Function of Respiratory SystemPermit gas exchange between air and circulating bloodConduct air to and from exchange surfacesProtect respiratory surfaces from dyingDefend respiratory system from pathogensPermits verbal communicationAssists in regulation of blood volumes, bp and body phDivisionsThe conducting partConducts gases to and from place where exchange occursRespiratory partPortion where exchange of gases occursComponents of conducting partNoseNasal cavity and nasal sinusesPharynxLarynxTracheaBronchi/ bronchiolesPrimary bronchi (part are outside lungs called exobronchi?)Break down into bronchiolesFirst place where gas exchange can take placeAlveolar duct…Function of conducting part of respiratory systemConveying gases to and fro the exchange surfaceWarming the incoming airOlder people can wear masks to give more time to warm the airFiltering the incoming air (removes particulate matter)Some can still get down there but want to remove the majorityHumidifying the incoming airRespiratory EpitheliumLines conducting portions of respiratory systemStructurally it is a ciliated psuedostratifed columnar epithelium that contains goblet cellsGoblets cells produce mucus (a precursor to mucus)Columnar cells that have cilia on their surface that can move the mucusMucociliar esculator- towards the oral cavity and moves mucus to it can either be swallowed or spit outSmoking can impair it and destroy it so cannot workHowever if you stop smoking it can fix itselfStem cells (basal cells)- can repair itself or form new goblet cells or columnar cellsMucociliary escalatorWashes particles toward oral cavityHeat ExchangeGoes through nasal cavity to warm it and humidfy itNose and Nasal CavityExternal naresOpen to nasal cavity at vestibuleVestibule guarded by coarse hair, can be trimmed, but should not be pulled outCan take bacteria from base of nose to base of skull and cause meningitisNasal cavitySuperior, middle and inferior conchaNarrow grooves underneath concha are called meatusesCreates a vortex of swirling air and gives time to warm up and add humidityNasal cartilagesAdd traction to nasal cartiliages and open pathways during sporting events for a more open path wayPathExternal nares conchae nasopharynx entrance to auditory tube oropharynx epiglottis laryngopharynxOlfactory RegionOlfactory cells that allow you to perceive smells and connect to olfactory bulbSmall for humans and larger for dogs/catsComponents of Nasal CavityHard palateNasal and oral cavitiesSoft palateSeparates the nasal and oral cavities duringInternal NaresPharynxFibromuscular tube shared by digestiveLarnyxSkeleton made of cartilage3 paired cartilagearytenoid cartilagecorniculate cartilagecuneiform cartilage3 unpairedepiglottiscricoid cartilagethyroid cartilageligamentsconnect to hyoid boneconnect to cricoid cartilagecontinues on and becomes the tracheac shaped rings with closed part of c facing anteriorVoiceLonger strings produces a deeper soundMalesShorter strings produce a higher soundCaused by vibrationCauses sounds by tongue allows speechVocal cordsThe glottis can open or closeTracheaTubular structure from CV6 to TV6Main strength of wall provided by C rings of cartilageTo keep it openTracheal cartilageStiffen tracheal wall s and protect airwayPosterior wall of smooth muscle, not cartilage, allowing food passage through esophagusSplits into primary bronchiTo secondary bronchi/ tertiary bronchiAspiration- when objects are inhaled into the tracheaOften occurs in the right firstPrimary BronchiRight and left primary bronchiTrachea braches within mediastiumLobesSeparated by fissureRight lung has three lobesSuperior, middle, and inferiorLeft lungs has twoInferior and superiorLung SurfacesCostal surfacesMediastinal surfacePulmonary BronchiPrimary bronci brach to form secondary or lobar bronchiSecondary form tertiaryBranches 23x approx in a lungNo more cartilage in terminal bronchiolesLead to lobulesBronchiolesUsually 1 mm in diameterNo cartilage in walls, mainly smooth muscle for support,Reduced numbers of goblets cells in epithelium and no glands in wallsVariety of sies 2 important typesTerminal bronchioles, slightly thicker walls,Respiratory bronchiolesAlveolar organizationArrangement between alveolar ducts, sacs, and alveoliNo possibility for gas exchange in terminal bronchiolesveins lie in septum not with bronchioles (intersegmental)arteries follow bronchiolescell types of alveoli2 epitheliumtype 1- just sit there, simple squamous not mitosistype 2- pneumocytes septal cell, can undergo mitosisproduce surfactant- reduces surface tension so when we exhale they don’t collapsecoasts foreign material to be digested by alveolar macrophages1 phagocyte (dust cells)macrophages-monitor alveolar epitheliumengulf foreign particles- organic or inorganicgas exchange occurs in the capillary in the alveolar septum (wall)Respiratory membrane4 layersblood gas barrierco2 out and o2 inpleural cavitysurrounds each lunglined by pleura, a serous membrane (secretes a watery fluid)visceral pleura and parietal pleurapleural fluidpleurisyPulmonary ventilationMovement of air into and out of lungsRespiratory musclesPrincipal respiratory muscles are the diaphragm and intercoastal musclesContraction of diaphragm increases verticalAs the ribs are eleveated and the diaphragm is contract, the volume of the thoracic cavity increases and air moves intoAccessory Respiratory MusclesIncrease depth/ assist the diaphragm and intercoastal mmInspirationRibs move upward and outward and diaphragm moves downExhalationDiaphragm moves up and ribs moves downRespiratory changes at birthFetal lungs are fluid-filled and collapsedPostnatal lungs are inflated and never collapse fully, as long as surfactant levels are normalRespiratory distress syndromeRespiratory with ageElastic tissue deterioratesLowers vital capacityMovement of thoracic cage are restrictedArthritic changesDecreased flexibility of costal cartilagesACommonly used termHyperpneaForced breathing, as in taking deep breaths or during vigorous exerciseEupneaQuiet breathing, as when sitting,TachyneaVery rapid breathing (more than 20x a minute)DyspneaDiffuculty breathingApneaNot breathingCh 24 Respiratory System 04/08/2010Function of Respiratory System-Permit gas exchange between air and circulating blood-Conduct air to and from exchange surfaces-Protect respiratory surfaces from dying-Defend respiratory system from pathogens-Permits verbal communication-Assists in regulation of