Excretory System

Function

• Removal of waste from blood and lymph to maintain homeostasis– Wastes removed

• Excess salts

• Carbon dioxide (CO2)

• Urea

• Regulates pH of blood, water content of body, and volume of blood

Organs Involved

• Kidneys– Most important!

• Ureters– Connect kidney to bladder

• Bladder– Stores wastes for urination– Prostate gland (only in males)

• Urethra– Urine exits the body

Kidneys• Located on each side near the

lower back

• Filtration– Urea, water, glucose, salts, vitamins

and other wastes are filtered out of the blood by nephrons in the kidney

• Reabsorption– Purified blood is recycled by the body

• Wastes become urine and are transported out of the kidney to…

Ureters

• Transport urine from kidneys to bladder

Bladder and Urethra• Stores urine until enough is collected to be

released through the urethra out of the body

Kidney Stones

• Crystallized pieces of calcium, magnesium, or uric acid salts can block the ureter– VERY painful!

• Must be passed through the urine to exit the body– Can be broken apart by

soundwave treatment to make this process less painful

• One cause = drinking too much soda