NURSINGTheory

VocationalEducationHIGHERSECONDARYFIRSTYEAR

APublicationunderGovernmentofTamilnadu

DistributionofFreeTextbookProgramme(Notforsale)

UntouchabilityisasinUntouchabilityisacrimeUntouchabilityisinhuman

CollegeRoad,Chennai600006.

GovernmentofTamilnaduFirstEdition2010

CHAIR PERSONDr.Mrs.P.MangalaGowri

CollegeofNursingMadrasMedicalCollege

Chennai600003.

Authors

Dr.Mrs.PrasannaBaby Mrs.M.ElizabethCollegeofNursing GovernmentHigherSecondarySchoolChengalpetMedicalCollege Ottanchantram.Chengalpet.

Dr.Mrs.N.Jaya Prof.KamalaSubbaiyanCollegeofNursing VenkateshwaraCollegeofNursingMadrasMedicalCollege Chennai.Chennai600003.

ThisbookhasbeenpreparedbytheDirectorateofSchoolEducationonbehalfoftheGovernmentofTamilnadu

Thisbookhasbeenprintedon60GSMpaper

FOREWORD

ThedevelopmentofthetextbookNursingresultedfromthecombinedeffortsofmanytalentedprofessional,committedtoexcellence.SpecialrecognitionanddueacknowledgementisherebymadetotheDirectorofSchoolEducationandtheJointDirectorofSchoolEducationChennai.

Nursingisamajorcomponentofthehealthcaredeveliverysystemandnursesmakeupthelargestemploymentgroupwithinthesystem.

Nursingservicesarenecessaryforeverypatientseekingcareofvarioustypesincludingprimary,secondary,tertiaryandrestorative.Asnursingisanimportantpartofhealthcaredeliverysystem,thenursesneedtohaveasoundknowledgeaboutnursingasaprofessionandcommonprofessionalactivities.

WiththepresentintroductionofVocationalcoursessuchasnursingintheacademicstreamasoneoftheoptions,itisbelievedthatitwillcontributetowardsthebasicnursingcareofindividuals,familiesandcommunityforhealthandhappiness.ItwillalsobeafoundationcourseforfuturediplomaanddegreeprogrammesinNursing.

InthiseditionanewchapteronBioMedicalWasteManagementhavebeenaddedinviewofthefactthattheseknowledgewillbeessentialforthestudentstolearnbeforeenteringintotheprofessionalcourse.Thesubjectcontentshasbeendeveloped,refinedandreconstructedatseveralpointsasperthecurrentperspectives.

Dr.Mrs.P.MangalaGowri.

III

CONTENTS

S.No Subject PeriodsPageNo.

1. NurseandNursingasaprofession 20Definitionofhealth. 1Conceptofhealth. 1Health&illnesscontinuum. 1HistoryofNursing 2DefinitionofNursing&Nurse. 9QualitiesofNurse. 9FunctionsofNurse 10Fundamentalrulesfornursing. 11Codeofethicsinnursing. 11FlorenceNightingalepledge. 13Definitionofhospital. 14TypesofHospitals 14FunctionofHospitals 15

2. AnatomyandPhysiology: 50Definitionofanatomy&physiology 19Anatomicalpositions 19Cells&Tissues 20Musculoskeletalsystem 22Nervoussystem 33CardioVascularsystem 37Blood 38Digestivesystem 40Respiratory system 46Excretory system 49Endocrine system 51Senseorgan 55Reproductive system 61

3. Introduction to Psychology 30Definitionofpsychologyandmentalhealth 73Characteristicsofmentallyhealthyperson 73Importanceofpsychologyinnursing 73Factorsinfluencingmentalhealth 74

IV

S.No Subject PeriodsPageNo.

DefinitionofLearning 74Characteristicsoflearningbyinsight 76Observation,Attention,&Perception 77Emotion 80Personality 83Defencemechanism 87

4. Principlesandpracticeofnursing 60DefinitionofNursingprocess 91StepsinNursingprocess 91Admissionofapatient 92Orientationtotheward 93Careofbelongings 94Dischargeofapatient 94Bed&Bedmaking 94Therapeuticenvironment 96Psychosocialenvironment 96BodyMechanicsandPositioning 96HygienicNeedsPersonalhygiene 98Safety&ComfortNeeds 99Activity&Exercises 100Moving,shifting&liftingpatients 101OxygenNeed 102EliminationNeeds 104

5. HealthAssessment&PhysicalExamination 30DefinitionofphysicalExamination 108PurposesofphysicalExamination 108MethodsofphysicalExamination 108PrinciplesofphysicalExamination 109

- Headtofootexamination 109Physiological assessment 111 - Temperature 111 -Pulse 115 - Respiration 116 - Bloodpressure(BP) 117 - Pain 117Testing&examination 118

V

S.No Subject PeriodsPageNo.

-Urine. 118 -Stool. 121 -Sputum. 122

6. Medical&surgicalAsepsis: 20Definitionofasepsis 126Principlesofasepsis 126Types of asepsis 126Basicprinciplesofsurgicalasepsis 127

- Useofgloves 127 - UseofAprons 127 - UseofMasks 128

Sterilizationanddisinfection 128 - Definition 128 - Methodsofsterilization 128

Handlingofsterilearticles 133BiomedicalWasteManagement 134

- Classificationofwaste 134 - Segregation,PackingandTransporting 135 - Categoriesofbiomedicalwaste 135

7. FirstAid: 60DefinitionofFirstAid 140RulesandprinciplesofFirstAid 140FirstAidandEmergencysituations 140

- FireandBurns 140 - Fractures 142 - Drowning 142 - Haemorrhage 143 - Shock 144 - Bandagingandsplinting 145 - HeatstrokeorSunstroke 147 - Heatexhaustion 147 - Frostbite 149 - BitesandStrings 150 - Poisoning 153 - Foriegnbody 159 - CarAccident 160

VI

S.No Subject PeriodsPageNo.

Cardiopulmonary resuscitation 162Emergencykit 163

8. HospitalHousekeeping 20Principlesofgoodhousekeeping 169Cleanlinessandorderliness 169Careof rubbergoods 170

- Gloves 170 - Rubbertubes 170

Careofenamelwares 171 - Bedpan 171 - Urinal 171 - Kidneytray 171 - Sputumcup 171

Careofinstruments 171 - Sharpinstruments 171 - Glassware 172 - Syringeandneedle 172 - Careoflinen 172

CareofpatientsUnit 173 - Flooring 173 - Wall 174 - Sanitaryannex 174 - Bathroom 174 - Lavetory 174

VII

19

2.ANATOMYANDPHYSIOLOGY

DEFINITIONOFANATOMYANDPHYSIOLOGY

Anatomy: Itisthestudyofthestructureofthehumanbody.

Physiology:Itisthestudyofthe functionsofthehumanbody.

Thebodyasawhole:

Thebodyiswonderfullymade,likeacomplex,perfectmachine.Eachpartisspeciallyconstructedtocarryoutitsownfunction,andtoworkasawholewiththeotherparts.

Lookatapersonstandingwitharmsatthesides,palmsturningforward,thisiscalledtheanatomicalposition.Thebodyisseentoconsistofthehead,neck,trunk,upperlimbs(thearms)andlowerlimbs(thelegs).

ANATOMICALPOSITION

Whenapersonstandinguprightwiththeheadfacingforward,armsbythesidesandthepalmsofthehandsfacingforwardandfeetstogetherissaidtobeanatomicalposition

THEFOLLOWINGTERMSAREUSEDINANATOMY:

1)SUPERIOR higher

2)INFERIOR lower.

3)ANTERIOR nearerthefrontofthebody.

4)POSTERIOR nearerthebackofthebody

5)MEDIAL nearertothemidline.

6)LATERAL totheside.

7)PROXIMAL nearertotheheadorsource.

8)DISTAL distantfromtheheadorsource.

9)EXTERNAL outside,orawayfromthetrunkcentre.

10)INTERNAL inside,ornearertothetrunkcentre.

11)SUPERFICIAL nearerthebodysurface.

12)DEEP inside,awayfromthebodysurface.

Thebodyhasastrongframeworkofbonescalledthe skeleton. Theskeletoniscoveredbymusclesandothersofttissuesandbyskinontheoutside.

Cavitiesofthebodyandtheircontents:

Somebodypartsformspacescalled cavities,inwhichimportantinternalorgansareprotected.

1)The cranialcavityorskull containsthebrain.

20

1

2

34

5

6

2)The thoraciccavityorchest contains:

(a)Thelungs

(b)Theairpassagestracheaandbronchialtubes.

(c)Theesophagusorfoodpipe,whichliesbehindthetrachea.

(d)Theheart.

(e)Thegreatbloodvesselsandthethoracicduct(thelargestlymphaticvessel).

3)The abdominalcavity,whichisseparatedfromthethoraciccavitybyadomeshapedmusclecalledthediaphragm.Itcontains:

(a)Thestomach (b)Thesmallintestines.

(c)Thelargeintestineorbowel (d)Theliver.

(e)Thespleen (f)Thekidneys.

(g) Theureters (i)Thepancreas.

4)The pelviccavity,whichcontains:

(a)Thereproductiveorgans

(b)Thebladderwhenempty(whenfullitrisesintotheabdominalcavity)

(c)Therectum.

CELLSANDTISSUES

Alllivingthings,includingthehumanbody,aremadeupoflivingcells.Thecellisthestructuralandthefunctionalunitofthehumanbody.

Justasmanykindsofmaterialsmaybeusedintheconstructionofalargebuilding,inthesamewaymanydifferentkindsofcellsarefoundinthebody.

StructureofaCell:Acellhasthefollowingparts:

(a)Cellmembrane,theoutercovering.

(b)Protoplasm,themainsubstanceofthecell.

(c)Nucleus,whichcontrolsactivitiesofthecell

1)Vacuole

2)Cytoplasm

3)Nucleus

4)Endoplasmicreticulum

5)Mitochondrion

6)Cellmembrane

Fig.2.1StuctureoftheCell

21

Functionsofcells:Byfunctionswemeantheactivities

(a)Digestion intakeofthenutrients.

(b)Excretion eliminationofwastes.

(c)Respiration takingandusingoxygen,andgivingoutcarbondioxide.

(d)Growthandrepair increasesthesizeofthecellandreplacementofwornoutcell.

(e)Somecellsmoveaboutz,andsomehavespecialfunctions.

(f)Reproductionisbyeachcellsimplydividingintotwo.

TISSUES

Tissuesarematerialsmadeupofgroupsofsimilarcells.Cellsareofvarioustypes,andtissuesvaryaccordingtothetypesofcellsintheirstructure.Therearefourmaintypesoftissueinthehumanbody.

Fig.2.2Variouskindsofcells

1)Epithelialcells(2)Connectivetissue(3)Fattytissue(4)Cartilage

(1) Epithelialwhichformscoveringsliketheskin,liningmembranesandglandsconnective,whichhelpstosupportandbindpartstogether,holdingtheminplace.

(2) Thereareseveraltypesof connectivetissue includingbone,cartilage,ligaments,fattyandelastictissue,alsobloodandlymph(thefluidtissues).

(3) Muscularthistissuehasthepowerofcontraction,whichcausesmovement.

(4) Nervous conductsnerveimpulses.

