Liquid Excretion: removal of liquid wastes & water/salt balance

Ch 37.3The Urinary System

Nitrogen wastes are excreted & cycledNitrogen inPlant & animalprotein

Ammonia nitrogenIs excreted in urine

Bacteria convertAmmonia to usableNitrate fertilizer

Forms of Nitrogen Wastes

Nitrogen

form

Toxicity Environment& removal

1. Ammonia Most Water by diffusion

2. Urea Less Land @ kidney as urine

3. Uric Acid

crystal

Least Air & Deserts as

A dry crystal

Protein Building blocks:

Amino

NH2

Acid

COOH

Nitrogen waste from Protein Breakdown

Kidney filters the bloodRemoves urea wasteRecycles food, water & saltUrine = urea waste, water & salt

Bladder stores Urine made by Kidneys

Ureter tubesCarries urine to urethra

Nephron: Unit of filtration

Water levels in urine under control of Hypothalamus & ADH hormone

Kidney Transplants: