Respiratory System

What is the function of the Respiratory System?
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Terms in this set (105)
Respiratory macrophages in airways trapDust and pathogensOther functions of the Respiratory Tract:Vocalization, water and heat loss.Venous return:Pulmonary circulation is returned to left heart.Activation of plasma proteins and enzymes as theyMove through the pulmonary circuit.Anatomy of the Respiratory Tract exists of?Chest wall, Respiratory zone, Conducting zone, Upper airway.Chest wall includesRib cage, thoracic vertebrae, connnective tissue, diaphragm, intercostals, muscles that drive inspiration, and other muscles of the neck/throat and thoraxUpper airway includesNasal cavity, oral cavity and pharynxConducting zone deals withconducting air, moving the airConducting zone includesLarynz, trachea, bronchi, bronchiolesRespitory zone includesalveoliChest wall functionsForms a continuous barrier around the lungs, it is the plural membraneSerous membrane is filled withSerous fluidParietal layer (body wal)Closest to the chest wallVisceral layerClosest to the lungsInterpleural space is filled withInterpleural fluidThe visceral and parietal layers resist pulling away from each other due to tension and pressure, this ensures that the lungs willinflate and deflate as directed by the inspiratory muscles that change the volume within the thoracic cavity.Upper airway functionsPassageway for air and food, contains mucusAirways are held open byCartilage (except for the bronchioles)What is the order of the bronchi as they get deeper into the lungsPrimary bronchi, secondary bronchi, bronchioles, terminal bronchiolesBronchioles containSmooth muscle so they will respond by undergoing bronchoconstriction or bronchodilationConducting zone is lined withMucus and ciliaGoblet cells secreteMucusMucus escalatorCilia will propel dust filled macrophages up to pharynx where they will be swallowed (enter the esophagus)Cilia become paralyzed byTobacco smokeIn the respiratory zone, air will enter theterminal bronchioles, alveolar duct, alveoliAlveoli are connected to one another byAlveolar poresAlveoli areAir filled sacks and are usually grouped in clustersStructure of alveoli maximizes surface area exposed to atmospheric air and maximizes exchange due to itsThin membraneWall of alveoli are a single layer of epithelial cellstype 1 alveolar cellsRespiratory membraneBasement membrane of capillary fused to the epithelial layer of the alveolar, location of gas exchangeAir moves into and out of th elungs by bulk flow, but what forces drive pulmonary ventilation?Changes in pressureAir will always flow toward area ofThe lowest presureIf pressure in lungs is lower than outside air,Air will move in (inspiration)If pressure in lungs is higer than outside air,Air will move out (expiration)What are the four pressures involved in Pulmonary Ventilation?Atmospheric pressure, Intra-alveolar pressure, intrapleural pressure, and Transpulmonary pressureAtmospheric pressure (Patm)Pressure outside airAtmospheric pressure (Patm) normal pressure equals760 mmHgIntra-alveolar pressure (Palv)Pressure of air inside the alveoliAt rest (neighter inspiration or expiration)Palv=PatmWhen Palv>PatmExpirationWhen Palv<PatmInspirationLungs do not completly empty after expiration, the air that remains is termedThe funtional residual capacity (FRC)Intrapleural pressure (Pip)Pressure inside the pleural spacePressure changes as distance betweenThe parietal and visceral layers changeThe default relaxation position for the chest wall is toExpandThe default relaxation position for the lungs is toCollapseWhat keeps the visceral and parietal layers tightThe surface tension within the insterpleural spaceAt rest-4mmHg, to remain negative this space must be air tightIntrapleural pressure is alwaysless and Palv and negative during normal breathingWithout the negative pressureThe lungs would collapse and the chest wall would expandPneumothoraxClinical term when air gets into intrapleural space caused by trauma or diseaseTranspulmonary pressureThe difference between the intra-alveolar pressure and the intraplural pressure (Palv-Pip); measures the distending pressure across the lungsAs transpulmonary pressure increasesThe lungs will inflateAs transpulmonary pressure decreasesThe lungs will deflateThe pressure gradients develop as a result ofSkeletal muscle contractionMuscle contraction changes the volume inside theThoracic cavityDecrease the volume of any container, and the pressure willincreaseInpiration is aActive process, requires ATPDuring inspiration the diaphragm will contract to become more flat and willincrease the volume of the chest cavityDuring inspiration the intercostals will contract to widen the chest cavity which willincrease the volume of the chest cavityDuring inspiration the increase volume will decrease the pressure, creating a gradient between the lungs and the atmosphere causingAir to flow into the lungHow is the muscle stimulated to contract?By a neuromuscular junction, ACH will cause Ca++ release->crossbridge cyclingExpiration isPassive process, triggered by relaxation of the inspiratory skeletal muscles (recoil)During expiration the diaphragm will relax (more curved) decreasingthe volume of the chest cavityDuring expiration the intercostals will relax and narrow the chest cavitydecreasing the volume of the chest cavityMechanism for relaxationno action potential, rememver muscles will only respond to excitatory signalsContration strength on inspiratoin can be regulated bydeeper breathing reqired by stronger contractionMesurement for air flowFlow=Patm-Palv/R(resistance)R(resistance) is caused byThe instrinsic resistance of the airway (air needs to get through the upper airway and conducting zones prior to entering alveoli)In a normal individual the resistance isLow2mmHg is a larg enough gradient tomove air into and out of the lung(Patm-Palv)Diameter of the lumen of the bronchioles, bronchoconstrictionWould increase resistanceDiameter of the lumen of the bronchioles, bronchodilationWould decrease resistanceDiameter of the lumen of the bronchioles affected byANS, hormones, and drugsParasympathetic driveBronchoconstrictionSympathetic driveBronchodilationHistamine>bronchoconstrictionIncreased carbon dioxide>bronchodilationMucus quality, thin mucusWould lubricate pathway, decrease resistanceMucus quality, thick mucusWould hinder air movemnt, increase resistanceFactors that increase resistanceDiseases that may narrow the airway and may alter compliance;the ease at which the lungs can stretchIncrease compliance is favorable,requires the inspiratory muscle to do less workCompliance (between inspiration and expiration)=change in volume/Palv-PipFactors tha affect complianceThickness of alveolar epitheliumWhat causes thickeness of alveolar epitheliumScares and inflammatory responsePulmonary surfactantDitergent like substance that allows the alveoli to re-inflate after collapse (only in babies born before 37weeks)Infant Respiratory Distress SyndromePremature babies who are deficient in surfactant will struggle to re-infalte alveoliSpirometryTechnique that can measure pulmonary function, it can help diagnose respiratory diseasesSpirometerDevice that measures volume of air moved by the lungsAsthmaSpastice contratoins of the bronchiolesAsthma increases resistance due toVasoconstriction, inflammation of bronchiole walls, and thickening of mucsus due to inflammatory responseAsthma causesAcute/temporary flare-upsClinical signs of asthmaDyspnea (difficulty creathing), wheezing, can be caused by a hypersensitivity to allergensAsthma treatmentBronchodialators and corticosteriodsChronic Obstructive Pulmonary Disease (COPD)Clinical signs are similar to asthma by this condition is chronic