1. Urinary System 2 metabolic wastes 1.CO 2 2.Urea

2. Urea Contains Nitrogen (N) wastes given off by cells. Nitrogen wastes are toxic Liver collects these wastes (N)  coverts them to urea  released into the blood  kidney will filter out the urea  removed from body in urine

3. Parts of the Urinary System 1. Kidneys: filter out wastes in blood and form urine 2. Ureter: tube that carries urine from kidney to bladder 3. Bladder: collects and stores urine 4. Urethra: carries urine from the body

4. Nitrogen Balance Body must contain a constant level of N 2 Any N 2 lost in the formation of urea must be replaced We obtain N 2 in our diet Foods high in protein- such as: beans, nuts, and meats are a good source

5. *Problem* When proteins (amino acids) are broken down, ammonia is produced NH 3 NH 3 is highly toxic to our bodies The liver detoxifies NH 3 by converting it to urea

6. Breakdown of Red Blood Cells (RBC) RBC’s get old and wear out  Liver must filter them out  which will break down the RBC’s This breakdown causes toxic pigments to be released. These pigments are collected by the liver and added to bile.

7. RBC’s cont…. Bile is absorbed by the small intestines  into the blood  kidneys then filter ou the bile (pigments)  add it to urine *This is what gives urine its nice yellow tint!! REMEMBER…. Don’t eat yellow snow!!

8. Liver Damage When liver isn’t working correctly – pigments are released directly into the blood stream Pigments will collect in the skin cells and in the sclera of the eyes The patient will become jaundice – a yellow tint in the skin and eyes

9. Foreign Toxins Foreign chemicals that enter our bodies are: 1. eliminated and/or excreted as waste 2. broken down, then excreted 3. stored in tissues such as fat

10. How does our body process drugs? Your body reacts to drugs the same way it reacts to anything that enters the body!! It tries to use what it can and breakdown and remove what is left.

11. 2 Kinds of Drugs Water-soluble drugs: Like cocaine are easily and quickly broken down and removed in urine. Fat-soluble drugs: like marijuana must be broken down and converted to a water- soluble substance that is then removed.

12. Biotransformation Process usually occurs in the liver Problem* - some drugs that undergo biotransformation produce substances that can damage the liver and other organs.

13. Drug Tests 1. urine test – use test strips to detect drug use. Cheap and least accurate. 2. Immuno: use of antibodies to detect drug use in blood samples. 3. Gas chromatography/mass spectrometer: very expensive, but very accurate. Separates and identifies chemical make up of a sample.