1. http://www.youtube.com/watch?v=hXysuAt_U9s

2. Excretion removal of metabolic waste Protein and nucleic acid metabolism  nitrogen containing compounds does not include feces feces is what your body did not use, therefore not metabolic waste

3. Excretion is an example of homeostasis Prevent build up of toxic wastes within our body Contribute to water balance in our body

4. Organs Responsible for Excretion

5. Composition of Urine solution of metabolic waste Water (mostly) urea and uric acid salts organic compounds

6. Compounds within asparagus are metabolized Produce a byproducts that contain sulfur

7. fluid for urine comes from filtered blood extracellular fluid (ECF)

8. Forms of Nitrogenous Waste Urea Ammonia Uric Acid

9. deamination – removal of amine group Occurs in the liver Byproducts are sent to the kidneys for further processing

10. Urea product of two other waste molecules ammonia, NH 3 (very toxic) carbon dioxide, CO 2 Where does the ammonia come from? amine group from amino acids

11. Ammonia ammonia released when liver breaks down proteins 0.005 mg NH 3 is lethal reacts with CO 2 to produce less toxic urea 100 000x less toxic than NH 3

12. Uric Acid product of nucleic acid breakdown specifically of purine bases

13. Role of Kidneys 1. Removal of wastes Urea, uric acid and other materials are filtered through the kidney and excreted 2. Water balance average person loses 2L of liquids a day suggested to consume 2L H 2 O / day

14. Excretion: Ameoba Ameoba remove waste and excess water through a contractile vacuole.

15. Excretion: Fish Fish can excrete ammonia directly through their gills.

16. Excretion: Birds Birds excrete uric acid directly with feces.

17. Excretion: Earthworms capillary network bladder collection tubule nephridiopore nephrostome

18. AKA The Kidney

19. Role of Kidney 1. blood filtration 2. waste excretion 3. acid / base balance 4. blood pressure regulation 5. hormone secretion

20. Kidney Structure renal cortex – outside of kidney; location of Bowman’s capsule renal medulla (lobes) – middle of kidney; location of loop of Henle renal pelvis – location of the ends of collecting ducts

21. Kidney Blood Flow Blood enters the kidney through the renal artery. renal arteries stem from the aorta Carry oxygenated blood Filtered blood exits the kidney through the renal vein. renal veins flow into the inferior vena cava Carry de-oxygenated blood

23. Nephron Functional unit of the kidney Responsible for the formation of urine A million nephrons make up the kidney

24. Blood and the Nephron Blood from renal artery is filtered through nephrons. Nephrons collect liquid to be excreted Filtered blood is returned to renal vein

25. The renal artery is split into afferent arterioles. blood brought to glomerulus; a capillary bed. blood leaves through the efferent arterioles no veins involved Efferent arterioles are the beginning of a network of peritubular capillaries, that wrap around the nephron. Renal artery

26. Glomerulus and Bowman’s Capsule Filtrate A fferent Arteriole E fferent Arteriole

27. From the bowman’s capsule: fluids to become urine flow to narrow proximal tubule urine flows through loop of Henle urine flows through distal tubule Urine from multiple nephrons flow into the collecting duct.

28. Urine Flow Urine leaves the renal pelvis through the ureters and travels to the bladder. Fluid leaves the body through the urethra. When ~200 mL of urine has collected in the bladder, the walls stretch and signals are sent to the brain. At ~600 mL, urine will involuntarily be released. ureters

29. http://www.sumanasinc.com/webcontent/animations /content/kidney.html http://www.sumanasinc.com/webcontent/animations /content/kidney.html

30. Nephron Structure afferent arteriole efferent arteriole glomerulus Bowman’s capsule proximal tubule Loop of Henle distal tubule collucting duct

31. Urinary System aorta inferior vena cava renal artery renal vein kidney ureter bladder urethra renal cortex renal medulla renal pelvis nephrons ureter

32. Question Athletes now undergo random urine testing for drugs. Describe the pathway of drugs through the urinary system, from the time they enter the glomerulus until they are excreted in the urine.

33. Classwork/Homework 7.3 – Pg. 345 #1-4,6 7.4 – Pg. 348 #1-3 Homework Quiz next class!