POST‐LABORATORYDISCUSSIONforEXAMINATION2

MarilenM.ParungaoBiology22

(specialthankstoMissJillianSiaandGoogleImagesforsomeofthephotos)

DISCUSSIONOUTLINE•  IntegumentarySystem•  ExternalAnatomyoftheFrog

•  SkeletalSystem

• MuscularSystem

•  NervousSystem

•  TobeReported– MusclePhysiology– NervousResponses

THEINTEGUMENTARYSYSTEM

MainFunc<on:servesasaprotec<vebarrieragainstoutside

elements

INTEGUMENTARYSYSTEMSOFINVERTEBRATES

THEINTEGUMENTARYSYSTEM:VERTEBRATES

•  Outerepidermis+Innerdermis(corium)dividedintostrataorlayers

•  FROG:– Epidermis(stratumcorneum)followedbystratumgerminaIvum

– Dermis(Upperstratumlaxumorspongiasumandstratumcompactum=conInuouswithlooselyarrangedsubcutaneousconnecIveIssue)

•  Humans:epidermis=morelayersversusfrog

AMOEBA&PARAMECIUM

AMOEBA&PARAMECIUM

1.  RigidityofMembrane?Amoebalessrigid

2.  Pellicle: provides and maintains shape;preventsexcessiveflowsinofwater

3.  Cilia:surfaceofepithelium

4.  FuncXon::forlocomoXon,feeding,defense,preycapture

GRANTIA

pinacodermpinacocytes

A.  RadialcanalopenstoinsideB.  IncurrentcanalopenstooutsideC.  OsXumistheopeningofanincurrent

canal

TakeNote:simplesquamouswithchoanocytes

TERMS…

•  Pellicle:thinlayersupporIngthecellmembraneinvariousprotozoa,protecIngthemandallowingthemtoretaintheirshape

•  Pinacoderm:asinglecelllayerfoundonthebodysurfaceandliningthecanals(pinacocytesformthepinacoderm;theyareflaRenedcellscontainingmanygranules;capableofcontracIng)

HYDRA

mesoglea

gastrovascularcavity

Takenote:simplecuboidalcellswithnematocysts!!!

TERMS…

•  Nematocysts,CnidoblastorCnidocytes:avenomouscell,providesameansforthemtocatchpreyanddefendthemselvesfrompredators(e.g.jellyfishsIng)

•  Rhabdites:rodlikestructuresinthecellsoftheepidermisorunderlyingparenchymaincertainturbellariansdischargedinmucoussecreIonsactasadefensivemechanism,they'lldissolveinwater,andtheyaredistastefultomostanimalwhowouldpreyonrhabdiIa

DUGESIA:CILIATEDVENTRALEPIDERMIS

TakeNote:simplecuboidalcells,ventrally‐ciliatedwithrhabdites

DUGESIA(Planarian)

1. Buccal cavity ; 2. Gastrodermis; 3. Gastrovascular cavity; 4. Epidermis; 5. Pharynx; 6. Parenchyma

On the outside ofthe flatworm is aciliated epidermisthatcontainsmanygland cells as wellas dark‐stainingrod‐shaped bodiescalled rhabditesthat can dischargetheir contents toform a protecIvem u c o u s l a y e raroundthebody.

FASCIOLA(Flukes)syncytialtegument

parenchyma

TERMS…

•  Syncy<um:alargecell‐likestructurefilledwithcytoplasmcontainingmanynuclei;arespecializedformsusedbyvariousorganismsinnormalIssue;occursmostsimplywhenacelldivideswithoutundergoingcytokinesis

Takenote:collagenfibersandlipid=non‐cellularcuXcleornon‐chiXnizedEARTHWORM

ASCARIS

Cross‐secXonofanadultfemaleA.lumbricoides,stainedwithhematoxylinandeosin(H&E).Notethepresenceoftheprominentmusclecells(MU),graviduterus(UT),intes<ne(IN)andcoiledovary(OV).

Cross‐sec<onofthecu<cleofanadultA.lumbricoides,stainedwithH&E.Shownherearethecu<cle(CU),andimmediatelybelowthecu<cle,thethinhypodermis(HY).Alsoshownaretheprominentmusclecells(MU)andoneofthelateralchords(LC).

