Excretory System Fluid’s

October 13, 2011 You need: Clean paper /pencil Warm Up: Turn in your book to Chapter 11-3. What is the excretory system?

October 13, 2011 In your book – Chapter 11, section 3 Write out the 3 key concept questions. Define the 8 key terms

Main Function: Collects waste produced by cells and removes the wastes from the body. (also known as: excretion)

Wastes Eliminated: Excess water Urea – chemicals that come from the break down of proteins Other wastes

The path of the excretory system Kidneys – filter blood Ureters – narrow tubes that leading from the kidneys to the bladder Urinary Bladder-fist sized pouch (muscular sac) that holds about 2 cups of urine Urethra – exit tube

The Kidneys and their Nephrons Kidneys filter the blood Nephrons are used to filter wastes from the blood in your kidneys 1. wastes and needed materials, like glucose and water, are taken out of blood 2. needed materials are returned to the blood, wastes are eliminated.

Nephrons After the reabsorption process is complete, the liquid that remains in the tube is called… URINE. Capillaries Capillaries Urea Urea, water, glucose, and other materials… water, glucose Kidney

After the reabsorbing process is complete, the liquid that remains in the tube is called… URINE.

What happens in the Nephrons? Materials and wastes go through the tubes Protein, glucose, most water, and some other materials return to the blood Wastes and small amounts of water stay and are excreted

Pee in a cup? Urine used to determine diseases Glucose in urine = diabetes Protein = kidneys not functioning correctly

Homeostasis with Excretion Excretion maintains homeostasis by keeping the body’s internal environment stable and free of harmful levels of chemicals. Kidneys Lungs and Skin Liver

Homeostasis Kidneys Regulate amount of water in your body Hot day – you will sweat a lot, but you don’t drink a lot so you excrete small amounts of urine

Homeostasis Lungs and Skin Exhale carbon dioxide and water vapor Sweat water and urea Liver Breaks down wastes before excreting them