THE EXCRETORY SYSTEM WHAT IS EXCRETION Excretion The

THE EXCRETORY SYSTEM

WHAT IS EXCRETION? Excretion: The removal of wastes produced by cells. Major Cellular Wastes: § Carbon Dioxide § Water § Mineral Salts § Nitrogenous Compounds § Compounds such as Urea and Uric Acid that are produced from the breakdown of protein.

PARTS OF THE EXCRETORY SYSTEM Lungs Liver Skin (Sweat Glands) Urinary System Why do we need excretion? §If cellular wastes accumulate in the body, you may become sick or die.

EXCRETION IN THE LUNGS Lungs exhale carbon dioxide, which is a waste product of cellular respiration.

EXCRETION IN THE LIVER Large multipurpose organ. Produces Urea (nitrogenous compound) from excess Amino Acids Purifies blood by removing drugs and alcohol.

EXCRETION IN THE SKIN Sweat Glands excrete perspiration Perspiration composed of: §Urea §Salt §Water

THE URINARY SYSTEM Excretion in the Kidneys

Diagram of the Urinary System

EXCRETION BY THE URINARY SYSTEM Kidneys: filter the blood and produce urine through subunits called nephrons. Ureters: transport urine from the Kidneys to the Bladder. Urinary Bladder: temporarily stores urine. Urethra: single tube that excretes the urine from the body.

THE KIDNEYS Useful substances are removed from the kidney and returned to the blood. § Glucose § Amino Acids § Some salts § 99% of Water Urine proceeds through the urinary system and is eventually excreted. § Urea § Some Water § Some Salts