Chapter 37

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Chapter 37Protection, Support, MovementIntegumentProtectionPhysicalDehydrationBody temperature regulationCutaneous sensationMetabolic functionsBlood reservoirExcretion of wastesRespiration (amphibians)

IntegumentCuticleHardened outer coveringExoskeletonRoundworms, most arthropodsProtein or chitin

IntegumentSkinSofter, ketatin-containing outer coveringAssociated tissues (scales, hair, feathers, beaks, horns, nails, etc.)Vertebrates

IntegumentEpidermisStratified squamous epitheliumKeratinocytes Keratinwater-proofing proteinMelanocytesMelaninpigment & sunscreen

IntegumentDermisMostly dense irregular connective tissueCushion body against stretch & stressBlood, lymph, nervous tissueHypodermisMostly adipose tissue

IntegumentSweat glandsTrue sweatEccrineApocrineCeruminous (ears)Mammary

Sebaceous glands

IntegumentChromatophoresSkin & eye color in ectothermsMelanocytes in birds & mammalsColor changePigment translocationCephalopodsmuscles surround elastic cell, change its shape

SkeletonHydrostatic skeletonCnidarians, platyhelminthes, annelids, nematodesFluid cavity surrounded by musclesChange shape for support & movmentExoskeletonMollusks, arthropodsCalcium carbonate or chitinLimits growth, but more strength, site for musclesEndoskeletonEchinoderms, vertebratesSupports greater weightDoesnt limit growthSkeletonEcdysisMoulting of exoskeletonContinuous growth of arthropods not possibleMust periodically shed exoskeleton & allow rapid growthSteps:Cuticle separates from epidermisNew cuticle secreted by epidermisOld cuticle shedAnimal inflates body w/ air or water to expand new cuticleNew cuticle dehydrates & hardensAnimal vulnerable during this timeSoft shelled crabs

SkeletonBone functionsSupportProtectionMovementStorageHematopoiesisBlood cell production

SkeletonShapeLongShortFlatIrregularLocationAxialAppendicularSkeletonCompact boneSpongy boneHyaline cartilagePeriosteumYellow marrowfat storageRed marrowblood cell productionLigamentsbone to boneTendonsmuscle to bone

SkeletonOsteocytesOsteoblastsOsteoclastsHaversian (central) canal

Bones to know.MandibleMaxillaZygomatic

SternumRibScapulaClavicle

Bones to knowHumerusUlnaRadiusCarpals

FemurPatellaTibiaFibulaTarsals

Bone DisordersOsteomalacia (adults), Rickets (children)Vitamin D deficiencyReduction in calcium in bonesSoft bone, easily bent or brokenOsteoporosisOsteoclast activity outpaces osteoblastsHormonal influencesNutritional influences Brittle, weak bonesJointsFibrousImmovibleSkull sutures, teethCartilaginousSlightly moveableVertebrae, pelvisSynovialFreely moveableFluid-filled cavityKnee, elbow, fingers

Joint DisordersSprain/strainStretch or tear of ligaments & tendonsAnterior cruciate ligamentOsteoarthritisWear & tear on jointsUsually w/ old ageRheumatoid arthritisDegeneration of jointsAutoimmune disease

MuscleSkeletalCardiacSmooth

MuscleSkeletal MuscleFascicleMuscle fiber (cell)

MuscleSkeletal SarcolemmaMyofibrils

MuscleSkeletal SarcomereActive unitThin (actin) filamentThick (myosin) filamentNeuromuscular JunctionNerve impulse reaches axon termialChannels open in axon, calcium moves into axon terminalVesicles move to surface of axonVesicles open, releasing acetylecholine (ACh)ACh travels across synaptic cleftACh binds to receptors on muscleContraction stimulated

MuscleSliding Filament ModelAnimation

MuscleCardiac Cardiac muscle stimulated by pacemakers in heartMost muscle not directly innervatedIntercalated discs connect cells, continuing muscle impulse

MuscleSmooth

Muscle DisordersMyasthenia gravisShortage of ACh receptorsMuscular DystrophyFragile, abnormal sarcolemmaToo much calcium, damages fibersLoss of regeneration, muscles wasteTetanusClostridium tetani, no release of ACh