Set your sights on success in biology with this interactive personal assessment tool www.cengagenow.com/tlc CengageNOW™ is web-based, powerful, and interactive! This dynamic resource will help you gauge your own unique study needs. Then, the program generates a Personalized Study plan that will help you focus your study time on the biology concepts you most need to master. You will quickly begin to optimize your study time and get one step closer to success. PLUS: Through CengageNOW, you can access narrated animations of hundreds of the illustrations in this book. An Animated! notation next to a fi gure number directs you to the animated or interactive version. CengageNOW™ will help you: ▶ Create a Personalized Study plan for each chapter of this text ▶ Understand key concepts in the course ▶ Prepare for exams and increase your chances of success ▶ Easily access specifi c book pages through eBook sections ▶ Study using video, animations, and interactive tutorials How can you gain access to CengageNOW? If the access code card was not ordered with your text, you can purchase access to this remarkable program at www.ichapters.com, where easy-to- follow instructions will help you purchase an electronic access code. HUMAN BIOLOGY EIGHTH EDITION This page intentionally left blank HUMAN BIOLOGY EIGHTH EDITION CECIE STARR Belmont, California BEVERLY McMILLAN Gloucester, Virginia Australia Brazil Japan Korea Mexico Singapore Spain United Kingdom United States Human Biology, Eighth Edition © 2010, 2007 Brooks/Cole, Cengage Learning Cecie Starr and Beverly McMillan ALL RIGHTS RESERVED. 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Printed in Canada 1 2 3 4 5 6 7 12 11 10 09 08 BRIEF CONTENTS 1 Learning about Human Biology 2 Chemistry of Life 3 Cells and How They Work 4 Tissues, Organs, and Organ Systems 5 The Skeletal System 6 The Muscular System 7 Circulation: The Heart and Blood Vessels 8 Blood 9 Immunity and Disease 10 The Respiratory System 11 Digestion and Nutrition 12 The Urinary System 13 The Nervous System 14 Sensory Systems 15 The Endocrine System 16 Reproductive Systems 17 Development and Aging 18 Cell Reproduction 19 Introduction to Genetics 20 Chromosomes and Human Genetics 21 DNA, Genes, and Biotechnology 22 Genes and Disease: Cancer 23 Principles of Evolution 24 Principles of Ecology 25 Human Impacts on the Biosphere BRIEF CONTENTS v DETAILED CONTENTS 1 Learning about Human Atoms are composed of smaller particles 16 Biology 1 Isotopes are varying forms of atoms 16 Radioisotopes may help diagnose disease IMPACTS, ISSUES and save lives 17 What Kind of World Do We Live In? 1 2.2 Science Comes to Life How Much Are 1.1 The Characteristics of Life 2 You Worth? 17 1.2 Our Place in the Natural World 3 2.3 Chemical Bonds: How Atoms Humans have evolved over time 3 Interact 18 Humans are related to all other living things— Atoms interact through their electrons 18 and they have some distinctive Chemical bonds join atoms 18 characteristics 3 Atoms can combine into molecules 19 1.3 Life’s Organization 4 2.4 Important Bonds in Biological Nature is organized on many levels 4 Molecules 20 Organisms are connected through the flow An ionic bond joins atoms that have opposite of energy and cycling of materials 4 electrical charges 20 1.4 Using Science to Learn about In a covalent bond, atoms share the Natural World 6 electrons 20 Science is a systematic study of nature 6 A hydrogen bond is a weak bond between Many scientists use experiments polar molecules 21 in their work 7 2.5 Water: Indispensable for Life 22 Science never stops 7 Hydrogen bonding makes water liquid 22 1.5 Critical Thinking in Science and Life 8 Water can absorb and hold heat 22 Evaluate the source of information 8 Water is a biological