Excretory System

11th Grade Health

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

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

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

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.

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)

Continued…

Kidney stones – 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