1. Excretory & Respiratory Systems Lungs and Kidneys

2. Gas Exchange: oxygen & CO 2 Earliest type: Simple diffusion Diffusion = movement of particles to equilibrium!

3. Gas exchange: simple diffusion Protists: amoebas etc Plants: through stomata Examples of organisms that use simple diffusion

4. Gas exchange: skin Some amphibians, worms Skin must be moist to open pores!

5. Gas exchange: insects Tracheal tubes Tubes open to outside of body, allow passive diffusion of gas SPIRACLES are valves that open and close special openings to let in oxygen: SPIRACLES not lungs!!!!

6. Interesting idea: ancient giants What was different about earth’s atmosphere that would let insects grow so big? more oxygen!! Now, oxygen is at 21% Then, it was at 30%!!! http://www.astrobio.net/pressrelease/2431/attack-of-the-giant-insects

7. Gas exchange: Gills Thin layers of tissue letting oxygen diffuse out of water into blood letting CO2 diffuse out of blood into water

8. Gills “counter-current exchange” Fish, (bony & cartilaginous), Mollusks 80% efficiciency rate oxygen carbon dioxide water blood

9. Lungs + Air Sacs: Birds Birds have so many air sacs, they can get fresh oxygen while inhaling OR exhaling!

10. Mammals: nose or blowhole Sinus cavities to filter air Tissue to warm air

11. Trachea: tube for air Cartilage rings around it keeps it from collapsing Choking: blockage of trachea

12. Bronchi: branches into lungs Looks like a branching tree

13. By the way: bronchitis is inflammation (swelling) of the bronchi Usually due to infection or allergies

14. Asthma:

15. Lungs: amphibians, reptiles, mammals Concurrent exchange system

16. Lungs: getting oxygen from air Expanding lungs = contracting diaphragm

17. Take a closer look at lungs: ALVEOLI: small sacks

18. Ocean mammals: Lungs Nose or blowhole

19. Smoker’s Lung:

20. Excretion: water balance! Urinary Tract: filters liquid wastes from body, balances water in blood Removes NITROGEN ous WASTES Also: sweating!

21. Kidney: contains NEPHRONS Units of tubing that remove excess water and liquid wastes from blood

22. General idea of a nephron: In the glomerulus, blood is passed near the tubules to exchange materials

23. Glomerulus Blood can exchange wastes with liquid Excess water will diffuse out of blood into renal tubule

24. Wastes pass through URETER To be stored in bladder Passed out urethra to outside of body Exit controlled by sphincter

25. Sphincters: open and close Muscular “lock”

26. Potty training kids: Wait for nervous system to reach voluntary sphincters 13 months – 36 months

27. Kidney Stones Mineral deposits in kidneys or ureter Painful!

28. UTI: urinary tract infection Bacterial infection Can spread to kidneys if left untreated

29. Control of Water Balance: Brain hormone ADH keeps balance HOMEOSTASIS BEWARE! You can drink too much water You can drink too little water You can kill babies by giving them too much water in their formula!

30. What is dialysis? When kidney’s fail, we have to do their job with machines. USE DIFFUSION!