Respiratory System bSlide 2Slide 3LungsLung LobesLungSlide 7Slide 8Alveoli StructureSlide 10Slide 11Slide 12Type IType II aka Surfactant Secreting CellSlide 15SurfactantSurfactant Secreting CellSlide 18MacrophagesMacrophages “Eat” Debris & BacteriaSlide 21Slide 22Alveoli FunctionSlide 24Gas ExchangeHighly VascularizedAlveoliAlveolar CapillariesSlide 29Slide 30Slide 31Slide 32Slide 33Respiratory MembraneDiffusion distanceSlide 36Slide 37Slide 38RespirationSlide 40VentilationSlide 42DiaphragmMuscles Associated with BreathingSlide 45Serous membranesSlide 47PleuraBreathingInhalationExhalationSlide 52Slide 53Slide 54Slide 55Systemic RespirationSlide 57Neural controlSlide 59Slide 60Smoking is the leading cause of death in AmericaLung diseaseSlide 63Slide 64EmphysemaSlide 66Slide 67Slide 68Slide 69Slide 70Slide 71PneumoniaSlide 73Slide 74HiccupSlide 76Pollution and Your LungsSlide 78Respiratory System bChapter 24Lungs•Gas exchange organs•Delicate structure of Airways, Alveoli, capillaries•Right lung–3 lobes–Superior, middle, inferior•Left lung–2 lobes–Superior, inferior•Cardiac notch accommodates heart•Located in separate pleural cavitiesLung LobesLungAlveoli Structure•3 cell types•Epithelial Cells (type I)–Simple Squamous•Alveolar macrophages–Phagocytic WBC–Engulf inspired particles (dust)•Surfactant secreting cells (Type II)–Secrete surface active agent–Surfactant•Decreases intra-alveolar surface tension•Prevents alveolar collapseAlveoli StructureType IExchange gas with capillariesType II aka Surfactant Secreting CellRegeneration & surfactant productionSurfactantSurfactant Secreting CellMacrophagesMacrophages “Eat” Debris & BacteriaMacrophages eating sootMacrophageAlveolar PoresAlveoli StructureAlveoli Function•Simple squamous epithelium•Provide favorable diffusion surface–Small diffusion distance–Large surface area•300 million alveoli produce ~760 sq ft•Contribute to respiratory membraneGas Exchange•Gas exchange between air in alveoli & blood in capillaries•High blood perfusion to lungs•Alveolar capillaries surround alveoliHighly VascularizedAlveoliAlveolar CapillariesAlveoliAlveolar CapillariesRespiratory Membrane•2 cell layers of simple squamous–Alveolar epithelial cells–Capillary endothelial cells•Total diffusion distance–~0.1 – 1.5 microns•Efficient diffusion distance–Carbon dioxide diffuses into alveoli–Oxygen diffuses out of alveoliDiffusion distanceRespiratory MembraneRespiration•Breathing•Cycle of inhalation & exhalation•Involuntary contraction of diaphragm•Driven by change in pressure•Body creates negative pressure in body cavity•Regulated chemically –Amounts of CO2 in blood streamRespiration•Ventilation–Movement of air in & out of lungs•Systemic respiration–Exchange of gas between inhaled air & blood•Cellular respiration–Cell use of O2 to make ATPVentilation•Involves changes in pressure to move air in & out•Respiratory muscles•Diaphragm–Increases volume of thoracic cavity by “dropping” floor •External intercostal–Elevate ribs expanding chest cavity•Internal intercostal–Depress ribs to reduce volume of thoracic cavityDiaphragmMuscles Associated with BreathingSerous membranes•Parietal pleura–Lines pleural cavity•Visceral pleura–Covers lung•Ventilation–Movement of chest wall–Membranes adhere to each other–Movement of chest wall “pulls” lungs openVentilationPleuraBreathing•Inhalation–Rib cage expands- increases volume–Diaphragm contracts- increases volume–Creates negative pressure in lungs–Air rushes in•Exhalation–Rib cage contracted- decrease volume•Internal intercostals contract•Inhalation muscles relax–Diaphragm relaxes- decrease volume–Increases pressure IN lungs –Air rushes outInhalationExhalationBreathingBreathingRespirationhttp://chickscope.beckman.uiuc.edu/explore/embryology/day15/focuson_humans.html - blankSystemic Respiration•Exchange of gas across respiratory membrane •Passive transport down concentration gradientSystemic RespirationNeural control•Blood gas levels monitored by breathing control centers•Adjust breathing to meet body’s needsSmoking is the leading cause of death in AmericaLung disease•Lining of respiratory surface- delicate•Molecules bind & impair function•Protected by–Mucus–cilia•Lung cancer•emphysemaEmphysema•Alveoli over-inflate because of a breakdown of alveolar walls•Resulting decrease in respiratory function•3 million americans –15th most common chronic condition•Leading cause–Cigarette smokingEmphysemaEmphysemaPneumonia•Inflammation of lung tissue•Bacteria•VirusesHiccup•Spasm of diaphragm•Rush of air into glottis = “hic”•Causes–Irritation to diaphragm–Pressure to phrenic nerve•Why?–Possibly vestigial function–Circulate water over gillsPollution and Your