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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.

SmoothMuscle

Sources

• Fried,GeorgeandHademenos,George.Schaum’sOutlinetoBiology.NewYork:McGraw‐Hill,2009

• www.google.com/images