COCKROACHCUTICLE:CHITINIZEDDEVELOPINGINTOACARAPACE

TakeNote:ChiXn=polysaccharideandcalciumchloride

STARFISHARM(echinoderms)=EPIDERMIS+DERMISWITHOSSICLES

1. Coelom; 2. Dermal ossicle; 3. Dermal branchiae; 4. Pyloric ceca; 5. Spine; 6. Radial canal; 7. Pedicellariae; 8. Radial nerve; 9. Tube foot; 10. Sucker

TakeNote:ossicles,spiculesandgranules=calciumcarbonate=hard!

FROGSKIN

Mucusgland=cuboidalepithelialcells

Poisonglands=simplesquamoustocolumnar

GLANDSOFTHEFROGSKINCRITERIA MUCUSGLAND POISONGLAND

Epitheliallining SimpleCuboidal Squamous

Size Small Big

DistribuIoninFrog Many Centralized(Few)

LayerOrigin StratumgerminaIvum(Epidermis)

Stratumspongiusom(Dermis)

Layertowhichitextends

Mid‐spongiosum EnIrespongiosum

FuncIon ReducewaterlossandprotecIonfromdessicaIon

Defense

HUMANSCALP

•  Notetheproximityofsebaceousglandstohairfollicles

•  SweatglandsandtheirductsarescaReredintheconnecIveIssuestroma

MEDULLA

CORTEX

HUMANBROWNSKIN

FROGINTEGUMENT•  Epidermis:aboutacellortwothick

•  Dermis:threeorfourcellsthick

•  Thedarkpurplestructuresarenuclei

•  Thestructuretotherightinthephotoisamucusgland

HUMANINTEGUMENT

•  Notetheseverallayerspeelingfromthesurface

•  TheouterporXonofhumanskiniscomposedofflagenedcellsthatmakearatherwaterimperviousbarrier

Outerlayer–deadcells

epidermis

dermis

EXTERNALANATOMYOFTHEFROG

WHYCHOOSETHEMASANIMAL

MODELS?

•  TheyshowbothprimiIveandadvancedvertebratestructures(e.g.fish‐likeandmammal‐likefeatures)

•  PosiIonofinternalorganssimilartohumans

•  Readilyavailable,smallandeasytostudy

FROGVERSUSTOAD

3ESSENTIALSENSEORGANSOFFROGS

•  EXTERNALNARES/NOSTRILS

•  EYES– ProtectedbynicItaIngmembrane/lowereyelid

•  EARS– Tympanun/tympanicmembrane=eardrum

– Representsouterearofthefrog

THEFROG’SAPPENDICULARREGION

MALEVERSUSFEMALEFROG

TAKENOTE:

1.  Overallsizeoforganism

2.  Tympanunsize

3.  PigmentaXon

THESKELETALSYSTEM

FUNCTION:SUPPORTIVESYSTEMS/PROTECTION

HYDROSTATICSKELETONS

•  HavenofirmbaseaRachments

•  DevelopmuscularforcebycontracIngagainstthecoelomicfluid

•  Example:annelids,cnidarians

RIGID/MINERALSKELETONS

•  Consistofmineralelementsmadeofsolidcrystalsofslatsincorporatedwithsomeorganiccompounds

•  Types–  Exoskeleton:arthropodsand

mollusks

–  Endoskeleton:vertebrates•  SomaIcandvisceral

•  Dermalandreplacement

TYPEANDCHEMICALCOMPOSITIONOFEXOSKELETONS

ORAGNISMS TYPE COMPOSITION

Radiolarians Shellwithtesta StronIumsulfate,silicaandcalciumcarbonate

Arthropods ChiInizedcuIcle/carapace

MineralizedchiIn

Mollusks shell Canchiolinwithcalciumcarbonate

Echinoderms ossicles calciumcarbonate

Turtles Carapaceandplastron/scutes

calciumcarbonate/keraIn

TYPEANDCOMPOSITIONOFENDOSKELETONS

ORGANISMS TYPE COMPOSITION

Sponges Spiculesspongia Silica/sponginfiber/Calciumcarbonate

Corals Spicules Calciumcarbonate

Vertebrates Bone Calcium/Magnesiumphosphate,collagenandglycosaminoglycans

TAKENOTE:THESKULL•  Convexdorsally,concaveventrally•  Enclosesthebrain&lodgesthesenseorgans