solvent 23 Evaluate the content of information 8 2.6 Focus on Health How Antioxidants 1.6 Science in Perspective 9 Protect Cells 23 It is important to understand what the word 2.7 Acids, Bases, and Buffers: “theory” means in science 9 Body Fluids in Flux 24 Science has limits 9 The pH scale indicates the concentration 1.7 Focus on Health Living in a World of of hydrogen ions in fluids 24 Infectious Disease 10 Acids give up H(cid:2)and bases accept H(cid:2) 24 Infections are a threat because they disrupt A salt releases other kinds of ions 25 homeostasis 10 Buffers protect against shifts in pH 25 What do pathogens look like? 10 2.8 Molecules of Life 26 Emerging diseases present new Biological molecules contain carbon 26 challenges 10 Carbon’s key feature is versatile Antibiotics are a double-edged sword 11 bonding 26 Functional groups affect the chemical 2 Chemistry of Life 15 behavior of organic compounds 26 Cells have chemical tools to assemble and IMPACTS, ISSUES break apart biological molecules 27 Fearsome Fats 15 2.9 Carbohydrates: Plentiful and Varied 28 2.1 Atoms and Elements 16 Simple sugars are the simplest Elements are fundamental forms carbohydrates 28 of matter 16 vi CONTENTS Oligosaccharides are short chains 3.6 The Nucleus 48 of sugar units 28 A nuclear envelope encloses the Polysaccharides are sugar chains nucleus 48 that store energy 29 The nucleolus is where cells make 2.10 Lipids: Fats and Their Chemical Kin 30 the parts of ribosomes 49 Fats are energy-storing lipids 30 DNA is organized in chromosomes 49 Phospholipids are key building blocks Events that begin in the nucleus continue of cell membranes 31 to unfold in the cell cytoplasm 49 Cholesterol and steroids are built 3.7 The Endomembrane System 50 from sterols 31 ER is a protein and lipid assembly line 50 2.11 Proteins: Biological Molecules Golgi bodies “finish, pack, and ship” 50 with Many Roles 32 A variety of vesicles move substances Proteins are built from amino acids 32 into and through cells 51 The sequence of amino acids is a 3.8 Mitochondria: The Cell’s Energy protein’s primary structure 32 Factories 52 2.12 A Protein’s Shape and Function 34 Mitochondria make ATP 52 Proteins fold into complex shapes that ATP forms in an inner compartment determine their function 34 of the mitochondrion 52 A protein may have more than one 3.9 The Cell’s Skeleton 53 polypeptide chain 34 3.10 How Diffusion and Osmosis Move Glycoproteins have sugars attached and Substances across Membranes 54 lipoproteins have lipids 35 In diffusion, a dissolved molecule or ion moves Disrupting a protein’s shape denatures it 35 down a concentration gradient 54 2.13 Nucleotides and Nucleic Acids 36 Each type of solute follows its own Nucleotides are energy carriers and gradient 54 have other roles 36 Water crosses membranes by osmosis 54 Nucleic acids include DNA and the RNAs 36 3.11 Other Ways Substances Cross 2.14 Focus on Our Environment Cell Membranes 56 Food Production and a Chemical Many solutes cross membranes through the Arms Race 37 inside of transport proteins 56 Vesicles transport large solutes 56 3 Cells and How They 3.12 Focus on Health When Mitochondria Fail 57 Work 41 3.13 Metabolism: Doing Cellular Work 58 IMPACTS, ISSUES ATP is the cell’s energy currency 58 Alcohol and Liver Cells 41 There are two main types of metabolic 3.1 What Is a Cell? 42 pathways 58 All cells are alike in three ways 42 Enzymes play a vital role in metabolism 59 There are two basic kinds of cells 42 To maintain homeostasis, the body controls Most cells have a large surface area the activity of enzymes 59 compared to their volume 42 3.14 How Cells Make ATP 60 Membranes enclose cells and organelles 43 Cellular respiration makes ATP 60 3.2 The Parts of a Eukaryotic Cell 44 Step 1: Glycolysis breaks glucose down to pyruvate 60 3.3 ScienceComes to Life How Do We See Step 2: The Krebs cycle produces energy-rich Cells? 