Chapter 33RespiratorySystemTherespiratory system is composed of there-pharynx and larynx,and thelower respiratory tract isspiratory tract and the lung. The respiratory tractcomposed of the trachea,principal bronchi with theirincludes the nose, pharynx, larynx, trachea and prin-branches.The right and left lungs are the essential re-cipal bronchi (Fig. II-3-1).According to the clinicalspiratory organs.The primary function of this systempoint of view, it also can be divided into two parts.is to supply the body with oxygen and to get rid ofThe upper respiratory tract consists of the nose,excess carbon dioxideresultingfrom cellmetabolism.NoseNasal cavityOralcavityCavity of pharynxLaryngeal cavity-iracheaRight principal brongLeft principal bronchusSuperiorlobePulmonaryalveoliLeft lungRight lungInferiorlobeFig. II-3-1 The respiratory system·145G扫描全能王创建2
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·146PARTISPLANCHNOLOGYseptum.Theright and left nasal cavities open in frontthrough nares. And they communicate with the phar-Section 1Noseynx behind through the choanae.The nose is the first part of respiratory tract andthe organ of smell and phonation,it is composed of1. Nasal vestibulethe extermal nose,nasal cavity and paranasal sinuses.The anterior portion of the nasal cavity is calledI.External Nosethe nasal vestibule which is just inside the alae nasiand posteriorly limited by the limen nasi. It is linedIt is divided into theroot, back,apex ofnose,twoby skin containing hairs and sebaceous glands (Figalaenasi and twonares.The external nose is com-II-3-2)posed of bones and cartilages covered by the skin.Proper nasal cavityII . Nasal CavityEach cavity has a roof,a floor,a medial wall andIt is divided into right and left parts by the nasalFrontal sinuornasalconchaSphenoidal spnusMiddlenasal conchaSuperiornasal meatusInferiornasalconchaMiddlenasalmeatusLimennasPharyngenal opening of auditory tubeInferiornasalmeatusNasal vestibuleFig. II-3-2 The lateral wall of nasal cavitya lateral wall.Theroof is formed mainlyby the nasalThe nasal mucous membrane lines entirelythena-sal cavity, it contains many mucous glands and bloodbone,cribriform plate of the ethmoid bone.Thefloorvessels, so that the inspired air can be warmed andis formed bytheupper surface of thehardpalate inhumidified.The olfactory receptors lie in the mucousfront (two thirds)and the soft palate behind (onemembrane lining the upper portion of the nasal cavitythird)There are the superior,middle and inferior(above the level of superior nasal concha) where isnasal conchae which project from thelateral wall up-called the olfactory region (Fig. II-3-2) . The rest ofward todownward and subdividethenasal cavityintosuperior,middle and inferior nasal meatuses locatedmedial and lateral nasal wall covered by a thick glan-dular and vascular mucous membrane constitute thebelow corresponding concha.Above and behind thesuperior nasal concha there is the sphenoethmoidalrespiratoryregion.recess (Fig. Il-3-2).The inferior nasal meatus receives theterminationI.Paranasal Sinusesof the nasolacrimal duct.The middle nasal meatus,superior nasal meatus and sphenoethmoidal recessIn the bones around the nasal cavity there arereceive the openings of paranasal sinuses.some air cells called paranasal sinuses, they are theD扫描全能王创建口
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Chapter3RespiratorySystem.147.frontal sinus,maxillarysinus,ethmoidal sinusandcontinuous with that of the nasal cavity.So some-sphenoidal sinus. All these sinuses open into the nasaltimes the infection of nasal cavity may spread to thecavity and are lined by mucous membrane which isparanasal sinuses,resulting in sinusitis (Fig.I-3-3,4)Frontal sinuSphenoidal sinusEthmoidal sinusMaxillary sinusFig.-3-3 The projection of paranasal sinuses(a nterior view)Opening ofthemiddleethmoidal sinusOpening of themaxillary sinusFrontal sinusOpening of the sphenoidal sinusOpeningofthefrontal sinusSphenoidal sinusHIAOpening of thenasolacrimal ductPharyngeal openingofauditorytubeFig. I-3-4 The paranasal sinuses and opening of paranasal sinusesMaxillary sinusesFrontal sinusesThey lie in the frontal bone, and drain into theThey are large cavities in the bodies of the maxil-la.Theyaredrainedbyoneofmore openings into themiddlenasal meatusesD扫描全能王创建n