•  Parasphenoid–unpairedbone

•  Dermalbones–bonesformedfromintramembranousossificaIon– FromdirectmineralizaIonoftheembryonicconnecIveIssuematrix

•  CarIlagebones–bonesformedfromendochondralossificaIon– RequiresacarIlagetemplateormodel

VISCERALSKELETON

•  Derivedfromgillarches

•  Upperandlowerjaws

•  Hyoidapparatus

•  CarIlagesthatsupportthelarynxorvoicebox

VERTEBRALCOLUMN

• Mainaxialendoskeletalsupportofthebody

•  Encloseandprotectthespinalcord

•  10separateseriesofbonesconnectedbyligamentsandarIculatedbyzygapophyses– Typicalvertebra(2ndto8th)– Atypicalvertebra(1,9and10)

PECTORALGIRDLE•  Clavicle–onlymembranebone

•  Glenoidfossa–holdstheheadofthehumerusinaball‐and‐socketjoint

•  Acetabulum–holdstheheadofthefemurinaball‐and‐socketjoint

•  Deltoidcrest–muscleaRachmenttofacilitateeasiermovement

•  CarIlage(attheendoflimbs)–  ReducefricIonofbonetobonecontact– MakesconnecIonsmooth

•  SKULL,PECTORALGIRDLE,STERNUMCENTRUM(vertebralcolumn)

–  ProtectstheverysensiIveandessenIalorgansofthebody

WHATAREJOINTS

•  juncIonoftwobonesthatpermitsmovement

•  TYPES:–  Ribsandvertebrae=semi‐mobilejoints:ribs:bonesofthethoracic

cage.Vertebra:eachofthebonesofthespinalcolumn.Semi‐mobilejoints:veryrestrictedflexibility.

–  Vertebrae=carXlaginousjoints:vertebra:eachofthebonesofthespinalcolumn.CarIlaginousjoints:flexibilityduetocarIlage,anelasIcIssue.

–  Skull=immovablejoints:skull:bonycaseofthebrain.Fixedjoints:jointsthatdonotallowflexibility.

–  Elbow=hingedjoint:elbow:jointconnecIngtheforearmtotheupperarm.Hingedjoint:flexibleinonlyonedirecIon.

–  Hip=ballandsocketjoint:hip:partonthesideofthebody,betweenthewaistandthetopofthethigh.Ballandsocketjoint:flexibilityduetoadomedbonethatturnsinacavityofthesameshape.

THEMUSCLESYSTEM

TAKENOTE:MUSCLESYSTEM

•  ORIGIN– MorefixedormoreproximalaRachment

•  INSERTION– MoremovableormoredistalaRachment

•  ACTION– Accomplishedbycontrac<onorshorteninginlength

VENTRALMUSCLESOFTHEFROGTHIGH

•  1.Sartorius •  2.Adductorlongus •  3.Adductormagnus •  4.Gracilismajor •  5.Gracilisminor •  6.Semitendinosus

DORSALMUSCLESOFTHETHIGH

•  1.Gluteus

•  2.Piriformis

•  3.Tricepsfemoris •  4.Semimembranosus

•  5.Bicepsfemoris

MUSCLESOFTHESHANK

•  1.Gastrocnemius •  2.TibialisposXcus •  3.Extensorcruris •  4.TibialisanXcuslongus

