1. Regulation of the Internal Environment By: Tony Chung, Kani Cheung, Keng Lam, and Rebecca Yang View m.haight's map Taken in (See more photos here ) View m.haight's map Taken in (See more photos here ) View m.haight's map Taken in (See more photos here )

2. Don’t panic! It’s gonna be fun!!!

18. Temperature Regulation of Your Body

21. Hibernation and Estivation

26. Organisms balance the gain and loss of water and regulate solute concentrations

31. The mammalian excretory system (a) Excretory organs and major associated blood vessels

32. The mammalian excretory system (b) Kidney structures

33. The mammalian excretory system (c) Nephron

34. The mammalian excretory system (d) Filtrate and blood flow

36. The nephron and collecting duct: regional functions of the transport epithelium The numbered regions in this diagram are keyed to the circled numbers in the text discussion of kidney function.

39. How the human kidney concentrates urine: the two-solute model. Two solutes contribute to the osmolarity of the interstitial fluid: NaCl and urea. The loop of Henle maintains the interstitial gradient of NaCl, which increase in the descending limb and decrease in the ascending limb. Urea diffuses into the interstitial fluid of the medulla from the collecting duct. The filtrate makes three trips between the cortex and medulla. As the filtrate flows in the collecting duct past interstitial fluid of increasing osmolarity, more water moves out the duct by osmosis, thereby concentrating the solutes, including urea, that are left behind in the filtrate.