ORGANSANDSYSTEMS:

Tissuesarejointedinlargerunitscalled organs, suchastheheart,lungs,brain,liver.Eachorganismadeupoftypesoftissue,whichenableittodoitsspecialwork.

Asystem isagroupoforgans,whichtogethercarryoutoneoftheessentialfunctionsofthebody.Thereareninesystemslistedbelow.Allofthesesystemsworkharmoniouslytogetherinahealthybody.

22

S.No.SystemsofthebodyFunctions

1. SkeletalSystem Support,movementandprotection

2. MuscularSystem Movementsandproductionofheat.

3. NervousSystem Controlofbodyactivities.

4. CircularSystem Transportoffoodandoxygen,wasteproducts.etc.

5. RespiratorySystem Takinginofoxygenandgivingoffcarbondioxide.

6. DigestiveSystem Takinginfood,breakingitdownintonutrientsforuse

bybodycells.

7. ExcretorySystem Removalofwastematterfromthebody

8. Endocrine Productionofhormones,whichinfluencetheactivity

ofcells.

9. ReproductiveSystem Enablesnewindividualstobeborn.

(I)MUSCULOSKELETALSYSTEM

Theskeletonisthebonyframeworkofthebody.Thehumanskeletoniswonderfullymadeinsuchaway,thatitcansupportthebodyintheerectpositionandenablethebodytomovefreely.

StructureandFunctionsoftheSkeleton:Theskeletoniscomposedof206separatebones intheadult,andthecartilagesandligaments,whichhelptounitethebonesatthejoints.

ThePartsoftheSkeletonare:

(1) Skull,madeupof29bonesinall(includingmiddleearbonesandthehyoid).

(2) SpineorVertebralcolumnmadeupof26Separatebones.

(3) ThoraxorChestmadeupof25(12pairsofribsandthebreastbone)

(4) Upperlimbs,each32bones.

(5) Lowerlimbs,each31bones.

Thetotalbonesinourbodyis206.

TypesofBones:

(1) Longbones Theseareinthearms,legsandfingers.Theyactasleverstomoveparts.

(2) Shortbones Asinthewristsandankles.

(3) Flatbones Theseincludestheribs,shoulderandbonesofthecranium.

(4) Irregularbones Suchasthebonesofthefaceandofthespine.

23

FunctionsoftheSkeleton:

1) Supportsandgivesshapetothebody. 2) Protectsinternalorgans.

3) Movementswiththehelpofmuscles. 4) Formsbloodcells.

Structureofskeletaltissue:

1) Periostium: Thisistheoutercoveringofbones.Itcarriesbloodvesselsandnerves.

2) CompactBone:Mainlycomposedofcalciumandphosphorus,isthehardouterlayerofbonetissue.

3) Cancellous Bone: insideisaporoustypeofbonewithmanytinyspaces.Ithelpstomaketheboneslight.

(a) RedMarrow:Thisfillsthespacesincalcellousbone.Redbonemarrowproducesredbloodcellsandsomewhitebloodcells.

Fig.2.3LongBone Fig2.4aShortBone

1)HyalineCartilage2)Periosteum3)MedullaryCavity

1)Fibula2)Tibia

1

2

3

Fig2.4bShortBone

1)Phalanges2)MetatarsalBones3)TarsalBones

2

1

3

1

2

24

(b) YellowMarrow:Thisismainlycomposedoffatcells.Yellowbonemarrowfillstheshaftofthelongbonemakingthemlight.

(c) Cartilage:Astrongplaintissuelikehardrubbersisattachedtosomebones.Eg.Theendofthenose,andofitsribs

4)Ligamentsaremadeofstrongfibroustissueandtheyholdbonestogetheratthejoints,allowingsomemovement.

TheSkullconsistsoftwoparts:

1) Thecranium,whichislikeaboxinwhichthebrainiswellprotected.

2) Thebonesoftheface.

Thecraniumismadeupofeightbonesasfollows:

1) Frontalbone:Whichformstheforeheadandhelpstoprotecttheeyes.

2) Parietalbone Oneateachsideofthetopoftheskull,joinedintothemiddle.

3) TemporalbonesOneoneachsidebelowtheparietalbones.Theseprotecttheinnerpartsoftheears.

4) OneOccipitalbone:Thisformsthebackoftheheadandpartofthebaseoftheskull.Ithasalargeopeningforthespinalcordtopassthrough.

5) OneSphenoid Ahatshapedbone,whichalsoformspartofthebaseoftheskull.Ithasalittleseatforthepituitarygland,andsomeholesforbloodvesselsandcranialnervespassthrough.

6) OneEthmoid Whichformstheroofofthenoseandinbetweentheeyes.Ithasmanysmallholesforthenervesofsmalltopassthroughthebrain.

1

2

3

4

5

6

78

910

Fig2.5TheSkull

1)ParietalBone2)TemporalBone3)OccipitalBone4)MaxillaryBone5)MandibleBone6)FrontalBone7)SphenoidBone8)LacrimalBone9)EthmoidBone10)MalarBone

25

TheFacehasthefollowingfourteenbones:

Two nasalbones,whichformthebridgeofthenose.

Two lacrimalbones,neartheeyes,whichcontaintherearducts.

Twocheekbones.

Two upperjawbones,withupperteeth.

Two palatebonewhichjoinwiththeupperjawbonesinformingthehardpalate.

Two curledbone,oneineachsideofwallofthenose.

Two vomerbones,whichrestsonthepalateandhelpstoformthenasalseptum.

One lowerjawbone,whichconsistsofthehorizontalpartonwhicharethelowerteeth,andtwoverticalparts,whichmeetthetemporalbones.Theangleofthejawoneachsideisimportant.AllthebonesoftheskullexceptthelowerjawarejoinedfirmlytogetherbyfixedjointscalledSutures.

Sinuses.Someskullboneshavehollowspacescalledsinuseswhichconnectwiththenoseandarefilledwithair.Sinusesmaketheskulllighter,andhelpinthesoundofthevoice.Sinusitisisinfectioninthesespaces.Themainsinusesarethefrontalonesabovetheeyes,andlargeantrumsinuses,oneineachoftheupperjawbones.

Hyoidbones,thisisahorseshapedlittleboneintheupperpartoftheneck.Thetonguemuscleisattachedtothisbone.

TheVertebralColumn

Spineorbackboneisthecentralpartoftheskeleton.Itsupportstheheadandenclosesthespinalcord.Itconsistsof33irregularbonescalledVertebraebutsomearefusedtogetherandsotheseareactually26separatebonesformingthespine.

ThepartsoftheVertebralColumnareasfollows: Cervicalvertebralcolumn intheneckregion.Thefirsttwo,calledatlasandaxisare

importantfornoddingandturningthehead.

12dorsalor thoracicvertebrae atthebackofthechest.Theribsarejoinedtothesevertebrate.

5 lumbarvertebrae intheassistregion.Thesearebigandstrongforgivingsupport.

5 sacralvertebrae arefusedtogethertoformthesacrum,atriangularshapedbonewithahollowanteriorly.Thesacrumhelpstoformthepelvis.

4smallvertebraeinthetailregionarefusedtoformasmalltriangularbonecalledthecoccyx.Itisattachedtothelowerpartofthesacrum.

IntervertebralDiscs

Betweenthebodiesofthevertebraetherearethickpadsofcartilagecalleddiscs.Theyallowmovementinthespine,andactasshockabsorbers.

Thevertebraearealsojointtogetherbyligamentsandmusclesattachedtothebackandsideprocesses.

26

FUNCTIONSOFTHEVERTEBRALCOLUMN

1) Movement:Forward,backward,fromsidetoside,alsonoddingandturningtheheadarepossiblebecausethespineismadeofnotonebutmanysmallbones,withdiscsofcartilageinbetween.

2) Thespinesupportstheweightofthehead,andoftheabdominalorgans.

3) Protectionforthespinalcord,whichlieswithinthespinalcanal,andprotectionfrominjurybycushioningofthediscs.

4) Balanceintheerectpositionismadepossiblebythecurvesofthespine.

TheThorax:Thethoraxorchestisformedbythe sternum (Breastbone)andcostalcartilagesinfront,theribsatthesides,andthetwelvedorsalvertebralbonesattheback.

Thesternumisaflatbone,shapedlikeadaggerpointingdownwards.Thetipconsistsofacartilageknownasthexiphisternum.Theupperpart,likethehandleisjoinedtothetwocollarbones.Thecostalcartilagesarejoinedtothesidesofthesternumandtothetrueribs.

1

2

3

45

Fig2.6VertebralColumn

1)CervicalRegion2)ThoracicRegion3)LumbarRegion4)SacralRegion5)CoccxygealRegion

Fig2.7TheThorax

1&2)Sternum3)TrueRibs4)FalseRibs5)FloatingRibs6)Xyphisternum7)LumbarVertebrae

27

Theribsaretwelvepairsofthelongcurvedbones.Theuppersevenpairsarecalledtrueribs.Theseareeachattachedtothesternumbyitscostalcartilages.

Thenextfivepairsofribsarecalledfalseribsbecausetheyarejoinedbytheircartilagestothoseoftheribsaboveandnotdirectlytothesternum.Thelasttwopairsarenotconnectedtothesternumatall,andarecalledfloatingribs.

FunctionsoftheThorax:

1) Protectionfortheheart,lungs,liver,stomachandspleen.

2) Supportforthebonesoftheshouldergirdleandforthebreast.

3) Importantinrespiration.

BonesoftheUpperLimbs:

Eachupperlimbconsistsofthirtytwobones. One collarbone:Thesetogetherwiththoseoftheothersideformtheshoulderbone.

Shouldergirdle.

One humerus,theboneoftheupperarm.

One radius,theouterboneoftheforearm.

One ulnar,theinnerboneoftheforearm.

Eight carpalbonesofthewrist.

Fourteenphalangesofthefingers.

1 2

3

12

3 4

5

Fig2.8aHumerus

1)Head2)Neck3)Shaft

Fig2.8bTheUlna&Radius

1)HeadoftheRadius2)NeckoftheRadius3)ShaftoftheRadius4)ShaftofUlna5)HeadofUlna

28

The collarbone (clavicle)oneachsideisalongbonewithtwocurves.Itsinnerendisattachedtothesternum,andouterendwiththeshoulderblade.Thecollarboneiseasilyfeltatthelowerandfrontpartoftheneck.Itkeepstheshoulderbladeinplace.Whenitisbrokentheshoulderdropsforwardanddownwards.

The shoulderblade (scapula)oneachsideisattheupperandouterpartofthebackofthethorax.Itislargeflat,triangularshapedbonewitharidgeorspineattheback.Ittakespartintheshoulderjoint.

The humerus isalongbonewitharoundedheadattheshouldersandabroadlowerendattheelbowjoint.

The radiusandulnarbonesoftheforearmreachfromtheelbowjointtothewrist.

Thewristconsistsofeight carpalbones.Theseshortbonesarearrangedintworows,proximalanddistal,withfourbonesineachrow.

Thepalmconsistsoffivelongbonescalledmetacarpal,whicharticulatewiththedistalrowofcarpalbonesandwiththeproximalrowofphalanges. Thephalangesarelongbones.Thethumbhasonlytwophalangeswhilethefingershavethreeeach.

