HUMAN BIOLOGY

xvi 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


• In some disorders, brain neurons break down


• brain tissue Infections and cancer inflame or destroy


• Headaches only seem like brain “disorders”


• and mood Various neural disorders affect development, behavior,


• 13.12 Science Comes to Life: Studying the Brain


• Altering” Drugs 13.13 Focus on Health: The Brain on “Mind-


• in Homeostasis 13.14 Connections: The Nervous System


• 14 Sensory Systems


• 14.1 Sensory Receptors and Pathways


• 14.2 Somatic Sensations


• and more Receptors near the body surface sense touch, pressure,


• as pain and itching Free nerve endings detect stimuli that we perceive


• Referred pain is a matter of perception


• 14.3 Taste and Smell: Chemical Senses


• Gustation is the sense of taste


• Olfaction is the sense of smell


• 14.4 Science Comes to Life: Tasty Science


• 14.5 Hearing: Detecting Sound Waves


• The ear gathers “sound signals”


• Sensory hair cells are the key to hearing


• Position 14.6 Balance: Sensing the Body’s Natural


• 14.7 Disorders of the Ear


• 14.8 Vision: An Overview


• The eye is built to detect light


• Eye muscle movements fine-tune the focus


• 14.9 From Visual Signals to “Sight”


• Rods and cones are the photoreceptors


• Visual pigments intercept light energy


• The retina begins processing visual signals


• Signals move on to the visual cortex


• 14.10 Disorders of the Eye


• Some eye disorders are inherited


• and cancer The eyes also are vulnerable to infections


• of eye disorders Aging increases the risk of some types


• problems and treat eye injuries Medical technologies can remedy some vision


• 15 The Endocrine System


• 15.1 The Endocrine System: Hormones


• carried in the bloodstream Hormones are long-distance signaling molecules


• and often interact Hormones are produced in small amounts


• 15.2 Types of Hormones and Their Signals


• Hormones come in several chemical forms


• Steroid hormones interact with cell DNA


• of second messengers Nonsteroid hormones act indirectly, by way


• 15.3 The Hypothalamus and Pituitary Gland


• hormones made in the hypothalamus The posterior pituitary lobe stores and releases


• The anterior pituitary lobe makes hormones


• 15.4 Hormones as Long-Term Controllers


• 15.5 GH Growth Functions and Disorders


• 15.6 The Thyroid and Parathyroid Glands


• Thyroid hormones affect metabolism and growth


• calcium regulator PTH from the parathyroids is the main


• 15.7 Adrenal Glands and Stress Responses


• and mineralocorticoids The adrenal cortex produces glucocorticoids


• blood circulation Hormones from the adrenal medulla help regulate


• Endocrine Disrupters 15.8 Focus on Our Environment: Phthalates:


• 15.9 The Pancreas: Regulating Blood Sugar


• 15.10 Blood Sugar Disorders


• Type 2 diabetes is a global health crisis


• “Prediabetes” is a warning sign


• Low blood sugar threatens the brain


• 15.11 Other Hormone Sources


• The gonads produce sex hormones


• The pineal gland makes melatonin


• also produce hormones Skeletal muscle, the thymus, the heart, and the GI tract


• in Homeostasis 15.12 Connections: The Endocrine System


• 16 Reproductive Systems


• 16.1 The Female Reproductive System


• Ovaries are a female’s primary reproductive organs


• an ovary During the menstrual cycle, an oocyte is released from


• 16.2 The Ovarian Cycle: Oocytes Develop


• Hormones guide ovulation


• The ovarian and menstrual cycles dovetail


• 16.3 The Male Reproductive System


• Sperm form in testes


• epididymis Sperm mature and are stored in the coiled


• gland help form semen Substances from seminal vesicles and the prostate


• 16.4 How Sperm Form CONTENTS xiii


• Sperm form in seminiferous tubules


• Hormones control the formation of sperm


• and Females 16.5 Sexual Intercourse between Males


• physiological changes In sexual intercourse, both partners experience


• Intercourse can produce a fertilized egg


• 16.6 Fertilization


• 16.7 Preventing Pregnancy


• options Surgery and barrier methods are the most effective


• Abortion is highly controversial


• 16.8 Options for Coping with Infertility


• Fertility drugs stimulate ovulation


• insemination and IVF Assisted reproductive technologies include artificial


• Diseases 16.9 Some Common Sexually Transmitted


• in young sexually active people Chlamydia infections and PID are most common


• Gonorrhea may have no symptoms at first


• Syphilis eventually affects many organs


• 16.10 STDs Caused by Viruses and Parasites


• Genital herpes is a lifelong infection


• Human papillomavirus can lead to cancer


• Hepatitis can be sexually transmitted


• Parasites cause some STDs


• Sex 16.11 Focus on Health: Eight Steps to Safer


• System 16.12 Cancers of the Breast and Reproductive


• Breast cancer is a major cause of death


• Uterine and ovarian cancer affect women


• Testicular and prostate cancer affect men


• 16.13 Focus on Human Impact: Eggs for ART


• 17 Development and Aging


• 17.1 Overview of Early Human Development


• of cells After fertilization, the zygote soon becomes a ball


• Three primary tissues are the first to form


• Next, cells become specialized


• A process called morphogenesis forms organs


• 17.2 From Zygote to Implantation


• Cleavage produces a multicellular embryo


• Implantation secures the embryo in the uterus


• 17.3 Focus on Health: A Baby Times Two


• 17.4 How the Early Embryo Develops


• First, a basic body plan is established


• and proportions Next, organs develop and take on the proper shape


• 17.5 The Four Extraembryonic Membranes


• Nutrients, and Other Substances 17.6 The Placenta: A Pipeline for Oxygen,


• Appear 17.7 The Second Four Weeks: Human Features


• 17.8 Development of the Fetus


• In the second trimester, movements begin


• Organ systems mature during the third trimester


• features The blood and circulatory system of a fetus have special


• 17.9 Birth and Beyond


• for childbirth Maternal changes and fetal hormones set the stage


• Labor has three stages


• glands Lactation is milk production in a mother’s mammary


• and Birth Defects 17.10 Disorders: Miscarriages, Stillbirths,


• Poor maternal nutrition puts a fetus at risk


• Infections present serious risks


• Drugs of all types may do harm


• Detecting Birth Defects 17.11 Science Comes to Life: Prenatal Diagnosis:


• 17.12 From Birth to Adulthood


• There are many transitions from birth to adulthood


• Adulthood is also a time of bodily change


• 17.13 Time’s Toll: Everybody Ages


• Genes may determine the maximum life span


• in aging Cumulative damage to DNA may also play a role


• the skeleton Visible changes occur in skin, muscles, and


• Most other organ systems also decline


• Aging also alters the brain and senses


• 18 Cell Reproduction


• 18.1 Reproduction: Continuing the Life Cycle


• Body cells have two sets of 23 chromosomes


• Gametes have only one set of chromosomes


• Cell Division 18.2 Overview of the Cell Cycle and


• for cell division A chromosome undergoes changes in preparation


• 18.3 The Four Stages of Mitosis


• Mitosis begins with prophase


• Next comes metaphase


• Anaphase, then telophase follow


• 18.4 How the Cytoplasm Divides


• Controversies over Irradiation 18.5 Science Comes to Life: Concerns and


• Irradiation has varying effects on the body


• Food may be irradiated to kill pathogens


• Concerns 21.10 Applying Biotechnology to Human


• Researchers are exploring gene therapy


• Genes can be inserted two ways


• Gene therapy results have been mixed


• fingerprints Genetic analysis also is used to read DNA


• and Plants 21.11 Engineering Bacteria, Animals,


• Clone? 21.12 Science Comes to Life: To Clone or Not to


• raises concerns Cloning of bacteria, plants, and nonhuman animals


• Controversy swirls over cloning


• Cancer 22 Genes and Disease:


• 22.1 The Characteristics of Cancer


• Some tumors are cancer, others are not


• A cancer cell’s structure is abnormal


• Cancer cells also do not divide normally


• 22.2 Cancer, a Genetic Disease


• Cancer usually involves several genes


• to cancer Various factors can cause mutations leading


• from Environmental Chemicals 22.3 Focus on Our Environment: Cancer Risk


• 22.4 Major Types of Cancer


• 22.5 Cancer Screening and Diagnosis


• of cancer Blood tests can detect chemical indications


• of tumors Medical imaging can reveal the site and size


• Biopsy is the surest way to diagnose cancer


• 22.6 Cancer Treatment and Prevention


• Chemotherapy and radiation kill cancer cells


• Good lifestyle choices can limit cancer risk


• 23 Principles of Evolution


• 23.1 A Little Evolutionary History


• Individuals Vary 23.2 A Key Evolutionary Idea:


• Individuals don’t evolve—populations do


• Genetic differences produce variation


• Arise 23.3 Microevolution: How New Species


• Mutation produces new forms of genes


• of a population Natural selection can reshape the genetic makeup


• Chance can also change a gene pool


• The ability to interbreed defines a species


• 23.4 Looking at Fossils and Biogeography


• Fossils are found in sedimentary rock


• The fossil record is spotty


• evolutionary events Biogeography provides other clues about ancient


• of Body Parts 23.5 Comparing the Form and Development


• evolutionary connections Comparing body forms is one way to uncover


• Development patterns also provide clues


• 23.6 Science Comes to Life: Comparing Genes


• 23.7 How Species Come and Go


• In extinction, species are lost forever


• In adaptive radiation, new species arise


• 23.8 Evolution from a Human Perspective


• Five trends mark human evolution


• 23.9 Emergence of Early Humans


• Early hominins lived in central Africa


• We all come from Africa


• 23.10 Earth’s History and the Origin of Life


• Conditions on early Earth were intense


• to evolve Biological molecules paved the way for cells


• 24 Principles of Ecology


• 24.1 Some Basic Principles of Ecology


• 24.2 Feeding Levels and Food Webs


• feeding levels Energy moves through a series of ecosystem


• Food chains and webs show who eats whom


• 24.3 Energy Flow through Ecosystems


• Producers capture and store energy


• Consumers take energy from ecosystems


• 24.4 Introduction to Biogeochemical Cycles


• 24.5 The Carbon Cycle


• 24.6 The Nitrogen Cycle


• the Biosphere 25 Human Impacts on


• 25.1 Human Population Growth


• The human population has grown rapidly


• growth in different countries and regions Demographics help explain differences in population


• 25.2 Nature’s Controls on Population Growth


• support There is a limit on how many people Earth can


• of Biodiversity 25.9 Endangered Species and the Loss


• Habitat loss pushes species to the brink


• Marine resources are being overharvested


• The principle of sustainability is the answer


• Magnification 25.10 Science Comes to Life: Biological


• Appendix I: Concepts in Cell Metabolism A-


• Appendix II: Periodic Table of the Elements A-


• Appendix III: Units of Measure A-


• Independent Assortment A- Appendix IV: A Closer Look at Probability and


• Genetics Problems A- Appendix V: Answers to Critical Thinking


• Appendix VI: Answers to Self-Quizzes A-


• Chromosomes and Some Associated Traits A- Appendix VII: A Plain English Map of the Human


• Glossary G-


• Index I-


• to population density Some natural population controls are related


• Problems 25.3 Ecological “Footprints” and Environmental


• Everyone has an ecological footprint


• Some resources are renewable but others are not


• Pollution can result from human activities


• 25.4 Assaults on Our Air


• Air pollution has damaged the ozone layer


• 25.5 Global Warming and Climate Change


• What will climate change mean for us?


• 25.6 Problems with Water and Wastes


• Water issues affect 75 percent of humans


• Managing solid wastes is another challenge


• 25.7 Problems with Land Use and Deforestation


• and other scarce resources Feeding and housing billions of humans requires land


• Deforestation has global repercussions


• 25.8 Moving toward Renewable Energy Sources


• There are growing issues with fossil fuels


• Can “green” energy sources meet the need?


• What about nuclear power?