•  5.Tibiofibulabone

PERONEUS

MUSCLESOFHEAD

•  4.masseter

•  5.depressormandibularis

•  6.dorsalisscapulae

•  10.laXssimusdorsi

MUSCLESOFTHEHEAD

•  2.pterygoideus •  4.masseter

•  5.depressormandibularis

•  6.dorsalisscapulae •  7.deltoid •  10.laXssimusdorsi

•  7.deltoid•  9.pectoralis •  13.lineaalba •  20.tricepsfemoris

•  21.adductormagnus •  22.sartorius•  24.gracilismajor

•  25.gracilisminor •  26.gastrocnemius •  27.tendonAchilles•  30.mylohyoid

•  2.pterygoideus •  3.temporal •  4.masseter •  5.depressor

mandibularis •  6.dorsalisscapulae •  10.laXssimusdorsi •  11.longissimusdorsi•  17.gluteus •  18.piriformis •  20.tricepsfemoris •  25.gracilisminor•  26.gastrocnemius •  28.Semimembranosus •  29.bicepsfemoris

THENERVOUSSYSTEM

FROGBRAIN(VENTRAL)

•  1.Olfactorynerves

•  2.OpXcnerves •  3.Olfactorylobes •  4.OpXctracks

•  5.Cerebralhemispheres •  6.Pituitarygland •  7.Medullaoblongata

FROGBRAIN(DORSAL)

•  1.Olfactorylobes

•  2.Cerebralhemisphere •  3.OpXclobes •  4.Cerebellum

•  5.Medullaoblongata •  6.Choroidplexus

FROG’SCRANIALNERVESNUMBER NAME NATURE FUNCTION

I olfactory sensory smell

II opIc sensory vision

III osculomotor motor Movementofeyemuscles

IV trochlear motor Movementofeyemuscles

V trigeminal Motor/sensory MusclesofmasIcaIon;conveyssensaIon

VI abduceus motor Movementofeyemuscles

VII facial Motor/sensory Movementoffacialmuscles;chewing;movementofneck

VIII auditory sensory Hearingandsenseofequilibrium

IX glossopharyngeal Motor/sensory Tasteandtouch;movementinthephranyx

X vagus Motor/sensory Sensory:vocalchords;lungs,motorpharnyx

FROG’SSPINALNERVES

FROG’SSPINALNERVESNUMBER FUNCTION

IFormsbranchialplexusthatcontrolsmotorreflexofupperbody

II

III

IVSupplythemusculatureandtheskinofabdomenV

VI

VIIUnitetoformthesciaIcplexuswhichresultsinthesciaIcnervetothehindleg

VIII

IX

X Suppliesthecloaca,urinarybladderandoviducts

SPINALCORD

STRUCTURALDIFFERENCE:WHITEANDGRAYMATTER

•  ThewhitemaRergetsitsnamefromthewhiIshmyelinthatcoverstheaxons

•  ThegraymaRerconsistofcellbodiesanddendritesandisconcernedmainlywithreflexconnecIonsatvariouslevelsofthespinalcord

PLEXUS:NerveFibers

•  BRACHIAL– anarrangementofnervefibersrunningfromthespinethroughtheneck,theaxilla(armpitregion),andintothearm

– allnervesofthearmstemfromthebrachialplexus–  lesionsoftheplexuscanleadtoseverefuncIonalimpairment

•  SCIATIC/SACRAL– anerveplexusthatliesagainsttheposteriorandlateralwallsofthepelvis,isformedbytheunionofthelumbo‐sacraltrunkandthefirst,second,andthirdsacralnerves,andconInuesintothethighasthesciaIcnerve

– PAINorsciaIc

THECSFFUNCTIONS:ACUSHIONBETWEENPIAANDDURAMATER

•  Buoyancy=allowsthebraintomaintainitsdensitywithoutbeingimpairedbyitsownweight,whichwouldcutoffbloodsupplyandkillneuronsinthelowersecIonswithoutCSF.

•  ProtecIon=protectsthebrainIssuefrominjurywhenjoltedorhitcausinghemorrhaging,braindamage,andsomeImesdeath.

•  ChemicalStability=rinsingthemetabolicwastefromthecentralnervoussystemallowsforhomeostaIcregulaIonofthedistribuIonofneuroendocrinefactors,towhichslightchangescancauseproblemsordamagetothenervoussystem

•  PrevenIonofbrainischemia=bydecreasingtheamountofCSFinthelimitedspaceinsidetheskullfacilitatesbloodperfusion.

Ok…readyfortheEXAM???