BonesoftheLowerLimbs:

Eachlowerlimbconsistsofthirtyonebones: Oneinnominate orhipbone, One femur,thethighbone, One patella orkneecap, One tibia One fibula thelowerlegbones One tarsalbones oftheankle Fivemetatarsalbones ofthefoot Fourteenphalanges ofthetoes

1

2

3

Fig2.9TheHand

1)CartalBones2)MetaCartalBone3)Phalanges

29

1)TheInnominateBones:Oneoneachside,joinwiththesacrumtoformthepelvis.Besidesprotectingthepelvicorgans,thepelvissupportstheabdomenandprovidesthedeepsocketsforthehipjoints.

Inthefemale,thetruepelvis(lowerpart)isroundsothatthehead,ofthebabycanpassthroughduringdelivery.Inthemalethetruepelvisislong,narrowandheartshaped.

Theinnominateboneinachildisseparatedintothreebones,whicharefusedtogetherintheadult.Thereforethebonehasthreepartsasfollows:

1) Ilium,theupperflatpart,formsthefalsepelvis.Itsupperridgeiscalledtheiliaccrest.

2) Ischium,theheavylowerpart,whichsupportsthebodywhensitting.

3) Pubis,thefrontpart.Thepubicbonesfromthejointcalledsymphysispubis.

Thefemur(thighbone)isthelongestandstrongestboneinthebody.

Thepatella(kneecap)isasmallboneatthefrontofthekneejoint.

Thetibiaisthelongboneontheinnersideofthelowerleg.

Thefibulaisalongthinboneontheoutersideoftheleg.

Thetarsalbonesoftheankle.Thesearesevenshortbones.Thelargestistheheelbone(calcanium).Theupperbonetakespartintheanklejoint.

Themetatarsalbonesarefivelongbonesinfrontofthefeet.Theysupportthetoes.

Thetoebones(phalanges)arefourteeninnumber.Likethefingerbones,theyaresmalllongbones,twointhebigtoeandthreeineachoftheothertoes.

Joints:Ajoint isthepointatwhichtwoormorebonesmeet.Bonesareheldtogetheratthejointsbyotherconnectivetissuesuchasfibroustissue,cartilage,ligamentsandtendons.Musclesarethemeansbywhichallmovementinthebodytakesplace,includingthemovementsofbonesatsomeofthejoints.

Fig2.10InnominateBone

1)Ilium2)Pubis3)Symphysispubis4)SacroiliacJoint5)Ischium

1

2

3

4

5

30

TypesofJoints:

1))Fibrousjoints inwhichthereisnomovement.Eg.Thesuturesoftheskull.Thebonesarejoinedtogethercloselyasthoughtheywerestitched(sutured)together

2) Cartilaginousjoints inwhichtwobonesarejoinedbyapadoffibrouscartilage,whichallowsslightmovement.Theyarefoundinthevertebralcolumnandpelvis.

3) Synovialjoints whicharefreelymovable,arefoundinthelimbsandjaw.

4) Ballandsocketjoints theroundheadofonebonefitsintothecavityofanotherbone:eg.Shoulderandhipjoints.

5) Hingejoint theonlymovementsareflexionandextension.Eg.Elbow,knee.

6) Glidingjoint thebonesglideononeanotherandallowfairlyfreemovements.Eg.Wristandanklejoint.

7) Pivotjoint turningistheonlymovement.Eg.Themovementbetweentheatlasandaxisforturningthehead.

Muscular system

Thefunctionofamuscleistocontractandtoproductmovement.Amuscle ismadeupofbundlesoffibersheldtogether.Thesearetheredfleshofthebody.Therearethreetypesofmuscles:

1) Voluntarymuscle:Theseareconnectedwiththeskeletalsystem,causingthejointstomove.Theyarecalledvoluntarybecausetheiractioncanbecontrolledbythewill.

2) Involuntarymuscle:Workwithoutconsciouscontrolbytheindividualandarefoundintheinternalorgans.

3) Cardiacmuscle:Aspecialtypefoundonlyintheheart.Thefibersarestripedbutthemuscleisnotundercontrolofthewill.

Fig2.11Joints

1)Femur2)Patella3)Cartilage4)Tibia5)SynovialMembrane6)Fibula

1

2

3

4

5

6

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StructuresandFunctionsofVoluntaryMuscles

Avoluntarymuscleisshapedlikeaspindle,andisenclosedinaprotectivecoatcalledfascia.

Thecentreofthemuscleiscalledthebodyorbelly.thebodyinthickandbecomeshorterandthickerwhenthemusclecontracts.

Inhealththemusclesarealwaysinastateoftheslightconstractions,readyatalltimesforaction.Thisstateofreadinessiscalledmuscletone.

Fucntionsare1)Movement,2)Maintainingposture.3)Producingbodyheat.

MainGroupofmusclesandtheiractions

Manymusclesarearrangedinpairs,andopposeeachotherinaction.Theyareoftengroupedaccordingtofunctionasfollows.

1)Flexorscausebendingofajoint.

2)Extensorsstraightenajoint.

3)Abductorsmovetheboneawayfromthemidline

4)Adductorsmovethebonetowardsthemidline.

5)pronatorsturnthehandpalmdownwards

6)Supinatorsturnthehandpalmupwards.

7)Levatorsraiseapart.

8)Sphinctersreducethesizeofanopening.

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4

56

7

Fig2.12MusclesoftheBody(Anterior)

1)Sternomastoid2)Deltoid3)Pectorails4)Biceps5)Quadriceps6)Illiopsoas7)Sartorius

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Musclesoftheheadandneck: Sternomastoid,amuscleattachedtothemastoidprocessofthetemporalboneandtothesternum.Thispairofthemuscleswhenusedtogetherflextheandhead.Separatelytheyheldtoturntheheadtooneside.

Trapezius,alargediamondshapedmuscle,attachedtotheocciputanddorsalvertebrae.Itdrawsbacktheshouldersandextendsthehead,thushelpingingoodposture.

MusclesthatmovetheupperArm:Deltoidatriangularmusclecoveringtheshoulderjoint,andattachedtotheshoulderblade,collarboneandhumerus.Itraisestharmoutwardstoshoulderlevel(abduction).

Pectoralisamusclecoveringthefrontofthechest,attachedthehumerus.Itadductsthearm(drawsthearmacrossthechest).

Latissimusdorsialargemuscleoftheback,attachedtotheupperposteriorpartofthehumerus.Itadductsthearm,drawingitdownandback.

Musclesthatmovetheforearm: Bicepsamusclewithtwoheadsfromtheshoulderblade.Itliesinfrontofthehumerusandisattachedtotheradius.Itflexestheelbowjoint.

Tricepsamusclewiththreeheadsfromtheshoulderbladeandhumerus.Itliesalongthebackofthehumerusandisattachedtotheulna.Itextendstheelbowjoint.

Musclesthatmovethethigh: Iliopsoasmusclethatpassesfromthefrontofthelumbarvertebraeandtheilium,tothefemur.Itflexesthehipjoint.

Glutealsmusclesofthebuttocks.Attachedtotheposteriorsurfaceoftheilium,andsacrum,andtothefemur,theyextendthehipjoint.

1

2

3

4

5

6

Fig2.13MusclesoftheBody(Posterior)

1)Sternomastoid2)Trapezius3)Deltoid4)GluteusMaximus5)Hamstrings6)Gastronemus

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MusclesthatmovethelowerLeg:Quadricepsfemorisaverystronggroupoffourmuscles,whichcoverthefrontofthethigh.Passingfromtheiliumandfemur,theyareattachedtothepatellaandsobythepatellarligamenttothetibia.Theyextendedthekneejoint.

Harmstringsfromtheischiumandfemurtothetibiaandfibula,thismuscleliesatthebackofthethighandflexesthekneejoint.

Sartoriusfromtheiliacspinetotheinnersideofthetibia,thislongthinmusclehelpstoabductandflexboththehipandknee,aswhensittingcrosslegged.

Musclesoftheabdominalwall:Rectusabdominisfromthesternumandcostalcartiliagestothepublicbone,thesearetwostraightmuscleformingthefrontwalloftheabdomen.theycauseflexionofthespine,andhelpindefaecationandinchildbirth.

Obliquemuscles,externalandinternal.Theseformthesidewallsoftheabdomen,andhelpsinturningthetrunk.

MusclesthatmovetheChestwall: Intercoastalssituatedbetweentheribs,thesemuscleselevatetheribsforbreathing.

Diaphragm is a dome shapedmuscle whichdivides the chest from the abdomen. It isattachedtothesternumandlowerribs,andtothelumbarvertebrae.Itsmovementsareessentialforbreathing.Itflattenswhencontractedandthusthechestisenlargedforbreathingin.Ithelpsalsobydownwardpressureindefaecation,passingurine,andinchildbirth.

NERVOUSSYSTEM

Thisfunctionslikeatelephonesystem.Withthebrainastheheadoffice,andnerveslikethetelephonewirescommunicationtakesplacewithallpartsofthebody.Bymeansofnumerousmessagessentandreceived,thevarioustissuesandorgansofthebodyworkinharmony

Thenervoussystemhastwoparts:

1) Centralnervoussystem madeupofthebrainandcranialnerves,spinalcord,andspinalnerves.

Itcontrolsthevoluntarymusclesofthehead,trunkandlimbs.

Itreceivesmessagesfromsenseorganssuchasskin,eyesandears.

2) TheAutonomicnervoussystem thisismadeupofsympatheticandparasympathetic

nerves.Itcontrolsinvoluntary(internal)musclesandglandularsecretions.

NerveTissue:NerveTissue,ofwhichthesenervoussystemsarecomposed,issofttissuemadeupofnervecellsandnervefibres.Thecellsmassedtogether,asinthebrain,formwhatiscalledthegraymatter.Thenervefibresformwhitematter.

Nervefibresareeachconnectedwiththeirownnervecells,formingaunitcalledaneurone.Messagsjumpacrossfromoneneuronethroughitsfirbestothenextneurone.Thefibresofsomeneuronesareverylong(eg.thoseinthelimbs)andtheyaregroupedtogetherasvisiblewhitenervetrunks.

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Nervesarethreetypes:

1) Sensorynerves,whichcarrymessagesfromallpartsofthebodytothebrainandspinalcord.Theyenablethebodytoreactforitsprotection.

2) Motornerves,whichtakemessagesfromthebrainandspinalcordtomusclesandglandsinallpartsofthebody.theystimulateactivity.

3) Mixednervesconsistsofbothsensoryandmotornervefibres,sotheycarrymessagesinbothdirections.

Thebrain:

Thisisthemostimportantpartofthecentralnervoussystem.Itiswellprotectedinthecranialcavityandhasthefollowingparts.

1) Thecerebrumorforebrain. 2)Thecerebellumorhindbrain.3)Themidbrain. 4) Thebrainstemconsistingofponsandmedulla.

TheCerebrum: Thelargestpartofthebrain,fillsthefrontandtoppartsoftheskull.Ithastwopartsrightandleft.Thesetwopartscontroltheoppositesidesofthebody,sothatdiseaseorinjuryoftherightsideofthecerebrumparalysestheleftsideofthebody,andviceversa.

FunctionsofCerebrum:

1) Frontallobe:

a)Motorcenterscontrollingvoluntarymuscles.b)Speechcentre.c)Mentalpowerssuchasmemory,intelligenceandwill.

