医学专业英语汇报PPT,骨骼系统

BobZhengWuhanUniversityBonereplacementisthereplacementofoldbonetissuebynewbonetissueNevermetabolicallyatrestReplacingitselfthroughoutadultlifeRemodelingallowswornorinjuredbonetoberemovedandreplacedwithnewtissueRemodelingallowsbonetoserveasthebody’sstorageareaforcalciumConstantsupplyofCa2+inthebloodstreamneededfor:◦Transmissionofnerveimpulses◦Musclecontraction◦Bloodcoagulation◦CelldivisionOsteoclastandosteoblastSufficientquantitiesofcalcium(Ca)andphosphorus(P)Sufficientamountsofvitamins,particularlyvitaminDProperamountsofthehormonesGrowthhormone(GH),Calcitonin(CT),Parathormone(PTH),SexhormonesSecretedbythepituitarygland,responsibleforgeneralgrowthofbonesToomuchGigantismToolittleDwarfismCTisproducedbythethyroidgland,inhibitsosteoclasticactivityPTHissecretedbytheparathyroidglands,increasesthenumberandactivityofosteoclastsAntagonisticCTPTHControlofBoneDepositionControlofBoneResorption[Ca2+]controlledbynegativefeedbackloopPromotethegrowthofnewboneBringaboutthedegenerationofcartilagecellsAgingforskeletalsyetemhappenswhenOsteoblastactivitydeclines,whileosteoclastactivityremainslevelLossofcalciumfrombonesForfemale,thislossbeginsafterage40butformale,thislosstypicallydoesnotbeginuntilafter60MENOPAUSE!Remember,estrogen(sexhormoneforfemale)stimulatesosteoblastactivityandsynthesisofbonematrixMencontinuetoproduceandrogens(sexhormoneformale)intolatelifeandthusarenotasaffected.AnothereffectforagingisthedecreaseintherateofproteinformationLessorganicmatrixmoreinorganicmatrixBonesbecomebrittleandeasytofractureWhenthelossofbonemasscompromisesnormalfunctionapersonisdiagnosedwithosteoporosis.PrematuremenopauseBodybuild–shortwomenhavelessbonemasstobeginwithWeight–thinneratgreaterriskSmoking–decreasesestrogenlevelsLackofdietarycalciumSedentarylifestyle–decreaserateofabsorptionDrugs–alcohol,cortisone,tetracyclineNulliparity(neverhadchildren)AncestryorFamilyhistoryNosmokingTakeinmorecalciumDon’tsitallthedayBecarefulwhentakingdrugs