1. © 2011 W. H. Freeman and Company CHAPTER 20 Introduction to Animal Physiology What Is Life? A Guide To Biology First Edition What Is Life? A Guide To Biology First Edition Jay Phelan

2. FIGURE 20-3 A negative feedback loop restores the internal environment to a set point.

8. FIGURE 20-4 Regulate or conform? Two strategies to cope with a changing environment.

19. FIGURE 20-5 Patching a tear.

24. FIGURE 20-8 How organisms acquire or dissipate heat.

30. FIGURE 20-13 The nephron is the fundamental unit of the human kidney.

38. FIGURE 20-16 From cells to organ systems.

45. FIGURE 20-17 Tissues perform specific functions in the body.

50. FIGURE 20-19 Connective tissues: the most abundant tissues in most animals.

58. FIGURE 20-22 Muscle tissues are made up of elongated cells capable of generating force when they contract.

62. FIGURE 20-23 Neuron and glial cells.