2) Parietallobe:Thesensorycentersforsensationsoftouch,pain,heat,coldandpressure.

3) Temporallobe:Forhearing.

4) Occipitallobe :Forvision(sight).

TheCerebellum: Thecerebellumissituatedunderneaththecerebrumattheback.Itissmallerthanthecerebrum.Italsohasarightandleftsides.Itsactivitiesareunconsciousandnotundercontrolofthewill.

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1

5

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Fig2.14TheBrain

1)Cerebrum2)MidBrain3)Cerebellum4)Ponsvaroli5)MedullaOblongata

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FunctionsoftheCerebellum:

1)Helpstomaintainbalance 2)Helpstomaintainmuscletone.

3)Coordinatestheworkofmuscles.

TheMidBrain:Thisconsistsoftwoshortstalksofnervetissueattachedtothelowerpartoftherightandleftsidesofthecerebruminthecentre.

FunctionsoftheMidBrain:

1) Actsasapathwayformessagestoandfromthecerebrum.

2) Containsreflexcentresforvisionandhearing.

3) Containscentersforcontrollingbodytemperature(hypothalamus),theemotionsandsexualresponses.

Thebrainstem: TheBrainstemlikeastalkconnectingthebrain,withthespinalcord,hasthefollowingparts.

1)ThePons:Thispart,situatedbelowtheMidBrain,islikeabridgeconnectingthetwosidesofthecerebellumandthemidbrainwiththemedullabelow.

2)themedulla.Thisjoinstheponsabovetothespinalcordbelow.Itlookslikethespinalcordbutisalittlethicker.Itliesjustinsidetheskull.

FunctionsoftheMedulla:

1) Connectsthebrainwiththespinalcord,andconveysmessages.Itisinthemedullathatcerebralnervefibrescrossovertotheoppositeside.

2) Containnervescenters,whichcontrolthevitalfunctionsofcirculationandrespiration.

3) Containreflexcentersofswallowing,vomitingandcoughing.

CranialNerves:

Thereare twelvepairs ofcranialnerveswhichcomeoutfromthebrainandbrainstem.Theypassthroughholesintheskulltotheeyes,ears,face,tongue,throat,etc.

Thetenthcranialnervecalled vagus,givebranchestothelarynx,lungs,andheartanddigestiveorgans.Thevagusnervefunctionsaspartoftheautonomicnervoussystem.

TheSpinalCord:

Thespinalcordisacordofnervoustissue,thethicknessofalittlefingerandabout12cmlong.Itliesinsideacanalformedbythevertebrae.Itconnectsabovewiththemedullawherethebackoftheneckjoinstheskullandextendstothelevelofthefirstlumbarvertebrae.

FunctionsoftheSpinalCord:

1)Receivesmotorimpulsesfromthefrontallobeofthecerebrum,andpassesthemontomusclesviathespinalnerves.

2)Receivessensationsfromtheskinandothertissuesandrelaysthemessagetothebrain.

3) Reflex action.This is the quick response in the spinal cord itself.Eg. If you touchsomethinghot,themessagereceivedinthespinalcordisimmediatelyflashedtothemusclesofthearmbeforethenewsreachesthebrainyouhavetakenyourhandaway.

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Themeningesandcerebrospinalfluid(C.S.F.)

Thebrainandspinalcordarecoveredbythreemembranescalledmeninges.

1)Duramateristheouter,thickelasticcover.Itlinestheskullandspinalcord.

2)Arachnoid,athinmiddlemembrane.Itisaloosecoveringandunderisaspacecalledtheca(subarachnoidspace)containingcerebrospinalfluid(C.S.F.)

3) Piamater isclosesttothenervetissueandcarriesbloodvessels.Whenthesemembranesgetinfected,theconditionisknownasmeningitis.

CerebroSpinalFluid:(C.S.F.):Thisisaclearfluid,whichcirculatesbothinsideandoutsidethebrainandspinalcord.Alittlecerebrospinalfluidissometimesremovedbylumbarpuncturetohelpindiagnosingdiseaseofthenervoussystem.

FunctionsofCerebrospinalFluid:

Itactsasawatercushiontoprotectthebrainandspinalcordfromshocksandjarring.

Itnourishesandcleanses,washingawaywaterandtoxins.

TheAutonomicNervousSystems

Itisthesecondsystemofthenervesthatcontrolsthemovementsoftheinvoluntarymusclesandthesecretionoftheglands.Wehavenocontroloverthesenervesalthoughtheyarecloselyconnectedwiththecentralnervoussystem.

IntheANStherearetwosetsofnerves,whichopposeeachotherinaction.

SympatheticSystems:Thisconsistsoftwochainsofganglia(groupsofnervecells)oneoneachsideofthevertebralcolumn.Thegangliaareattachedbyfibrestothespinalnerves.

Thesympatheticnervesarestimulatedbytheemotionssuchasfear,excitementandanger.Theresults of the sympathetic nerve stimuli are: 1) dilated pupils 2) the heart beats quicker3)breathingisquickeranddeeper4)thebloodpressureisraised5)digestionissloweddown6)sweatingisincreasedand7) analandurethralsphincterstightenup.

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Fig2.15TheMeninges

1)Piamater2)ArachnoidMater3)Duramater4)Brain

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ParasympatheticSystem: Thissystemisincontrolduringnormalquietliving.Certaincranialnerves(thevagusespecially)havesuchactionsasthefollowing.1)pupilsoftheeyescontract.2)increaseinsalivaflows3)digestionandperistalsisarestimulated.

THECARDIOVASCULARSYSTEM

Thecardiovascularsystemisthetransportsystemofthebody.Itisthemeansbywhichfood,oxygen,waterandotherrequirementsareconveyedtothetissuecalls,andtheirwasteproductsarecarriedaway.

Theheartisimportantorganofthecirculatorysystem.Itisplacedbehindbreastboneandwithinthe thoracic cage. It is hollow muscular organ. It is enclosed in a sac known as thepericardium.Itisaboutthesizeofapersonsclenchedfistandweighsaround300gminamanand250gminawoman.

Thehearthasfourchambers,twoatria(upper)andtwoventricleslower.Valvesconnecttheupper and lower chambers. The right and left sides of the heart are totally separated by amuscularwallandthereisnocommunicationbetweenthem.

The rightsideof theheart receivesthedeoxygenated (impure)bloodcollectedfrom thedifferentpartsofthebodythroughsmallandbigveins,whichentersthelungs.Inthelungsthebloodisoxygenatedandcarbondioxideandmetabolicwasteareremoved

Theleftsideoftheheartreceives(pure)bloodfromthelungsandsuppliesittotheentirebodythroughthemajorbloodvessel(aorta)anditsnumerablebranches(arteriesandcapillaries).

Theleftventriclegeneratesgreaterpressurethantherightventricletoenabletheboldtobepumpedthroughoutthebody.Hencetheleftventricleismorethickerandmoremuscular.

Thecoronaryarteriesbranchout(leftandrightcoronaryarteries)fromtherootoftheaortanearitsoriginfromtheleftventricle.Boththecoronaryarteriesbranchofintosmallervessels,whicharedistributedalloverthesurfaceoftheheart.Forefficientpumping,itisnecessaryforthehearttobeatatareasonablerateof6090beatsperminute,whichisachievedthroughcontrolledelectricalimpulses(conductivesystem).

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2

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Fig2.16TheHeart

1)Aorta2)LeftAtrium3)LeftVentricle4)ApexoftheHeart5)Aorta6)SuperiorVenacava7)RightAtrium8)SemiLunarValves9)RightVentricle10)InferiorVenacava

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FunctionsofHeart:

1)Itdrawsbloodbackfromthecapillariesandveins.2)Itsendsbloodintothelungswhereitisoxygenated.3)Itsendsbloodthroughtheaortatoallthepartsofthebody.

Thepartsofthecirculatorysystemare:

1)Blood.2)Theheart,whichisthepumpforcingbloodintothecirculation.3)Thebloodvesselsinwhichthebloodtravels.4)Thelymphaticsystemiscloselyconnected,andcanbeconsideredapartofthecirculatorysystem.

THEBLOOD

About6litresofbloodcontinuouslycirculatesthroughtheheart,andbloodvesselsinallpartsofthebody.Itisastickyredfluidisslightlyalkalineinreaction.Itismadeupofaliquid(plasma)andsolids(thebloodcells).

Plasmaisapaleyellowfluidconsistingof

Water90%

Salts,inlcudingsodiumchloride0.9%

Proteins(albumin,globulin,fibrinogen)

Nutrients,suchasglucose,fats,aminoacidsvitaminsandminerals

Wasteproductssuchasureaandcarbondioxide

Antibodiesandantioxinsforresistancetodiseasegerms,

Hormonesproducedbytheendocrineglands.

Substancesforbloodclotingandforpreventingclotingofblood.

Plasmaisimportantforthelifeofthetissuecells,conveyingtothemwaterandnourishment,andcarryingawaytheirwasteproducts.

12 3 4

5 6 7Fig2.17BloodCells

1)Platelets 2)RedBloodCells 3)WhiteBloodCells 4)Monocyte5)Neutrophil6)Esoniophil 7)Basophil

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Bloodcells(Bloodcorpuscles)

Therearethreemaintypes

RedbloodcellsorErythrocytes

WhitebloodcellsorLeucocytes

BloodPlateletsorThrombocytes.

Redbloodcellsareformedinthebonemarrowandwearoutinaboutthreemonths,soneedplacing.Theyareverytinydiscwithnonucleus,andarefilledwithhaemoglobin,whichismadefromironandprotein.Haemoglobingivestotheblooditsredcolour.Thenormalamountofhaemoglobinis14.515gms.per100ml.ofblood.Lackofirontomakehaemoglobiniscommoncauseofanaemia.RBCshavetheimportantfunctionofcarryingoxygenfromthelungstothetissuecells.Whenunitedwithoxygeninthelungs,thehaemoglobinhasabrightredcolur.Whenthebloodreturnsaftergivingupitsoxygen,itischangedtoadullredcolour.

WhiteBloodcells

Whitebloodcellshelptofightinfection.Therearetwomaintypes.

1) Leucocytesareproducedinthebonemarrow.Theycanchangeshapeandsqueezethroughthesmallboodvesselwallsinordertofightgemsthathaveenteredthetissues.Manydieinthefightandbecomepuscells.Inacuteinfectionmanymoreleucocytesareproducedtohelpinthefight(leucocytosis)

2) Lymphocytesareproducedinthespleenandlymphglands.Theyarelessmobilebuttheyarehelptofightinfectionespeciallywhenitischronic.

BloodPlateletes

Bloodplateletesareproducedinthebonemarrow.Theyhelpintheclotingofblood.

FunctionsofBlood:

Carriesoxygentothetissuesbymeansofredbloodcells.

Carriesfoodtothetissues.

Carriesawaywasteproductsfromthetissuestotheexcretoryorgan.

Carrieshormonesfromtheglandstothetargettissues.

Fightsgerminfectionbymeansofthewhitecellsandantibodies.

Distributesheatandhelpstomaintainbodytemperature.

Helpstomaintainwaterbalanceinthebody.

TheLymphaticSystemandSpleen:

Thelymphaticsystemisaspecialtypeofcirculatorysystem.Itiscomposedof1)Thelymph.2)Thelymphaticvessels.3)Thelymphglandsornodes.

