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Ear final
 

Ear final

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    Ear final Ear final Presentation Transcript

    • EARDEVELOPMENT
    • DEVELOPMENT OF EAREXTERNAL EARSOUND COLLECTING ORGANMIDDLE EARSOUND CONDUCTING ORGANINTERNAL EARCONVERTS SOUND WAVES INTO NERVE IMPULSECONTAINS VESTIBULOCOCHLEAR ORGANCONCERNED WITH EQUILIBRIUM AND HEARING
    • DEVELOPMENT OF INTERNAL EAR1---OTIC PLACODE—THICKENING OF ECTODERMON EACH SIDE OF RHOMBENCEPHALONINVAGINATES AND FORMS---2---OTIC PIT3---OTIC VESICLE/OTOCYST PRIMORDIUM OF MEMBRANOUS LABYRINTH
    • DEVELOPMENT OF INTERNAL EAROTIC VESICLE1---VENTRAL COMPONENT a—SACCULE b---COCHLEAR DUCT2---DORSAL COMPONENT a---UTRICLE b---SEMICIRCULAR CANALS c ---ENDOLYMPHATIC DUCT—A DIVERTICULUM FROM THE VESICLE
    • DEVELOPMENT OF INTERNAL EAR• STATOACCOUSTIC GANGLION• GROUP OF CELLS WHICH BREAKS AWAY FROM THE OTIC VESICLE• ALSO RECEIVES CELLS FROM NEURAL CREST• SPLITS INTO---1—COCHLEAR PART• ---2---VESTIBULAR PART
    • DEVELOPMENT OF INTERNAL EARCOCHLEAR AND VESIBULAR PARTS SUPPLY THESENSORY CELLS OF—1—ORGAN OF CORTI2---SACCULE3---UTRICLE4---SEMICIRCULAR CANALS
    • DEVELOPMENT OF INTERNAL EAR• SACCULE COCHLEA AND ORGAN OF CORTI• TUBULAR OUTPOCKETING FROM THE LOWER END OF SACCULE– THE COCHLEAR DUCT• APPEARS IN THE 6th WEEK• PENETERATES THE SURROUNDNG MESENCHYME IN A SPIRAL FASHION• COMPLETES 2.5 TURNS AT THE END OF 8th WEEK• FORMS THE MEMBRANOUS COCHLEA
    • DEVELOPMENT OF INTERNAL EARSACCULE [ CONTD ]CONNECTION OF COCH DUCT WITH THESACCULE IS REDUCED TO A NARROW DUCTUSREUNIENSMESENCHYME SURROUNDING THE COHLEARDUCT DIFFERENTIATES INTO CARTILAGENOUSOTIC CAPSULE
    • DEVELOPMENT OF INTERNAL EAR• MEMBRANOUS LABYRINTH ENLARGES AND VACUOLES APPEAR IN CARTILAGENOUS CAPSULE IN THE 10th WEEK• VACUOLES BECOME CONFLUENT TO FORM PERILYMPHATIC SPACE• MEMBRANOUS LABYRINTH SUSPENDED IN A FLUID [ PERILYMPH ] IN THE PERILYMPHATIC SPACE• CARTILAGENOUS CAPSULE OSSIFIES TO FORM THE BONY LABYRINTH
    • DEVELOPMENT OF INTERNAL EARPERILYMPHATIC SPACE RELATED TO COCHLEARDUCT DEVELOPS INTO---1—SCALA VESTIBULI SEPARATED FROM THE COCHLEA BY THE VESTIBULAR MEMBRANE2---SCLA TYMPANI SEPARATED FROM THE COCHLEA BY THE BASILAR MEMBRANELAT WALL OF COCH DUCT REMAINS ATTACHEDTO THESURROUNDING CARTILAGE BY SPIRAL LIGAMENTMEDIAN ANGLE OF COCH. DUCT IS CONNECTED TO AND IS SUPPORTED BY A LONG CARTILAGENOUS PROCESS—THEMODIOLUS FUTURE AXIS OF COCHLEA
