Excretory System learning the ways of waste Learning

Excretory System learning the ways of waste… Learning Target: I can explain the role of the excretory system in animals and identify the organs involved in human anatomy.

What Do Animal Cells Do To Stay Alive? § Animal cells move material across the cell membrane by diffusion u nutrients and fuels for energy § from digestive system u nutrients oxygen in O 2 sugar § from respiratory system O 2 u waste out sugar CO 2 urea nutrients § CO 2 leaves by respiratory system § urea from cells, leaves by excretory system

Learning Target: I can explain the role of the excretory system in animals and identify the organs involved in human anatomy. Unicellular Multicellular Unicellular Multicellular • All cells in direct contact with environment • All cells can easily get nutrients in & waste out by diffusion • Internal cells not in direct contact with environment • Internal cells can’t get nutrients in & waste out • Need organ systems

Keeping An Animal Alive § Had to evolve organ systems for: getting materials in & around § digestive system § respiratory system § circulatory system u removing wastes § respiratory system § excretory system u

What Liquid Waste Do We Make? § Digesting protein makes poison u nitrogen waste = ammonia = poison H O | || H N —C— C—OH | H H NH 2 = ammonia CO 2 + H 2 O

Nitrogen Waste § The kind of waste you make depends on where you live u u u Freshwater § ammonia Land § urea Land egg layer § uric acid

Nitrogen Waste Disposal In Water § Freshwater animals u If you have a lot of water you can dilute the waste before it poisons you § excrete ammonia through gills and as urine Learning Target: I can explain the role of the excretory system in animals and identify the organs involved in human anatomy.

Nitrogen Waste Disposal On Land § Land animals need to save H 2 O u evolved less poisonous waste product u § urea u excrete urea & H 2 O as urine Learning Target: I can explain the role of the excretory system in animals and identify the organs involved in human anatomy.

Urea and Skin…. § Did You Know: Urea in its pure form is a powder u This powder is very good for your skin u § Its even found in most make-up! Learning Target: I can explain the role of the excretory system in animals and identify the organs involved in human anatomy.

Human Kidney § Mammals have a pair of bean-shaped kidneys u supplied with blood by a renal artery and a renal vein Learning Target: I can explain the role of the excretory system in animals and identify the organs involved in human anatomy.

Bowman’s capsule Proximal tubule Distal tubule Glomerulus Glucose Amino acids Mg++ Ca++ H 2 O Na+ Cl. H 2 O Loop of Henle kidney’s filtering unit Collecting duct

Kidneys: -contains millions of nephrons -nephrons filter the blood -removes wastes by diffusion Ureters: -brings waste to bladder Urinary Bladder: Urethra: -brings waste from bladder to outside world -holds waste from kidneys -make of special tissue that allows for expansion

Nitrogen Waste Disposal in Egg § Egg-laying land animals no place to get rid of waste while in egg u needs waste that doesn’t dissolve in water inside egg u § uric acid § stays a powder inside egg u birds, reptiles, insects

Uric Acid Getting a little personal, aren’t we! § Bird & reptile waste large molecule that doesn’t dissolve in water inside egg u stays as a white powder u § doesn’t harm embryo in egg § adults excrete white paste not liquid waste w white bird poop is really their pee! w this is why male birds don’t have a penis! Learning Target: I can explain the role of the excretory system in animals and identify the organs involved in human anatomy.

So Why Do Humans Dave Two Kinds of Waste? nutrients CO 2 urea Learning Target: I can explain the role of the excretory system in animals and identify the organs involved in human anatomy.