Slide 1What is respiratory system responsible for?Functional AnatomyThe NoseRespiratory Mucosa of NoseSinusesDiseasesPharynxLarynxTracheaTracheaSlide 12Main BronchiLungsIn LungsAlveoli – Site of Gas ExchangeRespirationMechanics of BreathingInspirationExpirationExpiration in diseasedRespiratory Volumes and CapacitiesGas TransportGas transportSystemic ExchangeAlveolar Gas ExchangeSmokers vs Non-smokersSlide 28Chapter 22THE RESPIRATORY SYSTEMWHAT IS RESPIRATORY SYSTEM RESPONSIBLE FOR?•Cells use of oxygen•Can’t do without it!•Waste products of aerobic respiration•CO2•Cardiovascular and respiratory systems share job of providing O2 and removing CO2•Gas exchange vs transportFUNCTIONAL ANATOMY•Nose, pharynx, larynx, trachea, bronchi, smaller branches and lungs which contain alveoli•Gas exchange with blood only happens in alveoli•All other structures just conducting passagesFigure 13.1THE NOSE•Only externally visible part•Nostrils or nares – air enters•Nasal cavity – inside•Nasal septum•Olfactory receptors•Where are they?Figure 13.2RESPIRATORY MUCOSA OF NOSE•Lines nasal cavity•Covers network thin walled veins – blood flow warms air•Nose bleeds?•Moisten air, trap bacteria and debris•Lysozymes•Ciliated cells •Sluggish on cold days•Conchae – SA and turbulence•Palate – malformation?Figure 13.2SINUSES•Paranasal sinuses – in frontal, sphenoid, ethmoid, and maxillary bones•Lighten skull•Resonance chamber for speech•Produce mucus•Nose blowingFigure 13.2DISEASES •Sinusitis – sinus inflammation•Passageways between sinus and nasal cavity blocked - mucus or infectious matter•Sinus headache•Rhinitis – cold virus or allergens cause inflammation of nasal mucosa•Nasal congestion and drip•Mucosa continuous throughout tract – leads to infections in nasolacrimal ducts and sinusesPHARYNX•Muscular passageway – throat•Food and air•Nasopharynx •Eustachian tubes drain here –leads to what?•Pharyngeal tonsil - adenoid•Oropharynx•Palatine tonsils•Lingual tonsils•Tosillitis•Laryngopharynx•Leaves here and enters larynx•Food enters esophagusFigure 13.2LARYNX•Voice box•Routes food and air•Formed by 8 hyaline cartilages – largest thyroid cartilage – adam’s apple•Epiglottis – elastic cartilage •When swallow, larynx pulled up, epiglottis tips, lid over larynx•Not swallowing, larynx open•What kind of epithelial tissue?•Cough reflex – doesn’t work when unconscious•Vocal chords – vibrate with air movementFigure 13.2TRACHEA•Windpipe•To 5th thoracic vert.•Rigid – walls reinforced with C shaped rings – hyaline cartilage•Rings•Open part to esophagus allows for expansion when swallow•Solid part keeps trachea open with pressure changes due to breathingFigure 13.3TRACHEA•Lined with ciliated mucosa•Beat continuously upward•Dust and other debris•Swallow or spat out•Smoking inhibits and destroysMAIN BRONCHI•Branch from trachea into each lung•Rt. Bronchus is wider shorter and straighter•Choking•Air is warm, cleansed, and humidifiedFigure 13.1LUNGS•Occupy entire thoracic cavity except what?•Divided into lobes•Rt – three lobes•Lf – two lobes•Surface covered with visceral pleura•Walls of thoracic cavity – parietal pleura•Pleural space filled with pleural fluid•Two layers move smoothly, but resist being separated•Lungs held tightly to wallFigure 13.4aIN LUNGS•Bronchi divide into smaller pathways•Smallest conducting pathway is bronchioles•Bronchioles eventually terminate in alveoli•Alveoli only site of gas exchange•Lungs mostly air spaces•Lungs only weigh 2.5 lbsFigure 13.5ALVEOLI – SITE OF GAS EXCHANGE•Pulmonary arteries and veins – down to capillaries, line sacs, simple squamous epithelial•Alveolar sacs – 3 cell types• simple squamous epithelial•Surfactant secreting cells – coats lining of alvelous to prevent collapse•MacrophagesRESPIRATION•Pulmonary ventilation (breathing)– air movement in and out of lungs refreshing gas sacs (alveoli)•External respiration – gas exchange, O2 loading, CO2 unloading between pulmonary blood and alveoli.•Between blood and body exterior•Respiratory gas transport – O2 and CO2 transported to/from lungs and tissue cells of body via blood•Internal respiration – systemic capillaries, gas exchange between blood and tissue cells.Figure 13.4aMECHANICS OF BREATHING•Volume changes lead to pressure changes, which lead to the flow of gases to equalize the pressure.•In large, volume, gas molecules will spread out, reduced pressure•In smaller volume, gas molecules closer together, greater pressure•Intrapleural pressure is normally negative, prevents lung collapseINSPIRATION•Inspiratory muscles – diaphragm and external intercostals•Contract, enlarge thoracic space•Lungs adhere to thoracic cavity•Intrapulmonary volume increases, decrease in pressure, sucks air in until intrapulmonary pressure equals atmospheric pressureFigure 13.7aEXPIRATION•Passive process in healthy•Inspiratory muscles relax•Thoracic and intrapulmonary space decreases•Intrapulmonary pressure greater than atmospheric – gas flows out!Figure 13.7bEXPIRATION IN DISEASED•Spasms of bronchioles (asthma) or clogged with mucus or fluid (pneumonia)•Expiration active process•Internal intercostals compress•Abdominal musclesFigure 13.7bRESPIRATORY VOLUMES AND CAPACITIES•Factors affecting resp. capacity – size, sex, age, physical condition•Tidal Volume (TV)– normal breathing, about 500 ml in and out with each breath•Inspiratory Reserve Volume (IRV) – amount of air taken in forcibly, about 2100-3200 ml•Expiratory reserve volume (ERV) – forcibly exhaled air, about 1200 ml•Residual Volume – air that remains in lungs after forced exhale, about 1200 ml•Allow for continuous gas exchange•Vital Capacity (VC) – Total amount of exchangeable air. •TV+IRV+ERV•About 4800 ml in healthy young maleFigure 13.9GAS TRANSPORT•Oxygen exchange•About 98.5% O2 carried by Hb, 1.5% dissolved in blood plasma•When O2 bound to Hb called oxyhemoglobin (Hb O2), no O2 call deoxyhemoglobin•When all Hb are saturated = 4 O2 molecules, 75% = 3 O2 molecule, etc•First O2 molecule binds Hb, causes greater affinity for O2•O2 not dropped off in equal amounts to all tissues•PO2 Temperature – increase promotes O2 unloading•Bohr effect – active tissues produce CO2, raises