    • DEVELOPMENT OF INTERNAL EARSPIRAL ORGAN OF CORTIDIFFERENTIATES FROM CELLS IN THE WALLS OFCOCHLEAR DUCTGANGLION CELLS OF 8th NERVE MIGRATE ALONGTHE COILS OF COCHLEAFORMS THE SPIRAL GANGLIONNERVE PROCESSES EXTEND FROM THEGANGLION TO THE SPIRAL ORGAN WHERE THEYTERMINATE ON THE HAIR CELLS
    • DEVELOPMENT OF INTERNAL EARSPIRAL ORGAN OF CORTIEPITHELIAL CELLS OF THE COCHLEA FORM TWORIDGES---1—INNER RIDGE [SPIRAL LIMBUS ]2---OUTER RIDGEOUTER RIDGE FORMS 3—4 ROWS OF HAIRCELLS—SENSORY CELLS OF AUDITORY SYSTEMHAIR CELLS COVERED BY TECTORIAL MEMBRANE
    • DEVELOPMENT OF INTERNAL EARORGAN OF CORTI [CONTD]TECTORIAL MEMBRANE IS ATTACHED TO SPIRALLIMBUS AND ITS TIP IS ON HAIR CELLSORGAN OF CORTI FORMED BY—1-TECT MEMB ---2-HAIR CELLSIMPULSES RECEIVED BY THE ORGAN OF CORTIARE TRANSMITTED TO---SPIRAL GANGLIONFROM THERE TO CNS BY THE AUDITORY FIBRESOF 8TH CRANIAL NERVE
    • DEVELOPMENT OF INTERNAL EARUTRICLE AND SEMICIRCULAR CANALSSEMICIRCULAR CANALS APPEAR AS FLATOUTPOCKETINGS OF THE UTRICLECENTRAL PORTIONS OF THE WALLS OF THESEDISAPPEAR FORMING 3 SEMICIRCULAR CANALS1—POSTERIOR2—SUPERIOR/ANTERIOR3—LATERAL/HORIZONTAL
    • DEVELOPMENT OF INTERNAL EARSEMICIRCULAR CANALS[CONTD]ONE END OF EACH CANAL DILATES TO FORMCRUS AMPULLARESIMPULSE GENERATED IN SENSORY CLLS OFCRISTAE AND MACULAE AS A RESULT OFCHANGE IN POSITON ARE TRANSMITTED BYVESTIBULAR FIBRES
    • DEVELOPMENT OF INTERNAL EARMACULAE ARE SENSORY AREAS IN THE WALLSOF UTRICLE AND SACCULECELLS IN THE AMPULLAE FORM A CREST----CRISTA AMPULLARIS CONTAINING SENSORYCELLS FOR THE MAINTENANCE OF EQUILIBRIUM
    • DEVELOPMENT OF MIDDLE EARTYMPANIC CAVITY AND AUDITORY TUBE• TYMPANIC CAVITY DERIVED FROM THE ENDODERM OF 1st PHARYNGEAL POUCH• POUCH EXPANDS LATERALLY• COMES INTO CONTACT WITH 1st PHARYNGEAL CLEFT• DISTAL PART FORMS TUBOTYMPANIC RECESS• WIDENS AND FORMS THE TYMPANIC CAVITY• PROXIMAL PART REMAINS NARROW AND FORMS THE AUDITORY TUBE THROUGH WHICH TYMP CAVITY COMMUNICATES WITH THE NASOPHARYNX
    • DEVELOPMENT OF MIDDLE EAROSSICLESMALLEUS AND INCUS FROM THE CARTILAGE OF1st ARCHSTAPES FROM THE CARTILAGE OF 2nd ARCHREMAIN EMBEDDED IN THE SURROUNDINGMESENCHYME TILL THE 8th MONTHOSSICLES ARE FREE WHEN THE MESENCHYMEDISSOLVES
    • DEVELOPMENT OF MIDDLE EAROSSICLES [CONTD ]WHEN FREE BECOME SURROUNDED BY THEENDODERMAL EPITHELIUM OF TYMPANICCAVITYEPITHELIUM CONNECTS THEM TO THE WALL OFTHE CAVITYSUPPORTING LIGAMENTS DEVELOP LATER
