Excretory System

A. Excretory System Also known as Urinary system

Functions a. Removes nitrogenous wastes Our bodies have many processes they must perform to function and stay alive

Leaves cells as ammonia and is converted into urea Nitrogenous wastes (Urea), produced by the breakdown of proteins Leaves cells as ammonia and is converted into urea Why must nitrogenous waste be excreted?

Functions b. Maintain homeostasis of body fluids Internal stable conditions

How does it work?

Organs of the excretory system

A. Kidneys Main organs - filter, concentrate, and eliminate wastes from blood

Kidneys a. About the size of a large bar of soap, sit toward the back

Kidneys b. Clean all the blood in the body in about 25 min.

B. Aorta Brings blood from the heart

C. Renal arteries Carry blood into the kidneys

D. Renal veins Carry blood out of the kidneys

E. Inferior vena cava Returns blood to the heart

F. Ureters Tubes that carry urine from the kidneys to the bladder

G. Urinary bladder Muscular bag that stores urine

Bladder Very stretchy!

H. Urethra Tube that releases urine out of the body

3. Other organs A. Lungs – remove CO₂ from the body B. Skin – wastes are released with sweat through pores

Microscopic View of Kidneys

A. Nephron The kidney’s filters, about 1 million per kidney

a. Glomerulus Clump of capillaries, blood pressure forces fluids and wastes out

b. Bowman’s capsule Cup shaped tube that receives the fluids from the glomerulus

5. Urine Leftover fluids after most water and nutrients are reabsorbed Mostly water, urea, uric acid

Urine Color

A. Urine Color Blue Urine Most likely from food dyes or medications Clear Urine Can mean healthy, too hydrated, type of diabetes Dark Yellow Urine Dehydrated, asparagus can turn urine darker color

Urine Color Orange Urine Blackberries, beets, rhubarb or medications, severe dehydration Light Yellow Urine Healthy Green Urine Most likely from food dyes or medications Pink or Red Urine Beets or berries, blood in urine, kidney or bladder infection

6. Healthy Excretory System A. Personal hygiene – keep the area around the urethra clean of bacteria B. Drink plenty of water

7. Problems A. Urinary Tract Infection – overgrowth of bacteria in the urinary tract Frequent, painful urinations

Problems B. Kidney stones – crystallized clumps of materials and salts in the urine

Kidney transplant

Aorta Inferior vena cava Renal arteries kidney Renal veins ureter Urinary bladder urethra