the musculoskeletal system - california state university ...psmith3/teaching/marzi.pdf · the...
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TheMusculoskeletalSystem:SupportandMovement
ChrisMarzi
SeniorSeminar
Dr.PaulSmith
Introduc>on
• InvertebrateSupportSystems
– Hydrosta>cSkeletons
– Exoskeletons
• TheVertebrateEndoskeleton
– SkeletalDevelopment
– TheSkeletalSystemandHomeostasis
– Movement
• AnatomyandPhysiologyofVertebrateMuscle
– SkeletalMuscle
– CardiacMuscle
– SmoothMuscle
TheMusculoskeletalSystem
• Themusculoskeletalistheinterac>onofmusclesandtendonsandligamentsandbonesandjointsandassociated>ssuesthatmovethebodyandmaintainitsformandallowthebodytofunc>on.
• Alsocalledthe“locomoter”system.
InvertebrateSupportSystems
Hydrosta)cSkeletons Exoskeletons
Hydrosta>cSkeletons
Descrip)on
• Earlyinvertebratesreliedonthemanipula>onoffluidsformovement.
• Limitsinstructuralability
• Usuallyonlyfoundinorganismsthatresideinaqua>corloosesoilenvironments.
Earthworm
Hydrosta>cSkeletons
• Watercavitythatallowsmovementismanipulatedbymuscleswithintheorganisms.
• Organismstendtobefragile.
• Duetostructure,limitedmobility.
• Segmenta>onallowsforbeRermovement.
Exoskeletons
Descrip)on
• Foundprimarilyininsects.
• Protectswellagainstwaterlosstotheenvironment.
• Musclearrangementdiffersfromthestructureofvertebrates.
• Excellentatterrestrialadapta>ons.
CarpenterAnt
TheVertebrateEndoskeleton
Descrip)on
• Composedofanetworkofboneandcar>lage.
• Rigidwiththeexcep>onofjointsthatallowmobilityintheskeletalframework.
• 206bonesinthehumanbody.
HumanSkeleton
TheVertebrateEndoskeleton
SkeletalDevelopment
• Theskeletonarisesfrommesoderm.
• Earlyforma>onofsomites.
• Forma>onofthenotochord.
• Developmentofthespinalcolumn.
• Mesodermalcellmigra>on.
• Limbbudsproducetheappendicularskeleton.
SkeletalDevelopment
TheSkeletalSystemandHomeostasis
• Servesmaintainbalanceinthreeways.First:Behavioralresponsestoenvironmentalchange.
Second:Redbloodcells,oratleastpartsthatmakeupredbloodcellsareproducedinthebonemarrow.
Third:Theskeletalsystemstoresmineralsthatareabletobereleasedasneeded.
Movement
• Theaxialpor>onoftheskeletalsystemisusedtoprovidestabilitytovitalorganswhiletheappendicularprovidestheactualmo>on.
• Appendicularsystemisconnectedbyligamentsatthejoints.
• Tendonsconnecttheskeletalsystemtothemuscularsystem.
• OriginandInser>on.• FlexionandExtension.
VariousMusclesoftheHumanBody
AnatomyandPhysiologyofVertebrateMuscle
• Theabilityforinternalmovementaswellasexternalmovementisvitaltoallanimals.
• Everyanimalhasacertainsystemofmovement.
• InternalsystemforAmoebaisthroughuseofpseudopodia.
Primi>veLocamo>onSystems
Cilia Flagella
SkeletalMuscle
• ARachedtotheskeletalsystem.
• Areabletobemovedbyvoluntarycontrol.
• Striatedmuscle.
• Thisgroupusuallymakesupthelargestmuscletypeinanorganism.
Organiza>onofSkeletalMuscle
TheMuscleFiber
• Basicunitforskeletalmuscle.
• Mul>pleNucleus.
• Thestria>onseeniscausedbymyrofibrils.
• Singlesegmentofamyrofibriliscalledasacromere.
• MovementismediatedbyATP
TheMuscleFiber
• SarcomereissurroundedbyaZ‐line.
• Ac>nandMyosininteractinanygivensarcomere.Thiscausesthemuscletocontract.
• Ca2+Ionsreleasedduringcontrac>on.
SarcomereStructure
CardiacMuscle
• Striated,mononucleatecells.
• Formnetworks.
• Cellsareconnectedbyanintercalateddisk.
• Resemblesanervoussystemtypeconnec>on.
• Structuredtoallowindependentbea>ngofexternalnervouss>mula>on.
• Ac>onpoten>almuchhigherthanskeletalmuscle.
CardiacMuscle
SmoothMuscle
• Mononucleateandmuchsmallerthanskeletalmusclefibers.
• Commonlyexistin>ghtlypackedareas.
• Possesnon‐nueralcoordina>on.
• MoreAc>nandlessMyosin.
• Capableofmaintaininglongperiodsofcontrac>on.