45 transport molecules 60 3.4 The Plasma Membrane: A Double Step 3: Electron transport produces Layer of Lipids 46 many ATP molecules 61 The plasma membrane is a mix of lipids 3.15 Summary of Cellular Respiration 62 and proteins 46 3.16 Alternative Energy Sources Proteins carry out most of the functions in the Body 63 of cell membranes 46 The plasma membrane is “selective” 47 Glucose from carbohydrates is the body’s main energy source 63 3.5 Focus on Our Environment Deadly Fats and proteins also provide energy 63 Water Pollution 47 CONTENTS vii 4 Tissues, Organs, There are two kinds of bone tissue 88 A bone develops on a cartilage model 88 and Organ Systems 67 Bone tissue is constantly “remodeled” 89 5.2 The Skeleton: The Body’s Bony IMPACTS, ISSUES A Stem Cell Future? 67 Framework 90 Bones, ligaments, and tendons are the basic 4.1 Epithelium: The Body’s Covering components of the skeleton 90 and Linings 68 Bones have several important functions 90 There are two basic types of epithelia 68 Glands develop from epithelium 68 5.3 The Axial Skeleton 92 The skull protects the brain 92 4.2 Connective Tissue: Binding, Support, Facial bones support and shape and Other Roles 70 the face 92 Fibrous connective tissues are strong The vertebral column is the backbone 93 and stretchy 70 The ribs and sternum support and help Cartilage, bone, adipose tissue, and blood protect internal organs 93 are specialized connective tissues 70 5.4 The Appendicular Skeleton 94 4.3 Muscle Tissue: Movement 72 The pectoral girdle and upper limbs 4.4 Nervous Tissue: Communication 73 provide flexibility 94 Neurons carry messages 73 The pelvic girdle and lower limbs Neuroglia are support cells 73 support body weight 95 4.5 Focus on Health Replacing Tissues 73 5.5 Joints: Connections between Bones 96 4.6 Cell Junctions: Holding Tissues 5.6 Disorders of the Skeleton 98 Together 74 Inflammation is a factor in some 4.7 Tissue Membranes: Thin, Sheetlike skeletal disorders 98 Covers 75 Joints are susceptible to strains, Epithelial membranes pair with sprains, and dislocations 98 connective tissue 75 Bones break in various ways 98 Membranes in joints consist of Genetic diseases, infections, and cancer connective tissue 75 all may affect the skeleton 99 4.8 Organs and Organ Systems 76 5.7 Connections The Skeletal System in 4.9 The Skin: An Example of an Homeostasis 100 Organ System 78 Epidermis and dermis are the skin’s two 6 The Muscular System 103 layers 78 Sweat glands and other structures develop IMPACTS, ISSUES from epidermis 79 Pumping Up Muscles 103 Skin disorders are common 79 6.1 The Body’s Three Kinds of Muscle 104 4.10 Homeostasis: The Body in Balance 80 The three kinds of muscle have different The internal environment is a pool structures and functions 104 of extracellular fluid 80 6.2 The Structure and Function Homeostasis requires the interaction of of Skeletal Muscles 106 sensors, integrators, and effectors 80 A whole skeletal muscle consists Negative feedback is the most common of bundled muscle cells 106 control mechanism in homeostasis 80 Bones and skeletal muscles work 4.11 How Homeostatic Feedback Maintains like a system of levers 106 the Body’s Core Temperature 82 Many muscles are arranged Excess heat must be dissipated 82 as pairs or in groups 106 Several responses counteract cold 83 Skeletal muscle includes “fast” and “slow” types 107 5 The Skeletal System 87 6.3 How Muscles Contract 108 A muscle contracts when its cells IMPACTS, ISSUES shorten 108 Creaky Joints 87 Muscle cells shorten when actin filaments 5.1 Bone: Mineralized Connective slide over myosin 109 Tissue 88 viii CONTENTS