1. The Excretory System

2. Functions Excretion - Filtering metabolic wastes Wastes Excess salts
Carbon Dioxide
Urea – produced when amino acids are used for energy

3. Skin
Sweat
Excess water, salt, small amounts of urea

4. Lungs
Excrete CO2 when energy is produced by the mitochondria

5. Liver
Converts amino acids to useful compounds
Produces urea as waste

6. Kidneys Remove waste products from the blood Maintain blood pH
Regulate water content of blood

7. Urinary System

8. The Urinary Organs:
Kidneys: filters that take waste out of the blood and make urine

9. The Urinary Organs:
Ureters: tubes that carry urine to the bladder

10. The Urinary Organs:
Bladder: a muscular bag that collects urine

11. The Urinary Organs:
Urethra: a tube that carries urine out of the body

12. Blood passes through the kidneys in order to deposit used and unwanted water and waste
This forms urine which travels through the ureters to the bladder

13. Kidneys

14. Kidney Regions
Renal Cortex
Renal Medulla
Renal Pelvis

15. Blood Flow Waste-laden blood enters kidneys through the renal artery
Clean filtered blood leaves the kidney through the renal vein

16. Nephron Structural units of the kidney Over 1,000,000 in each kidney!
3 cm long
0.03 mm wide
Filter the blood
Reabsorb water, glucose, and salt
Glomerulus

17. Nephron
Glomerulus
Bowman’s Capsule
Loop of Henle

18. Filtration Blood pressure forces blood through the glomerulus
All blood is filtered every 45 minutes

19. Filtration
Filtrate
Water, urea, glucose, salts, amino acids, and some vitamins
Proteins, cells, and platelets are too large to pass through and remain in the blood

20. Reabsorption Most of the filtrate reenters the blood Active transport
Amino acids, fats, glucose
Osmosis – 99% of water reabsorbed

21. Urine Forms in Kidneys Made up of urea, excess salts, and water
Loop of Henle
Made up of urea, excess salts, and water
Concentration variation
Kidney  Ureter  Bladder
Thirst
your brain is telling you to get more fluids to keep your body as balanced as possible.
If you don't have enough fluids in your body, the brain communicates with the kidneys by sending out a hormone that tells the kidneys to hold onto some fluids.
When you drink more, this hormone level goes down, and the kidneys will let go of more fluids.

22. Bladder Hollow muscular organ Flexible cells
Nerves tell the brain when the bladder is full.
After 200 ml have accumulated
After 1 minute reflex subsides
Holds approximately 500 ml

23. Healthy Diseased Kidney Disease feel more tired and have less energy
have trouble concentrating
have a poor appetite
have trouble sleeping
have muscle cramping at night
have swollen feet and ankles
have puffiness around your eyes, especially in the morning
have dry, itchy skin
need to urinate more often, especially at night.
Healthy
Diseased

24. Dialysis