“以器官系统为中心”的医学教学模式是国际医学教育的趋势。本系列书是世界著名医药卫生出版集团爱思唯尔公司出版的一套“以器官系统为中心”的医学基础课程教材。该套教材第1版出版后受到世界各地许多医学院校的欢迎，并被多家进行“以器官系统为中心”教学的医学院校选定为教材。第2版根据第1版出版后教师和学生的反馈意见，结合医学知识的更新进行了全新修订。在编写内容上，该系列教材强调基础与临床的整合。每一章节都是围绕着一个临床病例展开，通过对病人问题的呈现以及解决过程引出对相关知识的探究，从而使与器官系统结构、功能以及疾病相关的重要的基础医学知识得到了完善的整合。在版式安排上，图框中的病例资料与正文中的医学知识完美匹配，一步一步地激起读者的求知欲望。本册为《呼吸系统》。

1 INTRODUCTION 1

 Introduction 2

 What is respiration? 2

 The need for respiration 2

 Diffusion in respiration and the circulation 3

 Timing in the circulation and respiration 3

 Basic science of respiration 3

 Drugs 9

2 STRUCTURE OF THE RESPIRATORY SYSTEM,RELATED TO FUNCTION 11

 Introduction 12

 The upper airways 12

 The intrathoracic airways 15

 Blood vessels 18

 Pulmonary hypertension 18

 The lymphatics 19

 The nerves 19

 Gross structure of the respiratory system 19

 Pleurisy 20

 The diaphragm and chest wall 20

 How breathing is brought about 22

 Embryology 23

 Air-conditioning 24

 Metabolic activity 26

 Metabolism of circulating biologically active substances 27

 Non-respiratory functions 27

3 ELASTIC PROPERTIES OF THE RESPIRATORY SYSTEM 29

 Introduction 30

 Intrapleural pressure (Ppl) 30

 Static lung compliance (CL) 31

 The effect of disease 32

 The physical basis of lung compliance 32

4 AIRFLOW IN THE RESPIRATORY SYSTEM 41

 Introduction 42

 How airflow is brought about 42

 The nature of airflow 43

 The major determinant of flow - radius 43

 Airways resistance and obstructive pulmonary disease 43

 The clinical situation 45

 Sites of airways resistance 46

 Asthma and airways smooth muscle 48

 Bronchomotor tone 49

 Pharmacological treatment of asthma 50

 Clinical definitions 50

 Bronchitis and mucus 52

 Emphysema and radial traction 53

 Intrapleural pressure and cough 54

 Clinical tests for changes in resistance 57

 Work of breathing 57

5 VENTILATION OF THE RESPIRATORY SYSTEM: THE IMPORTANCE OF ITS LACK OF UNIFORMITY IN DISEASE 61

 Introduction 62

 Spirometric abnormalities in disease 63

 Uneven distribution 64

 Dead space. 64

 Alveolar dead space in disease 65

 The Bohr equation 66

 Factors affecting physiological dead space 68

 Alveolar ventilation and respiratory exchange 68

 The alveolar gas equation 69

 Distribution of inspired gas 69

 Other factors influencing distribution 72

6 GAS EXCHANGE BETWEEN AIR AND BLOOD:DIFFUSION 77

 The path from air to tissue 78

 Lung disease and diffusion 79

 Fick's Law of Diffusion 79

 Measuring transfer factor 82

 Treating diffusion difficulties 83

 Carbon dioxide and other gases 83

7 THE PULMONARY CIRCULATION: BRINGING BLOOD AND GAS TOGETHER 85

 The functions of the pulmonary circulation 86

 The anatomy of the pulmonary circulation 86

 Matching ventilation and perfusion 89

 Distribution of blood flow through the lungs 89

 Regional differences in ventilation in the lungs 94

 Ventilation/perfusion matching and its effect on blood

 O2 and CO2 content 95

 Shunt 97

8 CARRIAGE OF GASES BY THE BLOOD AND ACID/BASE BALANCE 99

 Introduction 100

 Oxygen transport 100

 Dissolved oxygen: do we really need Hb and why

 keep it in red cells? 108

 Carbon dioxide transport 109

 Acid-base balance 113

9 CHEMICAL CONTROL OF BREATHING 119

 Introduction 120

 Oxygen lack 120

 Carbon dioxide excess 125

10 NERVOUS CONTROL OF BREATHING 129

 Introduction 130

 The rhythm generator 131

 Pattern of breathing in COPD 132

 The respiratory 'centres' 133

 The medullary groups 133

 Conscious control of breathing 134

 Respiratory muscle innervation 135

 Neuromuscular disorders 137

 Vagal reflexes 137

 Dyspnoea 140

 Other reflexes 140

11 LUNG FUNCTION TESTS: MEASURING DISABILITY 143

 Introduction 144

 Spirometry 144

 Flow measurements 145

 Plethysmography 145

 Lung mechanics 146

 Transfer factor (diffusing capacity) 147

 Blood gases 148

 Gas washouts 148

 Exercise testing 150

 Challenge tests 151

 Appendix: some basic science 153

Glossary 159

Index 165