Lymphisafluidlikeplasmaandthetissuefluidbutincasesofinfectionitmaycontainbacteria.Lymphisreallythetissuefluid,whichfindsitwayintothelymphaticvessels.

LymphaticVessels:Lymphaticstartintissuespacesbetweenthecellsandstartliketheveins.Insidethemarethevalveswhichhelptheflowoflymphtowardsthetwolargestlymphaticvessels.

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LymphGlands aresmallbeanshapedstructures,situatedalongthecourseofthelymphatic.Theyarefoundmainlygroupedtogetherintheneck,axilla,andgroinsandinthepelvicandabdominalcavities.Lymphoidtissueisalsofoundinthetonsils,pharynxandintestines.

FunctionsofLymph:

Lymphglandshelptoprotectthebodyfrominfectionby

1) Filteringthelymphtopreventgermsfromgettingintothebloodstream,andfightingtoovercomethem.

2) Producingnewlymphocytesfortheblood.

DIGESTIVESYSTEM

Digestionistheprocessbywhichthecomplexformsoffoodmaterialsarebrokendownintosimplerformoffoodmaterialssuitableforabsorption.

Oncethefoodisdigested,itmustbetransferredtothebloodstreamandtheprocessbywhichthis transfer occurs is called absorption.Digestion and absorption are two chief functions ofthedigestivesystem.

TheAlimentaryCanal:

Thealimentarycanalisalongmusculardigestivetubeextendingthroughthebody.Itisabout750cminlength.Itconsistsofthefollowingparts:

1) Themouth. 2)Oesophagus 3)Stomach 4)Smallintestine

5)Largeintestine. 6)Rectum 7)Analcanal.

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2

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Fig2.18DigestiveSystem1)Mouth2)Oesophagus3)Stomach4)Pancreas5)Largeintestine6)Smallintestine7)Rectum8)Liver9)GallBladder

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Thegastrointestinaltractconsistsatubecomposedoffourprincipallayersfromoutsideinwards:

1)Tunicaadventitiaorserouscoat

2)Tunicamediaorthemuscularcoat.

3)Tunicaintimaortheinnerliningofthebloodvessel.

FunctionsofDigestiveSystem:

1)Breakdownthefoodsubstancesintosmallparticles

2)Digestionoffoodsubstances.

3)Absorptionoffoodsubstances.

4) Excretionofundigestedfoodandtoxicsubstances.

Thealimentarycanal,whichisacontinuous,passagewaybeginningatthemouth,wherethefoodistakeninandterminatingattheanuswherethesolidproductsofdigestion,whicharenotabsorbed,areexpelledfromthebody.

Theaccessoryorganswhicharevitallynecessaryforthedigestiveprocess,donothappentobethepartofthealimentarycanal.

PhysiologyofDigestion:Digestiontakesplaceisthreepartsofthealimentarycanal.Theyare:1)Mouthwiththehelpofsalivafromthreepairsofsalivaryglands, 2)Stomach withthehelpofgastricjuicefromthestomachwalland 3)Smallintestine withthehelpofpancreaticjuicefromthepancreasbilejuicefromtheliverandtheintestinaljuicefromthesmallintestine.

TheMouth: Themouthisalsocalledtheoralcavity.Inthemouththereareabout32teeth.Theyare

(1)Molars12 (2)Premolars8 (3)Canines4 (4)Incisors8

Theteethhelptobreakdownthefoodsubstancesintosmallparticles.Amuscularorganprojectsintothisspaceiscalledthetongue.Ithelpsinchewingandswallowingandisoneoftheprincipalorgansofspeech.

Thetonguehasonitssurfaceanumberoftastebudsbymeansofwhichwecandifferentiatesensationoftaste.(bitter,sweet,sourandsalty)

Inchewing,theteethgrindthefoodintopieceswhilethesecretionofsalivamoistensandlubricatesthefood.

Salivaisajuicesecretedbythreepairsofsalivaryglandsinthemouth.theyare

1) Theparotid:locatedinfrontandbeloweachexternalear.

2) Thesubmaxillary:locatedbetweenthemandibleandthemuscleofthefloorofthemouth.

3) Thesublingualgland:locatedinfloorofthemouth.

Salivary secretion is a reflex process, both conditioned and unconditioned reflexes areinvolved.Anewborninfantsalivateswhenfoodisplacedinitsmouth.Butthesightandsmelloffooddoesnotproduceanyreaction.

Laterbyassociatingthesightandsmelloffoodwithitstaste,thechildlearnsthatthefoodhascertain qualities and these very qualities are after wards capable of eliciting salivarysecretion.

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FunctionsofSaliva:

1) Itkeepsthemouthmoistandhelpsinspeech.2) Ithelpsintheprocessofmasticationofthefoodstuffandinpreparingitintoabolussuitable

fordigestion.3) Itdiluteshot,irritantsubstancesandthuspreventsinjurytothemucousmembrane.4) Salivacontainstwoenzymes.PtyalinandMaltase,whichconvertsstarchyfoodintosugars.5) Salivahelpsinthesensationoftaste.6) Ithelpsheatloss.Thisismainlyfoundinanimals.Whentheybecomehot,moresalivais

secretedcausinggreaterheatloss.7) Ithelpsintheexcretionofcertainsubstanceslikedrugscontainingmercury,leadandiodine.

Digestioninthemouth

Thefoodischewedandsalivathefirstofthedigestivejuicesactsonit,softensitsothatitcanbeeasilyswallowed.Salivacontainstwoenzymes.

(1)Ptyalin (2) Maltase.

Ptyalinsplitsstarchintomaltoseandmaltaseconvertsmaltoseintoglucose.

Oesophagus :

Theoesophagusisatubeconnectingthepharynxandthestomach.Itconveysthefoodfromthemouthtothestomach.

Stomach

Thestomachisanenlargedsectionofalimentarytube.Bothendsofthestomachareguardedbyvalveswhichnormallypermitthepassageofsubstancesinonlyonedirection.

Theproximalendisguardedbycardiacsphincterandthedistalendofthestomachisguardedbypyloricsphincter.

Stomachactsasapouchforholdinglargequantitiesoffoodsothatfrequentfeedingcanbeavoided.The stomachmixes up the food thoroughly by itsmovements. It also destroys thebacteriabythehighacidity.

DigestionintheStomach

The foodmaterial after being broken downbymechanical grinding and having beenconvertedintoaboluswiththesalivareachesthestomach,whichpoursalargequantityofgastricjuiceeveryday.

Themechanismofproductionofgastricjuiceisachemicalorhormonalinnature.Whenthedigestedfoodisincontactwithgastricmucosa,achemicalextractisformed.Itisnamedasgastrinandbelongstothegroupofgastrointestinalhormones.Thiscausesthedischargeofgastricjuice.

Thegastricjuicecontainsmainlyhydrochloricacidandenzymes.

1) Pepsin. 2)Rennin 3)Lipase

FunctionsofHydrochloricAcid:

1)Killsbacteriapresentinthefood.

2)Softenstheconnectivetissuesofmeat.3) Convertsinactiveformofpepsinogenintoactiveformofpepsin.

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FunctionsofEnzymes:

1)Pepsinconvertsproteinintopeptones.

2)Renninconvertstheindigestibleproteinofmilkintoeasilydigestibleone.

3) Lipaseconvertsfatsintofattyacidsandglycerol.

LiverTheliverisoneofthelargestandimportantorgansituatedontherightsideoftheabdomen.Bileis

secretedbytheliver.

FunctionsofLiver:

1) Theproductionofbilefromthepigmentofbrokendownredbloodcells.

2) Theremovaloftoxinsthathavebeenabsorbedfromtheintestine

3) Thestorageofsimplesugarintheformofglycogenwhichisreleasedasneededintheformofglucose.

4) ThestorageoffatsolublevitaminsincludingA,D,EandK.

5) Themanufactureofheparin,whichpreventsclottingofthebloodinthebloodvessels.

6) Theformationofantibodieswhichactsagainstdiseaseproducingorganisms.

7) Theproductionofcertainbloodplasmaproteinssuchasfibrinogenandalbumin.

8) Theremovalofawasteproductcalledureafromaminoacids.

BileJuice:

1)Intheabsenceofbile,fatsarenotdigestedproperlywhichresultsinfattydiarrhea.Thusbileisessentialfordigestionthoughitdoesnotcontainanydigestiveenzymes.

2)Thebileistakenbythehepaticductandisstoredinthegallbladder,whichissituatedonthelowersurfaceoftheliver.Thebileisconcentratedandsenttotheduodenumthroughthecysticductwhenchimefromthestomachenterstheduodenum.

3)Bilecontainsbilesalt,bilepigment,mucinandwater.ThetwopigmentspresentinthebilearecalledBilirubinandBiliverdin.Thesepigmentsgivecolourtothefaecesandurine.

Duetoliverdamageorobstructionofthebileduct,bilirubincollectsinexcessquantitiesinbleedandchangesthecolouroftheskinandtheeyes.Theremaybechangesinthecolouroftheurinealso.Thisiscalledjaundice.

FunctionsofBileJuice:1)Itstimulatesthefunctionsoftheproteolyticenzymesandtheamylase.

2)Itdissolvesfattyacidandglycerol.

3)Itcoordinateswithlipasetoconvertthefatintofattyacidandglycerol.

4)Acidicnatureoffood.

Pancreas

Pancreasanelongatedstructurelyingacrosstheposteriorwalloftheabdomen.Itisanexocrineaswellasanendocrinegland.Thepancreasnotonlyproducesthepancreaticjuicebutalsosecreteshormoneseg.Insulinandglucacon.Itisreleaseddirectlyinthebloodwhichregulatesthebloodglucoselevel.Thepancreaticjuicecontainsthreeenzymes.Theyare

1

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1) Trypsin. 2)Amylaseand3)Lipase.

Besidestheseenzymespancreaticjuicecontainslargequantitiesofsodiumbicarbonatewhichneutralizesthehydrochloricacidpresentinthegastricjuicesecretedbythestomach.

TheSpleen: Thisisadarkpurpleorgansituatedintheleftsideoftheupperabdomen,behindthestomach.

FunctionsoftheSpleenare:

1) Itproducesnewlymphocytesfortheblood.

2) Ithelpstofightinfection.

3) Itdestroyswornoutredbloodcellsandremovestheironfromthemtobereused.

4) ItactsasareservoirforRedBloodCells,whichitreleasesintimeofneed,suchasasuddenhaemorrhage.

Small Intestine

Thesmallintestineisabout600cmlonginadultextendingfromthepyloricsphincterofthestomachtointestine.Thefirst25cmor30cmofthesmallintestineiscalledtheduodenumfollowedbythejejunumandtheremainderistheileum.

DigestionintheSmallIntestine:

Thefoodinthestomachispartiallydigestedbythegastricjuice,butthesmallintestineistheorganinwhichthecompletionofthedigestionandabsorptionoccurs.

Intheduodenumthereisanopeningintowhichleadtwoductscarryingdigestivejuicesi.e.,pancreaticjuiceviathepancreaticductfromthepancreasandtheother,bile,viabileductfromtheliver.

