excretory System
Lungs – expel carbon dioxide from the body
Skin – release waste through the sweat glands in the form of sweat
Colon – release solid waste from the digestive tract
Liver – over 500 functions, one includes metabolizing toxins in the body, so they can be eliminated.

7. Problems of the Excretory System
Incontinence – inability to control the functioning of the bladder; more common in older adults
Nephritis – inflammation of the nephrons causing high blood pressure, fatigue and swelling of body tissue (blood in urine)

8. Continued… Kidney stones Kidney failure
stone-like crystals that sometimes form from mineral salts;
small ones pass out with urine; large ones must be broken down (sound waves).
Signs include extreme pain/discomfort, inability to urinate adequately/completely, blood in urine and pain during urination.
Kidney failure
kidneys stop working; person can live with one kidney, but will die if both do not work
Dialysis
procedure where a person is hooked up to an artificial kidney machine which filters waste from the blood
performed at least 3 times every week for about 4 hours each time