PART 6   Health and Physiology

20  •  Introduction to Animal Physiology 791

Principles of animal organization and function

Animal body structures reflect their functions. 792

20.1

Most animal bodies are organized in a hierarchy from cells to tissues, organs, and organ systems. 792

20.2

Connective tissue provides support. 795

20.3

Epithelial tissue covers most interior and exterior surfaces of the body. 797

20.4

Muscle tissue enables movement. 798

20.5

Nervous tissue transmits information. 800

20.6

Each organ system performs special tasks. 801

Animals have an internal environment. 804

20.7

Our bodies function best within a narrow range of internal conditions. 804

20.8

Animals regulate their internal environment through homeostasis. 805

How does homeostasis work? 807

20.9

Negative and positive feedback systems influence homeostasis. 807

20.10

Temperature control is a component of homeostasis. 809

20.11

This is how we do it: Why do we yawn? 813

20.12

Animals must balance their water content within a narrow range. 815

20.13

In humans, the kidneys regulate water balance. 817

StreetBIO: KNOWLEDGE YOU CAN USE

Your body sometimes deliberately upsets homeostasis. (And you might not want to fight it) 820