    • DEVELOPMENT OF MIDDLE EARMASTOID PROCESSDURING LATE FOETAL LIFE TYMP CAVITYEXPANDS TO FORM MASTOID ANTRUMLOCATED IN THE PETROMASTOID PART OFTEMPORAL BONEAFTER BIRTH EPITHELIUM OF TYMPANIC CAVITYINVADES THE DEVELOPING MASTOID PROCESSLATER EPITHELIUM LINED SACS ARE FORMEDMIDDLE EAR CONTINUES TO GROW THROUGHPUBERTY
    • DEVELOPMENT OF EXTERNAL EAREXTERNAL AUDITORY MEATUS• FROM THE DORSAL PART OF 1st PHARYNGEAL GROOVE• ECTODERMAL CELLS AT THE BOTTOM OF THIS FUNNEL SHAPED TUBE PROLIFERATE TO FORM MEATAL PLUG• IN LATE FOETAL PERIOD CENTRAL CELLS DEGENERATE• MEATUS RELATIVELY SHORT AT BIRTH• ATTAINS ADULT LENGTH AROUND 9th YEAR
    • DEVELOPMENT OF EXTERNAL EARTYMPANIC MEMBRANESOURCES1st PHARYNGEAL MEMBRANEEXTERNAL COVERING FROM SURFACEECTODERMINTERNAL COVERING FROM ENDODERM OFTUBOTYMPANIC RECESSMESODERM OF Ist &2nd ARCH GROWS B/W THETWO LAYERS AND FORMS THE FIBROUS STRATUMMAJOR PART OF THE MEMB FIRMLY ATTACHED TO THE HANDLE OF MALLEUS
    • DEVELOPMENT OF EXTERNAL EARAURICLESOURCESIX MESENCHYMAL SWELLINGS ----AURICULAR HILLOCKSARISE ALONG THE MARGIN OF 1st GROOVEFUSE AND FORM THE DEFINITIVE AURICLE
    • CONGENITAL ANOMALIES OF EAR1---CONGENITAL DEAFNESS--- a—CONDUCTIVE b---NERVECAUSES1--MOSTLY GENETIC FACTORS2--MAY BE ASSOCIATED WITH OTHER HEAD ANDNECK ABNORMALITIES3 1st ARCH SYNDROME—INCUS &MALLEUS INVOLVED
    • CONGENITAL ANOMALIES OF EARCONGENITAL DEAFNESS [CONTD ]4--RUBELLA DURING 7th & 8th WEEK MAY CAUSEMALDEVELOPMENT OF SPIRAL ORGAN5--MATERNAL GOITER6--CONGENITAL FIXATION OF THE STAPES
    • CONGENITAL ANOMALIES OF EARAURICILAR ABNORMALITIES [ COSMETIC ]1—PREAURICULAR SINUS—PIT LIKE CUTANEOUS DEPRESSION—TRIANGULAR AREA ANTERIOR TO THE AURICLE CAUSE? ABNORMAL DEVELOPMENT OF HILLOCKS FAMILIAL AND OFTEN BILATERAL
    • CONGENITAL ANOMALIES OF EAR2—AURICULAR APPENDAGES CAUSE—DUE TO FORMATION OF ACCESSORY HILLOCKS USUALLY ANTERIOR TO AURICLE MORE OFTEN UNILATERAL
    • CONGENITAL ANOMALIES OF EAR3—ANOTIA ABSENCE OF AURICLE COMMONLY ASSOCIATED WITH 1st ARCH SYN4—MICROTIA SMALL AURICLE5—ATRESIA OF EXT ACCOUSTIC MEATUS FAILURE OF MEATAL PLUG TO CANALIZE
    • CONGENITAL ANOMALIES OF EAR6—CONGENITAL CHOLESTEATOMA REST OF EPITHELIAL CELLS APPEAR AS WHITE CYST LIKE STRUCTURES MEDIAL TO OR WITHIN THE TYMPANIC MEMBRANE ORIGIN FROM MEATAL PLUGREST---GROUP OF CELLS THAT HAVE BECOMEDISPLACED AND LIES IN TISSUE OF ANOTHERCHARACTER