Bileisnotprimarilyadigestivejuicebecauseitcontainsnoenzymebutithelpsinthedigestionoffats.Thebilesaltemulsifiesfatsandhelpsthepancreaticlipasetoactanddigestiteasily.Thepancreaticjuicecontainsthreepowerfulenzymes.

Theyare:

1)Pancreatin:convertscarbohydratesintosimplesugarslikeamylaseglucose,fructoseandgalactose.

2)Trypsin:convertspeptonesintopolypeptides.Inthebeginningtrypsinispresentintheformofinactivetrypsinogen.

Thistrypsinogenisconvertedintoactivetrypsinbyactionofenterokinasewhichissecretedinthesmallintestine.

3)Pancreatic lipase:convertsfatsintofattyacidsandglycerol.

Afterpancreaticdigestion,thefoodwhichisnowcalledchymeproceedsfurtherintheintestine.Hereitcomesintocontactwithsuccusentericuswhichisajuiceproducedbythesmallintestine.Succusentericuscontainsthreeenzymes.Theyare

1)Pepsin:Itconvertspolypeptidesintoaminoacids.

2) Nucleotidase :ConvertsNucleotide,intonucleoside.

3)Nucleosidase:Convertsnucleosidesintopentose,purine,andpyramidin.

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Italsocontainsthreesugarsplittingenzymescalledlactase,maltaseandsucraseconvertingtherespectivesugarsintosimplesugars,mostlyglucose.Italsohaslipase,whichactsonfatsandconvertsthemintofattyacidsandglycerol.

Thefinalproductofdigestionofthecarbohydratesisglucosewhiletheproteinsareaminoacidsandfatsarefattyacidsandglycerol.

LargeIntestine

Thelargeintestineisasthenameimplieshasthelargerdiameterthanthesmallintestine.Itisabout150cminlength.Thesmallintestineopensintothelargeintestine.

Thereisasmallpouchatthebeginningpartofthelargeintestine.Thispouchiscalledthecaecum.Largeintestineconsistsofascendingcolon,transversecolonanddescendingcolon.

Rectumandanalcanal:

Thedescendingcolonoflargeintestineopensintolastpart,therectumandanalcanal.Itisabout15cmto20cmlong.Therectumservesasatemporarystorageareafortheindigestibleandnonabsorbablesubstances.

Thenarrowportionofthedistalpartofthelargeintestineiscalledtheanalcanal,whichleadstotheoutsidethroughanopeningcalledtheanus.

AbsorptionofFood:

Absorptionistheprocessbywhichwater,minerals,vitaminsandendproductsofdigestionareabsorbedthroughthemucosaofalimentarycanal(especiallythesmallintestines)intobloodstreameitherdirectlyorvialymphaticvessels.

In the stomach there is little absorption.Water, alcohol, glucose and simple salts areabsorbedtocertaindegree.Themainabsorptionoccursinsmallintestinesespeciallyinthelower(ileum)part, the upper part of the small intestine is mainly associated with the process ofdigestion.

Themucousmembraneofsmallintestineiscoveredwithminutefingerlikeprojectionsknownasvilli.Eachvilluscontainsarteriole,avenule,acapillarynetworkandalacteal(lymphaticvessel).

1

2

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Fig2.19Villus

1)Epithelialcells2)Bloodvessels3)Lacteal

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Nutrientsthatdiffusethroughtheepithelialcellswhichcoversthevillusareabletopassthroughthecapillarywallsandthelactealenterstheblood.

About90%ofallabsorptiontakesplacethroughoutthelengthofthesmallintestine.Theother10%occursinthestomachandlargeintestine.

Both monosaccharide and amino acids are absorbed by a positive pressure gradientbetweentheintestinalcontentandthebloodaswellasbyanactiveprocessinvolvingenzymaticreactionsandtransportedinthebloodstreamtotheliverviathehepaticportalsystem.

Theexcessamountofglucoseisconvertedintoglycogenandstoredintheliver,whenneedarisesglycogenisconvertedintoglucoseandisutilizedbythebody.

VitaminKwhichissynthesizedbythebacteriainthecolonareabsorbedfromthelargeintestine.Largequantitiesofwaterarehoweverabsorbedfromthelargeintestineandthefluidcontentofthesmallintestineareconvertedintothepastyconsistencyandejectedthroughtheopeningcalledthe anus.

Movementsofthegastrointestinaltract:

Deglutition istheprocessbywhichthemasticatedfoodistransportedacrossthepharynxandreachesthestomach.Duetocontractilemovementsofthestomach,thefoodiswellmixedupwithgastricjuice.

Afterbeinginthestomachfor3or4hoursthepyloricsphincteropenspushingthefoodintotheduodenum.Theintestineshowsthreeimportanttypesofmovements.Theyare

1)PendularMovement:thesemovementsareinducedbycontractionsofthecircularandlongitudinalmusclesoftheintestine.Thismovementcontributestothethoroughmixingofchimewiththedigestivejuice.

2) SegmentalMovement:thismovementoccursbythecontractionofthecircularmuscles,whichproducestransversefolds,dividingtheintestineintoshortsegment.

3) PeristalticMovement:itisthewavelikecontractionofthealimentarycanal,whichpropelsthefoodthroughthegastrointestinaltract.

RESPIRATORYSYSTEM

Respirationistheprocessofgaseousbetweenanorganismanditsenvironment.Inthehigheranimals,andmanthegaseousexchangebetweenthetissuesandenvironmentistermed asInternalortissuerespiration.

Theexchangeofgasesbetweenthebodyandtheenvironmenttakingplaceinthelungsistermedas externalrespiration.Theexternalrespirationconstitutesprocessesof inspiration and expiration.

Inspirationisanactivemuscularcontractionwhileexpirationismerelyapassiveactoftherelaxationofrespiratorymuscles.

Structureofrespiratorysystem:

Therespiratorysystemisresponsiblefortakinginoxygenandgivingoffcarbondioxideandwater.Itisdividedintotheupperrespiratorytractandlowerrespiratorytract.

1) Theupperrespiratorytract:Nose,Mouth,thethroat,pharynx,thelarynxandnumeroussinuscavitiesinthehead.

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2)Thelowerrespiratorytract:Thetrachea,thebronchiandthelungs,whichcontainbronchialtubebronchiolesandalveoliorairsac.

Thetwo lungs,whicharetheprincipalorgansoftherespiratorysystem,aresituatedintheupperpartofthethoraciccage.

Theyareinertorgans,i.e.theydonotworkbythemselves,butfunctionwiththehelpofamuscularwallknownasthediaphragm.

Thepharynxisatubeapproximately12cminlength,whichisacommonopeningforbothdigestiveandrespiratorysystem.

Itconnectstheoralcavitytotheoesophagus(foodtube)andthenasalcavitytothelarynxandwindpipe.Theopeningintothelarynxisovalinshapeandguardedbytheleaflikeepiglottis.

The epiglottis foldsdownovertheopeninglikeatrapdoorwhilefoodorliquidisbeingswallowed,itpreventstheentryofforeignsubstancesintotherespiratorypassageways.

Theclosureofepiglottis,whenweswallow,isareflexactionandcanbeinterferedwith,ifoneattemptstotalkandswallowatthesametime.

Ifthishappensonemaychoketodeathintheabsenceofimmediateassistance.Fromthepharynx,airpassesthroughthetrachea,whichis12cmlongand1.5cmindiameter.Thetract,consistsofalargenumberofCshapedcartilagerings.Thelarynxorthe voicebox isatthetopofthetrachea.Itisthevocalcordsinsidethebox,whichbyitscomingtogetherandgoingawayfromoneanotherproducesdifferentsounds.

Thetracheabranchesatitslowerendintotherightandleftbronchiwhichentersthelungs,withinthelungsthosepassagewaysrepeatedlydivide,formingmicroscopictubescalled bronchioles.

Eachbronchioleendswithseveralclustersofmicroscopicelasticairsacscalledalveoli,whicharethefunctionalunitsoflungs.Thisresemblesbunchofgrapes.

Thepairedlungsliewithinthelargecavityofthechest,thethoraciccavity.Thelungsaregrayishcolourandarespongyinappearance.

Therightlungshavethreelobesupper,middleandlower,andtheleftlunghastwolobesupperandlower.Thefloorofthethoraciccavityisformedbyadomelikemuscularstructurecalled diaphragm. Eachlungisenclosedbytwolayersofmembranecalled pleuralmembranes.

Fig2.20Lungs1)Larynx2)Trachea3)Bronchus4)Lung

1

2

3

4

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Thechestcavityisalsolinedwiththismembrane.Thislayerbeingknownastheparietalpleura,whilevisceralpleuralinethelungparenchyma.

Respiration

Webreathecontinuouslyfrombirthtodeath,dayandnightinhealthanddisease.

Respirationmaybedefinedasthemechanicalprocessofbreathinginandout,afunctionwhichinvolvesboththerespiratorysystemandmusclesoftherespiration.

The2phasesofbreathingare

1. Inhalationduringwhichairisdrawnintolungs

2.Exhalationwhichreferstotheexpulsionofairfromthealveoli

Inhalation

Thediaphragmwhenrelaxedisaflatteneddomeshapestructurepointingupwardstothelungs.Duringtheprocessofinhalationitcontracts.

Itflattens,pullsdownthethorax,increasesthevolumeofthethorax,andthusdecreasestheatmosphericpressureinthelungs.Thiscausesairtorushinduringrespiration.

Exhalation

Duringtheprocessesofexhalation,thediaphragmrelaxes,thethoraxispushedup,thevolumedecreasesandtheatmosphericpressureincreasesandairrushesoutofthelungs.

Theinspiredair,whichcontainsoxygen,passesdownintothebillionsofminuteairchambersoraircellsknownasalveoli,whichhaveverythinwalls.Aroundthesewallsarethecapillariesofthepulmonarysystem.

Itisatthispointthatthefreshairgivesoffitsoxygentothebloodandtakescarbondioxidefromthebloodbydiffusion,whichisthenexpelledwiththeexpiredair.

PhysiologyofRespiration:

Therespiratorycenterofthebrainislocatedinthemedulla,immediatelyabovethespinalcord.Fromthiscenternervefibersextenddownintothespinalcord.Fromtheneckpartofthecord,thesenervefiberscontinuethroughthephrenicnerve tothediaphragm.

Thediaphragmdoesnotcontinuetoworkifitiscutofffromitsnervesupply.Ifonenerveiscut,thediaphragmofthatsideisparalyzed.Thiscenterisgovernedbyvariationinthechemistryoftheblood.

IfthereisanincreaseinCo2intheblood,thecellsoftherespiratorycenterarestimulatedandtheyintermsendimpulsesdownthephrenicnervetothediaphragm.

RespiratoryRate:

Inadults,therespiratoryrateis14to18timesperminute.Childrenbreathsmoresuperficiallyandthereforehaveahigherrespiratoryrate.

Importanceofrespiration:

1) Itsuppliesoxygenandeliminatedthecarbondioxide.

2) Itexcretesvolatilesubstanceslikeammonia,ketonebodies,essentialoils,alcoholandwatervapour,etc.,

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3) Byadjustingtheamountofcarbondioxideelimination,ithelpstomaintaintheacidbasebalance.

4) Ithelpstomaintainthenormalbodytemperature.

5) Itisnecessaryforthemaintenanceofoptimaloxidationreductionprocessinthebody.

