Respiratory System (2024) PDF

The Respiratory System 백은주 magicmine / Getty Images 031-219-5042 Ajou University School of Medicine [email protected] Eun J...

The Respiratory System 백은주 magicmine / Getty Images 031-219-5042 Ajou University School of Medicine [email protected] Eun Joo Baik MD PhD r [email protected] From Quora 1  Contents 학습목표 I. Overview - Function & Structure of respiratory system II. Organization of the respiratory system - Airway ; Alveolar-capillary unit; Surfactants; Bronchial innervation III. Ventilation(환기) - Lung volume & capacity; Compliance; Work of respiration IV. Pulmonary Circulation(폐순환) V. Transport of O2 and CO2 VI. Regulation of respiration(호흡조절) -Central & peripheral chemoreceptor 2  I. Introduction: 우리는 왜 호흡이 필요한가? R A. Respiration 호흡 External respiration(외호흡) Internal respiration (내호흡) B. Basic process of Repiration 기본적인 호흡과정 1) 폐환기(Pulmonary ventilation); pumping machinery (lung mechanics) 2) Diffusion of O2 and CO2 ; between the alveoli and the blood 3) Transport of O2 and CO2 ; to and from the cells (gas transfer) 4) Regulation of ventilation 3 C. Functions of the respiratory system 1) Pulmonary respiration 폐호흡 : O2 uptake(250 ml/min) 및 CO2 discharge (200 ml/min) 2) Acid-base balance) - Producing acid from CO2 and indirect discharges of H+ CO2 + H2O ⇄ H2CO3 ⇄ H+ + HCO3- 3) Pulmonary metabolism; metabolism of bioactive materials angiotensin converting enzyme, other bioactive substance 4) phonation: vocal cords 5) Immune response: 폐포 거식세포(alveolar macrophage) 6) Promoting venous return by respiration 4 II. Structure of Respiratory System  상기도Upper respiratory tract  Nose, nasal cavity, paranasal sinus, pharynx  하기도Lower respiratory tract  Larynx, trachea, bronchial tree, lung * URI upper respiratory infection 5 기도 1) Conducting zone 공기전도영역 Dead space; 호흡무효공간, 호흡사강 2) Respiratory zone 호흡영역 6 Trachea(기관)  a flexible, cylindrical tube about 2.5X12.5 cm  A ciliated mucous membrane with many goblet cells  C-shape hyaline cartilage Bronchial tree(기관지)  Primary bronchi  Bronchioles(기관세지)  Alveoli (폐포, 허파꽈리)and alveolar ducts  Cartilage, smooth muscle, ciliated epithelium and simple squamous epithelial cells 7 Pleura (늑막), Pleural cavity (늑막강) - The space inside the lung is filled with air. - The intrapleural fluid is found between the lungs and the thoracic wall. - Pneumothorax 기흉 8 횡격막(Diaphragm) - The most important respiratory muscle - Innervationed by phrenic nerves (C3 - C5), * fatal injury above C3 흡기(Inspiration)와 호기(Expiration) Respiration at rest - Inspiration ; active process: against Elastic recoil and surface tension - Expiration ; passive process by elastic recoil Forced respiration By L. Cardinale, 2012) 9 Heimlich maneuver increases the alveolar pressure (Palv) by the upward movement of the diaphragm, thus compressing the thoracic cavity to dislodge foreign objects in the airways. 09-RN-RES 10 Anatomic structures of the respiratory system 분지 영역(zone) 분지(branching) 평활근 연골 혈액공급 (0~20) Nasal and Oral - Upper cavity 비강 및 구강 airways 인두(pharynx) - 상기도 Air conducting zone 후두(larynx) - (기도: 공기전도영역) = 해부학적 무효공간 기관(trachea) 0 + ++ (anatomic dead space) 기관지(bronchi) Bronchial 1 ++ + Artery ++ 기관지동맥 종말세기관지 16 (dormi none 세기관지 (terminalonchioles) ent) (bronchioles) 호흡세기관지 (respiratory br.) 17 Respiratory zone Pulmonary (호흡영역) 폐포관(alveolar ducts) none none Artery (site of gas exchange) 폐동맥11 폐포낭(alveolar sacs) 23 Mucociliary Escalator; cleaning (1) Goblet cell : Fluidic mucous secretion 수액성의 점액분비 - Bronchitis 기관지염: thick mucus secretion increase * Cystic fibrosis 포낭성섬유증 : decreased fluidic secretion (2) Ciliated epithelium 섬모상피세포 - Ciliary movement 섬모운동(10-20 beats/min, 1 cm/min - Effect of smoking during several hours on ciliary movemnt 12 Alveoli 폐포 Alveolar-Capillary Unit: site of gas exchange - Alveola and capillary networks: ca. 1000 capillaries / alveolus - No. of alveoli: 300 – 500 million (한 쪽 폐 3-5억개) - Respiratory area : ca. 75 m2 (40X body surface  tennis court) - very thin (0.2 um) - alveolar pore 13 폐포-모세혈관 가스교환 경로 (Barrier to gas exchange) 폐포표면 액체층(The fluid lining of the alveolar surface)  폐포 상피세포 (Alveolar epithelium)  간질조직 (Interstitial space)  모세혈관 내피세포 (Capillary endothelium)  혈장 (Blood plasma in the capillary) 14 III. Respiratory Mechanics 호흡기계학 (1) Inspiration by inspiratory muscle; active process - overcome elastic recoil and surface tension - Negative pleural pressure - Weakness of inspiratory muscle by neurological and muscular disease (1) Expiration ; passive process - Elastic recoil - Maximal expiratory pressure ; airway resistance 15 III. Respiratory Mechanics 호흡기계학  Breathing, or ventilation  Inspiration (흡기)and Expiration(호기)  Inspiratory muscle 흡기근; 횡격막(Diaphragm)  Pressure of thoracic cavity 흉강의 압력 16 호흡기계학(Respiratory Mechanics) 폐용적 변화 Lung volume change 폐포압 Alveolar Pressure 늑막내압 Pleural Pressure 유속 Air flow Resting respiration Intra-alveolar Intrapleural pressure pressure 폐포내압 늑막내압 흡식(inspiration) -1 cm H2O -8 cm H2O 호식(expiration) +1 cm H2O -5 cm H2O 17 표면장력(Surface Tension)과 탄성(Compliance) 1)More pressure in inspiration due to surface tension Air-filled lung vs saline-filled lung 계면활성제(Surfactants) 2) Compliance 유순도 ΔV CL = -------- ΔP 18 Pulmonary Surfactant 표면활성물질 - Produced by type 2 alveolar cell - Detergent-like material (phospholipid phosphatidylcholine) ; about 4 cm H2O reduce surface tension  Surfactant increases not only the compliance, but also the stability of the alveoli - Lack of pulmonary surfactant -- Alveoli collapse spontaneously - Iinfant respiratory distress syndrome 신생아 호흡곤란증후군 19 Obstructive pulmonary disease 폐쇄성폐질환 vs Restrictive pulmonary disease 제한적 폐질환 천식(Asthma) 만성기관지염, 폐기종(Emphysema) 만성폐쇄성 폐질환 (Chronic obstructive pulmonary disease, COPD) vs Fibrosis 섬유화 20  Airway Resistance 기도저항 and Compliance 유순도 Resistances in series or in parallel 기도의 굵기와 기도 저항 직렬배열과 병렬배열 구조에서의 저항 차이 If the tubes are in series, Rtot = R1 + R2 + R3 = 3 + 3 + 3 = 9 cmH2O/L･sec If the tubes are in parallel, 1/Rtot = 1/R1 + 1/R2 + 1/R3 = 1/3 + 1/3 + 1/3 = 1 cmH2O/L･sec In expiration, more resistance increases than that in inspiration 흡기는 공기가 폐포로 들어가기 쉽지만 호기 공기가 나오려면 저항이 증가하게 21 됨다. Regulation of the airway diameters; Bronchial Innervation The diameter of the bronchi is controlled by the ANS(자율신경계). (1) Increased Sympathetic activity → Relaxation of the smooth musculature (Bronchodilatation 기관지이완) (2) Increased Parasympathetic activity →Contraction of the smooth musculature (Bronchoconstriction 기관기수축) * Non-nervous local factors affecting bronchial contraction - Pollen-induced asthma (Allergic asthma) - Smoking, Dust, Chemical irritants 22 Airway Resistance 기도저항 and Compliance 유순도 23  Compliance 유순도 FEV1 ΔV CL = -------- ΔP 24  IV. Pulmonary Function Test 폐기능검사  Spirometry  Respiratory volumes 폐용적 - Tidal volume(일회 호흡용적)  Inspiratory reserve volume(흡식예비용적)  Expiratory reserve volume(호식예비용적)  Residual volume(잔기용적)  Respiratory capacities 폐용량  Vital capacity(폐활량)  Inspiratory capacity(흡식용량)  Functional residual capacity(기능적 잔기용량)  Total lung capacity(총폐활량) 25  Measurements of Lung volume 1. Spirometry; 2. RV, FRC and TLC 1) Helium(inert gas) dilution technique (closed circuit method) 2) Nitrogen washout technique (open circuit method) 3) Body plethysmography 26  FEV1 Forced vital capacity (FVC): - FEV1 : Expiratory volumes within 1 sec. - FEV1 / FVC (%) : > 80 % in healthy person - Decreased in the patient with COPD - Due to increased airway resistance A. B. C. 27 Flow-volume loop Expiratory loop 1) FEV 2) PEFR( peak expiratory flow rate) 3) FEF50(Vmax50) 4) Vmax70 Inspiratory loop 28  The Work of Breathing 호흡일 The amount of work in breathing (inspiration) =  Transpulmonary pressure x  Lung volume At resting state; 1% of total consumed energy Even heavy exercise 3-5% 29  V. Gas Exchange in the alveoli 폐포에서 가스교환 : Matching of ventilation and perfusion 1. Ventilation 환기 1) Inspiratory gas with water vapor; warming with body temperature 2) Movement of gas under partial pressure 3) Distribution of pulmonary air; effect of gravity -10 cmH2O -5 cmH2O -2.5 cmH2O 30 2. Diffusion through respiratory membrane  Movement under partial pressure of Po2 and Pco2  Affecting factors on diffusion  Surface area, distance, gas solubility, difference of partial pressures  Alveolar gas and arterial blood gas  Analysis of arterial blood gas 동맥혈가스분석: Analyze the respiratory state and acid-base state 31 3. Pulmonary Circulation 폐순환 Pulmonary artery with venous blood ; low pressure and resistance. Large reservoir cf. Pulmonary hypertension Dual system: Pulmonary vessels and Bronchial artery Well-developed lymphatic system Effect of gravity Protection against Pulmonary edema From Draw it to know it 32 4. Relationships between ventilation and perfusion; matching or mismatching VQ ratio 33 VI. Transport of gas in the blood 가스운반 A. Transport of oxygen Oxygen (O2) is carried: - Physically dissolved in the blood.(1.5% of O2) - Chemically combined to hemoglobin. (98.5% of O2) * Other Factors Affecting O2 Transport Anemia, Hemoglobinopathy, Carbon Monoxide intoxication) * Cyanosis 청색증 34 Oxyhemoglobin dissociation curve 산소해리곡선 - Bohr’s effect 35 B. Transport of Carbon Dioxide (CO2) - Physically dissolved in the blood. - Chemically combined to blood proteins (carbamino compounds), and as bicarbonate. 1) CO2 is highly soluble in lipid. (nonpolar molecule) → moves more easily across plasma membrane → transported in the circulation more readily than O2 → PCO2 tends to remain more nearly normal than O2. (Hypoxia more than hypercapnea) 2) Transportation of CO2 in 3 ways Hypoxia 저산소증 Hypercapnea 과탄산증 36 VII. Regulation of respiration 호흡조절 A. Characteristics 1) Automatic respiratory rhythm 2) Somatic nerve into the respiratory muscle : involuntary and voluntary eg. Diaphragm: innervated by phrenic nerve (C3 - C5) (during awake and asleep state, even under anesthesia) B. Respiratory Center 호흡중추 - located bilaterally in the medulla oblongata and pons 37 C. Chemoreceptors regulating the respiration (1) CO2: The most powerful chemicals that influence alveolar ventilation. - Excess CO2 mainly (directly) stimulate the respiratory center itself. (2) H+: The second most powerful chemical stimulus to ventilation. - H+ mainly (directly) stimulate the respiratory center itself. (3) O2: The smallest effect on ventilation - on peripheral chemoreceptors in the carotid and aortic bodies. BBB Brain Blood Barrier 38  Control of the Inner Organ Autonomic Nervous System 백은주 031-219-5042 [email protected] r From Quora 39 Hypothalamus 시상하부 09-RN-RES 40 Somatic vs Autonomic 41 Neurotransmitters in the ANS 자율신경계의 신경전달물질 Autonomic Nervous System Sympathtic vs Parasympathetic Fight and Flight Rest and Digest Actions of the ANS 자율신경계 작용 Actions of the ANS 자율신경계 작용 Actions of the ANS 자율신경계 작용 Actions of the ANS on the heart and blood vessel Chronotropy Inotropy Actions of the ANS on blood pressure and blood fluid Actions of the ANS on the respiratory system Actions of the ANS on micturition Actions of the ANS on food intake (appetite)