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.148.PARTIISPLANCHNOLOGYof thefourth,ffth and sixth cervical vertebrae.In themiddle nasal meatuses.adult, it is about 4-5 cm long. Above, it is closely re-lated to the hyoid bone and the root of tongue.Below,Ethmoidal sinusesit extends to the trachea at the level of the sixth cer-vical vertebra. Posteriorly it communicates with theThe ethmoidal sinuses are composed of a lot oflaryngeal part of pharynx.small irregular spaces within the ethmoid bone andThe larynx consists of a framework of cartilagescanbedivided into anterior,middle and posterior por-that are connected together by ligaments, membranestions.The anterior and middle sinuses open into theand joints. It also has a number of small musclesmiddle nasal meatuses.The posterior sinuses emptywhich move the cartilages. Some of them are import-into the superior nasal meatuses.ant in phonation and in closing the aperture of larynxduring swallowing, The larynx is lined with mucousSphenoidal sinusesmembrane which is continuous with that of pharynxabove and that of trachea below.They are located in thebody of the sphenoid boneand divided into right and left portions by a bony sep-I . Laryngeal Cartilages (Fig.tum. They open into the sphenoethmoidal recesses.II-3-5, 6)All sinuses are small at birth and usually enlargeto a certain extent during childhood and adolescenceSection2PharynxThyroid cartilageThe pharynx is the common channel for both al-It is the largest and comprises two laminae whichimentary(ordigestive)and respiratory systems,theare fused in front but divergent behind.At the fusedfood and air pathways cross each other in pharynxpart there is a median elevation termed the laryngeal(Fig.II -3-1).Further description of pharynx, see theprominence. There is the superior thyroid notch at thealimentary system.upper border of the fusing part. The posterior borderSection3.Larynxof each lamina is prolonged upward and downwardforming the superior and inferior cornu. The superiorThe larynx is a part of respiratory passage as wellcornu is connected to the greater horn of hyoid boneas the organ of phonation. It lies in the neck in frontwhile the inferior cornu joins to the cricoid CartilageHyoid boneEpiglottic cartilageThyrohvoidmembrarSuperiorcormuofthyroidcartilageArytenoid cartilageThyroid cartilageCricoarytenoid jointMediancricothyroid ligamentCricothyroid jointLamina ofcricoidcartilageTracheal cartilageFig. II-3-5 The laryngeal cartilages and joints (I)7扫描全能王创建
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Chapter 3Respiratory System149EpiglotticHyoid boneConus elasticusThyrohyoidmembraneVocal ligamentThyroid cartilageIntermembranouspart of theglottisConus elasticusIntercartilaginousCricoid cartilagepart of the glottisVocalprearytenoid cartilageB.superiorviewA.lateral viewFig. II-3-6 The Laryngeal cartilages and joints(1)II . Laryngeal Joints (Fig.Cricoid cartilageII-3-5, 6)It is ring shaped and composed of a lamina ofcricoid cartilage behind, a narrow arch of cricoidcartilage in front. The lamina articulates with the ar-Cricothyroid jointytenoid cartilages. The cricoid cartilage is at the levelof the sixth cervical vertebra and its lower borderIt is located between the inferior cornu of the thy-markes the ends of pharynx and larynx, and hence theroid cartilage and the lateral surface of cricoid carti-commencementof the esophagus and trachea.lage.It can be rotated around the coronal axis,so thatthe length and the tenseness of the vocal fold may be3.Arytenoid cartilageschanged.They are two small pyramids and articulate withCricoarytenoid jointthe superoposterior border of the cricoid cartilage.Each presents an apex above and a base below, theIt is located between the lamina of cricoid carti-base sends a vocal process forward for attachment oflage and the base of the arytenoid cartilage.When thethe vocal ligament and a muscular process laterallyarytenoid cartilage glide and rotate on the cricoid, ap-for muscular attachment.position and abduction of vocal folds can be occurred.Il .Laryngeal Ligaments4.Epiglottic cartilageand MembranesIt is a leaf-shaped elastic cartilage.Its upper end isbroad and forms the anterior portion of the aperture oflarynx.Its lower end is attached to theback of thyroidThyrohyoid membranecartilage. This cartilage covered by mucous mem-braneforms theepiglottis.Thelower partof posteriorsurface of the epiglottis project backward and formsIt is located between the superior border of thethyroid cartilage and the hyoid bone (Fig. II-3-5, 6)the epiglottic tubercle.D扫描全能王创建
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