EXCRETORYSYSTEM

Duringthevitalactivityofthehumanandanimalbody,significantamountsoforganicdegradationproductsareproduced,aproportionofwhichisnotutilizedbycells.

These degradation productsmust be eliminated from the body.The end products ofmetabolismwhichhavetoberemovedfromthebodyarecalled excreta,andtheorgansthatremovethemarecalled excretoryorgans.

Thelungseliminatedcarbondioxideandwatervapourintotheenvironment.Thegastrointestinaltractexcretesasmallamountofwater,bileacids,pigments,cholesterol,certaindrugs(whenadministered into the body) salts of heavy metals (cadmium, iron, manganese) andindigestiblefoodresidues(faeces).

Theskinperformsitsexcretoryfunctionbysweatandsebaceousglands.Sweatglandsexcretesweat,whichcontainswater,saltsurea,uricacid,creatinineandothercompounds.

Themain excretory organs are the kidneyswhich eliminate in the urinemost of themetabolitesprimarilythosecontainingnitrogen.(Urea,ammonia,creatinine).

Kidneys:

Thekidneyisabeanshapedorganabout5cmlong,3cmwideand2cmthick.Theyaresituatedatbothsidesofthelumbararea.

Theweightofthekidneyisabout200250gms.Ontheinnerormedialborderthereisanotchcalledthe hilum atwhichregiontheartery,theveinandtheureterconnectwiththekidney.

Eachkidneyhasapelvis,wheretheurinecollects.Theurineisdrainedofffromthepelvisbytheureters.Theuretersendintheurinarybladder,whichcanholdabout800mlofurine.Theurethracarriestheurinefromthebladderandvoidsitconvenientintervals.

Inalongitudinalsection,thekidneyisseentoconsistofoutercortexandinnermedulla.Themedulla consists of 1018 conical or pyramidal shaped structures, known as the renalpyramids

Thebaseofarenalpyramidfacestowardsthecortex.Thepelvisthefunnelshapedupperendoftheureter.

Microscopicexaminationofmammaliankidneysrevealsthateachkidneyconsistsofaboutmillionnephron,whicharethefunctionalunitofthekidney.

Thenumberofnephronsvariesdependingonspecies.Thenephronconsistsoftheglomerulus,therenaltubules,thecollectingtubulesandtheassociatedbloodvessels.

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Theglomerulusisatuftofcapillaryvessels,whichisinvaginatedintoanepithelialcupshapedliningcalledtheBowmanscapsule.

Therenalarterydividesintoinnumerablebranchesandtheultimatedivisionsofthearteryformatuftofcapillariescalled glomerulus.

Thebloodpressureinsidetheglomerulusdrivesoutthefluidthroughitisopposedbytheosmoticpressure.ThisfluidthusdrivenoutiscollectedintheBowmanscapsule.

Thefiltrateinthecapsuleconsistsofalltheconstituentsofblood,excepttheplasmaproteinsandtheformedelementsofblood.Thisprocessisknownas ultrafiltration.

Thefiltratedthenpassestothedescendingascendingportionofloop(HenlesLoop)andthentotheconvolutedtubules(proximalanddistal)andfinallyreachesthecollectingduct.

A large number of substances are reabsorbed (reabsorption) by the tubules, a fewsubstanceadded(secreation)tothefiltrateandthefinalurineisformed.

Forexample,water,glucose,somesaltsandasmallfractionofureaarereabsorbedfromtheprimaryurineintotheblood.Usuallyabout200litersoffiltrateisformedperdayofwhichoneandahalflitersissentoutasurine.

Therefore, nearly 198 liters ofwater has to be reabsorbed every day by the kidneytubules.About80%ofthisreabsorptiontakesplaceintheproximaltubulesandtherestisabsorbedinthedistaltubules,andsentbacktothebloodstream.

Reabsorptioniscarriedoutwiththehelpof antidiuretichormonewhichissecretedintheposteriorpituitarygland.

Thuseachnephronisabletocleanorfilteraverylargevolumeofbloodwithoutcausingthebodytolosemuchofwaterorotheressentialmaterials.

Thecompositionoffinalurineradicallydiffersfromthatoftheprimaryurine.Itisdevoidofglucose,aminoacids,certainsalts(phosphatesandsodium)andhasaveryhighureaconcentration.

Fig2.21Kidney1)Cortex2)Medulla3)Pyramid4)Pelvix5)Ureter 4

2

1

35

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Theurinethusformedcollectsintothebladderthroughtheureterswhicharelong,slender,musculartubethatextendfromthekidneytothelowerpartoftheurinarybladder.

Thebladderisamuscularbagwhichcollectstheurineandvoidsitatintervalsthroughtheurethra.Whenthebladderisempty,themuscularwallbecomesthickandtheentireorganfeelsfirm

Theorganmayincreasefromthelengthof2or3inchesto5inchesormoreinches.

Amoderatelyfullbladderholdsabout800mlofurine.When400mlofurineiscollectedinthebladder,thenormaldesireformicturitionisfelt.Theprocessofexpellingurinethroughtheurethraiscalledurinationormicturition.

Theactofmicturitionisareflexaction.Itiscontrolledbytheactionofcircularmuscles,continuouswiththoseinthewallsofthebladderandintheurethra.

Urine

Normalurineisfaintyellowincolour,clear,withacharacteristicsodour.Thespecificgravityis1.010to1.020.NormallyurineiscomposedofWater96%Urea2%Salts2%

Thesaltsconsistsmainlyofsodiumchlorides,phosphatesandsulphates.Theaveragequantityofurinepassedin24hoursis1.5litres.

ENDOCRINESYSTEM

Theglandsofthebodymaybedividedintothosewithandexternalsecretion(exocrineglands)andthosewithInternalsecretion(endocrineglands).

Examplesofexocrineglandsarethesweat,lacrymalandmammaryglandswhichpasstheirsecretionalongtheductstotheexternalsurfaceofthebodyandtheglandsofthemouth,stomach,andintestinewhichpasstheirsecretionsalongductsintothealimentarytract.

Theendocrineorductlessglandontheotherhandhavenoductsoropeningstotheexterior.Theirsecretionarepasseddirectlyintothebloodstreamandtransmittedtothetissues.

Ahormoneisachemicalsubstanceproducedbytheendocrineglandsandtheiroverallfunctionistoregulatetheactivitiesofvariousbodyorgansandtheirfunctions.

Themainendocrineglandsinthebodyare

1)Thyroid 2)Parathyroid 3)IsletsofLangerhans

4)Adrenalgland 5)Pituitarygland 6)Sexglands.

ThyroidGland:

Thelargestoftheendocrineglandsisthethyroidwhichislocatedintheneckregion.Thethyroidglandweighs25gmsinahealthyadult.Ithastwoovalpartscalledthelaterallobesoneithersideofthetrachea.Thesetwolobesareconnectedbyanarrowbandcalledisthmus.Theentireglandisenclosedbyaconnectivetissuecapsule.Thisglandproduceshormone,thyroxinrichiniodine.Thyroidgetsiodinefromthebloodstream.Itisthenfixedwiththeaminoacidsthyroxincompounds.Twomolecules

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ofdiiodothyroxincombinetoformthyroxin.Thyroidstimulatinghormone(TSH)producedbytheanteriorpituitarylobeincreasestheactivityofthyroidgland.Whenever,thethyroxinlevelfallsbelowaparticularlevelTSHisstimulated.

FunctionsofThyroxin:

1) Helpstoregulatetissuegrowthanddevelopment

2) IncreasestheBMRandthusraisesthebodytemperature

3) Itcontrolsthemetabolismbyregulatingtheanabolicand

4) Catabolicprocess

5) Stimulatethecellstobreakdowntheproteinsforenergy.

6) Decreasesthebreakdownoffats

7) Increasesthebreakdownofbodyglucoseandenhancestheglucoseabsorption.

8) CalciumandPhosphorousareremovedfromthebonesandexcretedinincreasedamounts.

9) HelpsintheconversionofbetacaroteneintovitA.

ParathyroidGland

Thesearetwotinyovalpair(6mmx2mm)ofglandssituatedatupperendandlowerpolesoflaterallobesofthyroidgland.Itsecretesthehormoneparathyroxin.

FunctionsofParathyroxin:

1)Increasestheconcentrationoforganicacidinthebone.

2)Increasesthecalciumandphosphorussolubility

3)Increasesthereabsorptionofcalciumfromthebones.

4)Increasesserumcalciumlevel

5)Increasesphosphateexcretionintheurine

1

2

3

Fig2.22ThyroidGland

1)Larynx2)Thyroidgland3)Trachea

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6)Increasesthereabsorptionofcalciumfromtherenaltubules

7)Promotestheabsorptionofcalciumandphosphorusfromtheintestine.

8)Stimulatestheprocessoflactationinmammarygland.

IsletsofLangerhansinthepancreas:

Thepancreasisbothanexocrineglandsecretingdigestivejuicethroughaductintotheduodenumandanendocrineglandsecretinghormoneintothebloodstream.

Itconsistsofhead,bodyandtail.Theheadfitintothecurveofduodenum.Thenbodyandtailaredirectedtowardstheleft.Thepancreaticisletsrepresentstheendocrinepartofthepancreas.

Mostoftheisletsarelocatedinthetailandonlyasmallnumberintheheadofthepancreas.TherearetwodifferenttypesofcellsintheisletsofLangerhans.Thealphacellsandbetacellsareveryimportant.

ThealphacellssecreteahormoneGlucagonwhereasthebetacellssecreteinsulin.

FunctionsofGlucagon:

1)Increasesthebloodglucoselevel

2)Breakdowntheliverglycogenintoglucose

3)Stimulatesthebreakdownoflipidinadiposetissue

FunctionsofInsulin:

1)Convertsglucoseintoglycogenandacceleratesthetransportofglucosefromthebloodintothecells.

2)Decreasesthebloodsugarlevel

3)Builduptheglycogenstoreintheliver.

AdrenalGland:

Theadrenalorsuprarenalsaretwosmallglandseachonesituatedaboveakidney.Adrenalglandsconsistsoftwodifferentpartseachofwhichactsasaseparategland.

Theinnerareaiscalledmedullawhichisbrownincolorwhiletheouterareaiscalledcortexwhichislighterincolor

AdrenalCortex:

Itiscomposedofthreelayers.Theyare

1)Zonaglomerulosa(outerlayer)

2)ZonaFaciculate(middlelayer)

3)Zonareticularis(innerlayer)

Theadrenalcortexsecretesthreehormones.Theyare:

1.Glucocorticoids:Actsasantagoniststoinsulinandcauseincreaseinbloodsugar

2.Minerlocorticoids:Acts on sodium and potassiumand help in the conversation ofsodiuminthebody

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3.SexSteroids:Stimulatesthedevelopmentofthereproductiveorgansinthechildhood.Itisresponsiblefordevelopmentofsecondarysexcharacteristicsandreproductivefunction.

AdrenalMedulla

AdrenalMedullasecretestwohormones.Theyareadrenalineandnoradrenaline.

FunctionsofMedullaryhormones

1)Dilationofthepupilsandimprovesthevisualacuity

2)Increasesbothrateandamplitudeofcontractionofheartandraisesthecardiacoutput.

