Copyright The McGraw-Hill Companies, Inc. Permission required or reproduction or display.Chapter 16LectureOutline!espiration"#ncompasses $ related unctions% &entilation, gas e'change, and () utili*ation +cellular respiration,-.entilation mo&es air in and out o lungs or gas e'change with /lood +e'ternal respiration,"Gas e'change /etween /lood and tissues, and () use /y tissues is internal respiration"Gas e'change is passi&e &ia diusion16-3!espiratory 0tructures 16-40tructure o !espiratory 0ystem"1ir passes rom mouth to trachea to right and let /ronchi to /ronchioles to terminal /ronchioles to respiratory /ronchioles to al&eoli16-50tructure o !espiratory 0ystem continued"Gas e'change occurs only in respiratory /ronchioles and al&eoli +2 respiratory *one,"1ll other structures constitute the conducting *one "1re polyhedral in shape and clustered at ends o respiratory /ronchioles, li3e units o honeycom/16-60tructure o !espiratory 0ystem continued"Gas e'change occurs across the $44 million al&eoli +54-64 m) total surace area,-(nly ) thin cells are /etween lung air and /lood% 7 al&eolar and 7 endothelial cell16-7Conducting 8one"9arms and humidiies inspired air"Mucus lining ilters and cleans inspired air-Mucus mo&ed /y cilia to /e e'pectorated 16-9Physical 1spects o .entilation 16-12Physical 1spects o .entilation".entilation results rom pressure dierences induced /y changes in lung &olumes-1ir mo&es rom higher to lower pressure-Compliance, elasticity, and surace tension o lungs inluence ease o &entilation 16-13Intrapulmonary and Intrapleural Pressures".isceral and parietal pleurae normally adhere to each other so that lungs remain in contact with chest walls-1nd e'pand and contract with thoracic ca&ity16-14Intrapulmonary and Intrapleural Pressures continued"Intrapleural space contains a thin layer o lu/ricating luid16-150urace Tension +0T,"1nd elasticity are orces that promote al&eolar collapse and resist distension ":ungs secrete and a/sor/ luid, normally lea&ing a thin ilm o luid on al&eolar surace-;luid a/sorption occurs /y osmosis dri&en /y thus inc. pressure o air within al&eoli16-200uractant"Consists ophospholipids secreted /yType II al&eolar cells":owers 0T /y getting /etween H)( molecules, reducing their a/ility to attract each other &ia hydrogen /onding16-220uractant continued"Pre&ents 0T rom collapsing al&eoli "0uractant secretion /egins in late etal lie"Premies are oten /orn with insuicient suractant +2 !espiratory ?istress 0yndrome or !?0,-Ha&e trou/le inlating lungs"In adults, septic shoc3 may cause acute respiratory distress syndrome +1!?0, which decreases compliance and suractant secretion16-23Mechanics o @reathing 16-24Mechanics o @reathing"Pulmonary &entilation consists o inspiration +2 inhalation, and e'piration +2 e'halation,-1ccomplished /y alternately increasing and decreasing &olumes o thora' and lungs16-25Auiet @reathing"Inspiration occurs mainly /ecause diaphragm contracts, increasing thoracic &olume &ertically"Parasternal and e'ternal intercostal contraction contri/utes a little /y raising ri/s, increasing thoracic &olume laterally"#'piration is due to passi&e recoil16-26?eep @reathing"Inspiration in&ol&es contraction o e'tra muscles to ele&ate ri/s% scalenes, pectoralis minor, and sternocleidomastoid muscles "#'piration in&ol&es contraction o internal intercostals and a/dominal muscles16-27Pulmonary ;unction Tests"1ssessed clinically /y spirometry, a method that measures &olumes o air mo&ed during inspiration and e'piration"1natomical dead space is air in conducting *one where no gas e'change occurs 16-29Pulmonary ;unction Tests continued"Tidal &olume is amount o air e'piredB/reath in quiet /reathing".ital capacity is amount o air that can /e orceully e'haled ater a ma'imum inhalation-2 sum o inspiratory reser&e, tidal &olume, and e'piratory reser&e16-30Pulmonary ?isorders 16-32!estricti&e ?isorders"1re characteri*ed /y reduced &ital capacity /ut with normal orced &ital capacity-e.g. pulmonary i/rosis 16-33(/structi&e ?isorders"Ha&e normal &ital capacity /ut e'piration is retarded-e.g. asthma-?iagnosed /y tests, such as orced e'piratory &olume, that measure rate o e'piration16-34Pulmonary ?isorders"1re requently accompanied /y dyspnea, a eeling o shortness o /reath"1sthma results rom episodes o o/struction o air low thru /ronchioles-Caused /y inlammation, mucus secretion, and /ronchoconstriction-Inlammation contri/utes to increased airway responsi&eness to agents that promote /ronchial constriction-Pro&o3ed /y allergic reactions that release Ig#, /y