Excretory SystemPrinceton 7th Grade Science

Main Function• to collect waste products and remove them from

the body

• excrete: to get rid of

Main Parts• Kidneys

• Bladder

• Ureter

• Urethra

• Skin

Kidneys• Remove urea & other waste

products from the body

• Nephrons act as filters within the kidneys

• Kidney stones form as solid particles that may leave the kidneys & pass through the urinary tract—can be extremely painful!

Bladder

• muscular organ that stores urine until it is excreted by the body

Ureter• narrow tube that carries urine from a kidney to the

bladder

• one comes from each kidney to the bladder

Ureter with a tumor

Urethra

• small tube which allows urine to flow out of the body

Stent being placed in urethra Genetically-engineered urethra

Skin

• eliminates waste in the form of perspiration (skin)