I. Homeostasis Overview

2. I. Homeostasis Overview • Regulator - use homeostasis to modify internal change - requires use of energy • Conformer - allows some conditions to change in the body with the environment

3. II. Thermoregulation

4. A. 4 Processes for Heat Gain or Loss • Conduction – direct transfer of heat between molecules in direct contact • Convection – transfer of heat by moving air or liquid over a surface • Radiation – emission of electromagnetic waves by objects warmer then absolute zero • Evaporation – removal of heat from a surface of a liquid that is losing some of its molecules as gas

5. B. 4 Categories of Adaptations • Adjusting Rate of Heat Exchange a. Insulation – feathers, hair, fat b. Vasodilation / Vasoconstriction c. Countercurrent heat exchange • Cooling By Evaporative Heat Loss a. Panting b. Sweating • Behavioral Response a. Moving b. Basking c. Hibernation d. Migration • Change Rate of Metabolic Heat

8. C. How Thermoregulation Occurs in Different Organisms

9. 1. Mammals and Birds • Moving / shivering • Mitochondria make heat instead of ATP / nonshivering thermogenesis • Insulation / raise hair or feathers / fat • Vasodilation / Vasoconstriction • Countercurrent heat exchange • Evaporative cooling / sweat, saliva, urine

10. 2. Amphibians and Reptiles • Mostly behavioral adaptations • “Become” endothermic

11. 3. Fish • Most are conformers b. Countercurrent exchange / cold on surface, warm inside

12. 4. Invertebrates • Most are conformers • Some are endothermic / shiver, countercurrent exchange, huddle

13. D. Thermostat Negative Feedback controlled by the hypothalamus

15. E. Torpor • State with low activity and metabolism • Hibernation – long term torpor / winter • Estivation – summer torpor • Daily Torpor

16. III. Water Balance and Waste Removal Osmoregulation – management of water and solute composition

17. A. Transport Epithelium • Layer that regulates solute movement • Move solutes in specific amounts in a certain direction • Joined by tight junctions

18. B. Nitrogenous Wastes Ammonia – produced when proteins and nucleic acids are broken down / need ATP to make Three Ways to Get Rid of It: Ammonia, Urea, Uric Acid

19. 1. Ammonia • Can only be tolerated in low concentrations • Very toxic • Need to have access to lots of water to use it • Occurs across invertebrates entire body • Lose through gills

20. 2. Urea • Made from CO2 and Ammonia in the liver • Low toxicity • Can be stored and transported in high concentrations • Needs less water / good for terrestrial organisms • Mammals, adult amphibians, marine fish, and turtles use it

21. 3. Uric Acid • Secreted as a semi solid paste • Lose little water • Form as a solid in non-permeable eggs • Insects, birds, and reptiles use it

22. C. Balancing Water Gain and Loss • Osmoconformers – isoosmotic / only marine • Osmoregulators – use energy to control internal osmolarity / discharge water if it lives in a hypotonic environment / takes in water if it lives in a hypertonic environment • Stenohaline – can’t tolerate large changes • Euryhaline – can tolerate large changes

23. Balancing Water Gain and Loss (cont.) • At Sea - dehydration occurs - get water through food - drink sea water and actively transport salt out through gills - very little urine • Fresh Water - contractile vacuoles - excrete lots of dilute urine • Land - body coverings - nocturnal

26. IV. Excretory Systems

28. A. Protonephridia • Flame - bulb systems • Flatworms • Interstitial fluid enters the flame bulb by cilia and filters fluid

30. B. Metanephridia • Annelids / 2 per segment • Brings in coelomic fluid through the nephrostome and exits via nephridiopore • Filters out using capillaries

32. C. Malpighian Tubules • Insects and terrestrial arthropods • Found in hemolymph and enter into the digestive tract • Pull out solutes and water and puts them into the digestive system • Rectum allows for the reabsorption of water and beneficial solutes

34. D. Kidney • Kidney, ureters, bladder, urethra

35. V. Function of the Kidney

36. A. Parts • Renal cortex – outer part • Renal medulla – inner part • Renal artery and vein • Renal pelvis – collection tubes lead here • Nephrons – filter of kidney - cortical – small Loop of Henle - juxtamedullary – large Loop of Henle • Blood vessels

37. A. Parts (cont.) • Bowman’s Capsule – proximal tubule – loop of Henle – distal tubule – collecting duct • Renal artery - afferent arteriole – glomerulus – efferent arteriole – peritubular capillaries – vasa recta – renal vein

39. B. Process 1. Filtrate (urea, bicarbonate, salts, glucose, etc) enters the nephron via the glomerulus into the Bowman’s Capsule and moves into the proximal tubule. It can also enter the proximal tubule via the peritubular capillaries.

41. B. Process 2. In the proximal tubule drugs and poisons stay in the tubule along with the fact that it makes H+ to regulate pH. Bicarbonate, K+, glucose, A.A., Na+, Cl-, and water are all moved back into the interstitial fluid here through active and passive methods. A lot of this will move back into the peritubular capillaries.

43. B. Process 3. The filtrate then moves down the descending limb of the Loop of Henle. Water moves out passively into the interstitial fluid and the osmolarity of the filtrate increases.

45. B. Process 4. Then the filtrate moves up the ascending limb of the Loop of Henle. This is not permeable to water but is to salt. Salt moves out the thin section into the interstitial fluid. The medulla has a very high osmolarity as a result. The thick part of the ascending Loop of Henle actively transports out salt.

47. B. Process 5. The distal tube comes next and, like the proximal tube, it regulates salts, K+, bicarbonate, and H+ (pH).

49. B. Process 6. The collection duct is the last part and it is permeable to water but not salt. So, water leaves into the hypertonic interstitial fluid. At the end salt is actively transported out and some urea moves out as well which makes the medulla even more hyperosmotic.