e'ercise, /y /reathing cold, dry air, or /y aspirin16-35Pulmonary ?isorders continued"#mphysema is a chronic, progressi&e condition that destroys al&eolar tissue, resulting in ewer, larger al&eoli-!educes surace area or gas e'change and a/ility o /ronchioles to remain open during e'piration-Collapse o /ronchiole during e'piration causes air trapping, decreasing gas e'change-Commonly occurs in long-term smo3ers"Cigarette smo3ing stimulates release o inlammatory cyto3ines- 9hich attract macrophages and leu3ocytes that secrete en*ymes that destroy tissue16-3616-37a. low P() in tissues a&ors unloading" Ideally, H/-() ainity should allow ma'imum loading in lungs and unloading in tissues16-70('yhemoglo/in ?issociation Cur&e"Gi&es H o H/ sites that ha&e /ound () at dierent P()s-!elects loading and unloading o ()"?ierences in H saturation in lungs and tissues are shown at right"In steep part o cur&e, small changes in P() cause /ig changes in H saturation 16-71('yhemoglo/in ?issociation Cur&e continued"Is aected /y changes in H/-() ainity caused /y pH and temperature"1inity decreases when pH decreases +@ohr #ect, or temp increases-(ccurs in tissues where temp, C() and acidity are high- Causes H/-() cur&e to shit right and more unloading o ()16-7216-73#ect o ),$ ?PG on () Transport"!@Cs ha&e no mitochondria> canDt perorm aero/ic respiration-),$-?PG is a /yproduct o glycolysis in !@Cs"Its production is increased /y low () le&els"Causes H/ to ha&e lower () ainity, shiting cur&e to right16-74#ect o ),$ ?PG on () Transport"In anemia, total /lood H/ le&els all, causing each !@C to produce more ?PG";etal hemoglo/in +H/;, has ) g-chains in place o /-chains o H/1- H/; canDt /ind ?PG, causing it to ha&e higher () ainity" ;acilitates () transer rom mom to /a/y16-750ic3le-cell 1nemia"0ic3le-cell anemia aects 6-77H o 1rican 1mericans-H/0 has &aline su/stituted or glutamic acid at 7 site on / chains - 1t low P(), H/0 crosslin3s to orm a Kparacrystalline gelL inside !@Cs"Ma3es !@Cs less le'i/le and more ragile16-76Thalassemia"Thalassemia aects primarily people o Mediterranean descent-Has decreased synthesis o a or / chains> increased synthesis o g chains16-77Muscle Myoglo/in"Is a red pigment ound e'clusi&ely in striated muscle-0low-twitch s3eletal and cardiac muscle i/ers are rich in myoglo/in16-78Myoglo/in"Has only 7 glo/in> /inds only 7 ()"Has higher ainity or () than H/> is shited to e'treme let" !eleases () only at low P()" 0er&es in () storage, particularly in heart during systole16-79C() Transport16-80C() Transport" C() transported in /lood as dissol&ed C() +74H,, car/aminohemoglo/in +)4H,, and /icar/onate ion, HC($-, +E4H,"In !@Cs car/onic anhydrase cataly*es ormation o H)C($ rom C() = H)(16-81Chloride 0hit" High C() le&els in tissues causes the reaction C() = H)( H)C($ H= = HC($-to shit right in !@Cs - !esults in high H= and HC($- le&els in !@Cs"H= is /uered /y proteins" HC($- diuses down concentration and charge gradient into /lood causing !@C to /ecome more positi&e - 0o Cl- mo&es into !@C +chloride shit,16-82Chloride 0hit16-83!e&erse Chloride 0hit" In lungs,C() = H)( H)C($ H= = HC($-, mo&es to let as C() is /reathed out" @inding o () to H/ decreases its ainity or H=- H= com/ines with HC($- and more C() is ormed"Cl- diuses down concentration and charge gradient out o !@C +re&erse chloride shit,16-841cid-@ase @alance o the @lood"@lood pH is maintained within narrow pH range /y lungs and 3idneys +normal 2 E.F,"Most important /uer in /lood is /icar/onate- H)( = C() H)C($ H= = HC($-- #'cess H= is /uered /y HC($-"PidneyMs role is to e'crete H= into urine16-85#ect o @icar/onate on @lood pH16-861cid-@ase @alance o the @lood continued") maNor classes o acids in /ody%-1 &olatile acid can /e con&erted to a gas " e.g. C() in /icar/onate /uer system can /e /reathed out-H)( = C() H)C($ H= = HC($- -1ll other acids are non&olatile and cannot lea&e /lood"e.g. lactic acid, atty acids, 3etone /odies 16-871cid-@ase @alance o the @lood continued"1cidosis is when pH C E.$G> al3alosis is pH I E.FG"!espiratory acidosis caused /y hypo&entilation - Causes rise in /lood C() and thus car/onic acid"!espiratory al3alosis caused /y hyper&entilation- !esults in too little C() 16-881cid-@ase @alance o the @lood continued"Meta/olic acidosis results rom e'cess o non&olatile acids-e.g. e'cess 3etone /odies in dia/etes or loss o HC($- +or /uering, in diarrhea" Meta/olic al3alosis caused /y too much HC($- or too little non&olatile acids +e.g. rom &omiting out stomach acid,16-891cid-@ase @alance o the @lood continued"