3) Increases both rate and amplitude of respiratorymovements and causes dilationofthebronchioles

4)Raisesthebloodsugarlevelbymeansofglycogenolysis

5)Increasesthebasalmetabolicrate

6)Dilationofthewallsofintestineandtheurinarybladder

Thefunctionsofadrenalinearesimilartothatofnoradrenalineexceptinafewinstances.Forexample,Adrenalinincreasestheheartratewhereasnoradrenalindecreasesheartrate.

Pituitarygland:

Thepituitaryglandisasmallglandaboutthesizeofthecherry.Itissituatedatthebaseofthebrain.Itplaysapeculiarroleinthesystemoftheendocrineglands.

Itisreferredtoasthemasterglandofinternalsecretionbecauseitcontrolstheactivitiesofotherendocrineglands.Thepituitaryglandisdividedintotwomainparts.

1) Anteriorpituitarygland.2)Posteriorpituitarygland

Theanteriorpituitarygland:Thispartsecretesalargenumberofhormones.Manyofthemstimulateotherglands.Itsmainhormonesare:

1)Growth hormone: it facilitates the growth of the bone and cartilage tissue.Overactivityoftheanteriorpituitarylobeinchildhoodresultsinexcessivegrowthandheight.Thisconditionisknownasgigantism.

Adecreasedactivityoftheanteriorpituitarycausesaseveregrowthretardationleadingtodwarfism.

Excessiveproductionofgrowthhormoneinanadultleadstoexcessivedevelopmentofcertainregionssuchasfingersandtoes,feet,hands,nose,lowerjaw,tongue,thoracicandabdominalorgans.Thisconditionisknownasacromegaly.

2.Thyrotrophicstimulatinghormone(TSH):thishormonestimulatestheactivityofthethyroidgland.Administrationofthishormonecausesovergrowthofthyroidtissue.

3.Adreniocorticotrophichormone(ACTH):thishormonestimulatesthecortexoftheadrenalglandandincreasestheproductionofthehormonesoftheadrenalcortex.

4.Follicularstimulatinghormone(FSH):thishormoneinfluencesthegrowth,developmentandmaturationandoftheovarianfollicles.Inmales,thehormonestimulatestheformationofspermintestes.

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5.Prolactinhormone:itactsonthemammaryglandandhelpsintheformationandflowofmilkduringlactation.

6.Luteinisinghormone:itisrequiredforthegrowthoffollicleintheovaryandstimulatesovulation.Intheabsenceofthehormone,noovulationandproductionofthecorpusluteumcanoccur.Inmalesitstimulatestheinterstitialcellsoftestestosecretetestosterone.

Theposteriorlobeofthepituitary:

Thislobeisjustbehindtheanteriorlobe.Itproducestwohormones.Oxytocinandvasopressin.Oxytocinactsonthesmoothmusclesespeciallythatoftheuterusandproducespowerfulcontractionsoftheuterusandhelpsinparturition.

Vasopressin acts on the smoothmuscle of the arterial system and increases the bloodpressure.Thishormonehelpsinthereabsorptionofwaterfromthedistalconvolutedtubule.VasopressindeficiencyisthecauseofdiabetesInsipidusinwhichwaterisnotreabsorbed.Sogreatamountsofurineareexcretedwithnosugarinit.Suchpatientsfeelconstantlythirsty.

Thesexglands:

Thesexglandsincludingtheovariesofthefemaleandthetestisofthemaleareimportantendocrinestructures.Thesecretionsofthisglandplayanimportantpartinthedevelopmentofthesexualcharacteristics.

Themalesexglandsecreteshormonecalledtestosteroneandisresponsibleforsecondarysexcharacteristics.Thefemalesexglandsecretesahormonecalledestrogenanditstimulatesthedevelopmentandfunctioningofthefemalereproductiveorgans.

Thereisoneotherhormoneproducedbyfemalesexglandanditiscalledprogesterone.Thishormoneassistsinthenormaldevelopmentofthepregnancy.

SENSEORGANS

Theorgansofthespecialsensearespeciallyadaptedendorgansforthereceptionofcertainkindsofstimuli.Thesensoryimpressionswhicharesuppliedbythenervescarriedtothebrainwheresensationsareinterpretedfore.g.

1)Taste 2)Smell 3)Sight4) Touch 5) Sound

Ineachcasethesensorynervesaresuppliedwithspecialnerveendingsforcollectingthestimulifortheparticularsensewithwhicheachorgandeals.Weapparentlytastewiththenerveendingsinthetongue,hearwiththoseintheearandsoon,butinrealityitisthebrainthatappreciatethesesensations.

Skin

Theskinformsaprotectiveoutercoveringaroundtheentirebody.Itconsistsofanouterthinlayercalledthe epidermis andaninnerthicklayercalledthe dermis.Numerousstructuressuchasglands,senseorgansandappendagessuchashairnailsareembeddedintheskin.

Epidermis:Thisistheoutermostthinportionoftheskin.Nobloodvesselsarefoundinthislayer.Itderivesitsnutritionfromlymph.Nervesarefoundinthislayer.Theepidermisconsistsoffourlayersofcells.

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Theyare:

1)TheStratumCorneum 2)TheStratumLucidum

3)StratumGranulosumand 4)TheStratumMalphigi

TheStratumCorneum:Thecellsinthislayerarethin,scalelike,dead,andcornified.Thecorneuslayeristhickenedinthosepartsofthebodysuchasthepalmandsoleofthefoot.Itisthinnerinthelips.Hoofs,horns,nails,feathers,thescalesofthefishesareallspecialoutgrowthsofthislayer.

TheStratumLucidum: Thisisathinmoreorlesstransparentlayer,inwhichthecellsareindistinct.

The Stratum Granulosum: It consists of three to five layers of flattened cells,containingdarkgranulesofirregularshape.

TheStratumMalphigi: Thislayeristhelowermostandbroadestlayeroftheepidermis.Itiscapableofactivemultiplication.Thislayerismadeupofpolyhedralcells.Theinnermostcellofthislayercontainspigmentgranulescalledmelaninwhichgivetheskinitscolour.

Dermis:

Situatedbelowtheepidermisisthethickestdermisformedmostlyofconnectivetissuewhichisrichlysuppliedwithbloodvesselsandnerves.

Theboundarylinebetweenthedermisandepidermisisneithersmoothnorstraightitisratherzigzagbecauseoftheconicalprojectionofthedermisintotheepidermis.

Theseprojectionsarecalled dermalpapillae.Thislayeristough,flexibleandhighlyelastic.

Itcontainsthefollowing:

1)Fineelasticfibres. 2)Capillarybloodvesselsandlymphatics.

3)Sensorynerveendingsofvarioustypes. 4)Hairrootsorhairfollicles.

5)Sweatglands. 6)Sebaceousglandsand

7)Involuntarymusclefibres.Thesemusclefibre,callederrectorespilorumareattachedtothehairfollicleandwhenthesemusclescontract,thehairsbecomeverticalandgooseskinisbroughtabout.

Glands:

Therearetwosetsofglandsintheskin.Theyare

1)TheSweatglands

2)Thesebaceousglands.

Eachsweatglandconsistsofalongtube,whichatoneendopensontothesurfacethroughthesweatspore.Attheotherends,inthedeeperpartofthedermis,thetubeformsacoiledmasswithablindend.

Inthecoiledportionofthesweatglandthereandglandularcells,whichseparatewaterandsmallquantitiesofmetabolicwasteproductsfromthebloodthatcirculatesthroughthecapillarynetworkassociatedwiththegland.

Thesweatpassesthroughthesweatporeandevaporatefromthesurfacebytakingheatfromtheskin.Thesweatglandsarepresentinlargeamountsonthepalms,soles,foreheadandinthearmpits.

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Thesebaceousglandsareirregularlyshapedsaclikeglandsthatopenintothehairfollicle.Theoilysecretions(sebum)oftheglandsmakethehair,waterproofandprotecttheskinfromdryingeffectsoftheatmosphereduetohightemperaturesandlowhumidity.

SensoryNerveEndings:

Numeroussensorynervesspecializedtopickupstimulithatcausesensationsoftouch,pressure,pain,heatandcoldarescatteredintheskin.

Theyareconnectedtothebrainbynervefibres.Stimulipickedupbythesenseorgansaretransmittedtothebrainwhentheyareinterpretedtogivethecorrectinformation.

Appendages:

Hairandnailsareappendagesoftheskinformedasaresultoftheoutgrowthorthickeningoftheepidermis.

Functionsoftheskin:

Theskinisnotmerelyanoutercoveringforthebodybutitservesavarietyoffunctions.

1)Protection:Theskinprotectstheinnerpartsofthebodyfrommechanicalinjuries.Ahealthyskinalsoprotectsthebodyfromtheinvasionofgermscausingdiseases.Thenails,hoofs,andhornsarealsodefensiveappendagesoftheskin.

2)Excretion:Likekidneys,theskinthroughitssweatglands,eliminatessalts,andmetabolicwasteproductsintheformofsweat.

3)Sensoryfunction:Thenumeroussenseorgansandnerveendingshiddenintheskinmakeitanimportantsensorystructurethatpicksupdifferentstimuliandinformsthebrainofsuchchangesintheenvironment.

4)ProductionofVitaminD:Theskincontainsasubstancecalled7dehydrocholesterolwhichisconvertedintovitaminDbyultravioletraysofthesun.

5)Regulationofthebodytemperature:Byconduction,convectionandradiationalargeamountofheatislostfromthebody.Thesubcutaneousfatandhairsactasnonconductorsofheat.Evaporationofsweattakesawayalargeamountofheatfromthebody.

6)Waterbalance:Formationandevaporationofsweatisanimportantfactorintheregulationofwaterbalanceofthebody.

7)Acidbalanceequilibrium:Sweatbeingacidinreactionagoodamountofacidisexcretedthroughit.Inacidosis,itbecomesmoreacidandinthiswayhelpstomaintainaconstantreactioninthebody.

8)Secretion:Sebumwhichissecretedbythesebaceousglandshelpstokeeptheskingreasyandpreventsdrying.Sweatissecretedbysweatgland.Milkissecretedbymammarygland.Themammaryglandsaretheskinstructures.Theyarethemodifiedsebaceousglands.

9)Storagefunction:Thesubcutaneoustissuecanstore

a.fat b.water

c.salts d.glucoseandsuchothersubstances

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Tongue

The tongue is concerned in the special sense of taste. It is a solidmuscular organ ofdeglutition,taste,speechandhelpsinmasticationoffood.Itissituatedintheoralcavity.Themucousmembraneofthetongueismoistandpinkinhealth.

Tongueconsistof3parts

Root Attachedwiththehyoidbone

Body surfaces

Apex Touchestheposteriorsurfaceoflowersurfacesincisorteeth

Surfaces:Bodycontainingdorsalsurfaceandinferiorsurface.Uppersurfacehasavelvetteappearancecoveredbythreevarietiesofpapillae

1) Circumvallatepapillae thesepapillaearearrangedinaVshapeatthebackofthetongueandtastebudsarefoundnumerousinthewallsofthecircumvallateandfungiformpapillae.

2) Fungiformpapillae aredistributedoverthelipandsidesofthetongue

3) Filiformpapillae areabundantandfoundoverthewholesurfaceofthetongueSmell:

Noseisthespecialorganofthesmellandthenasalcavitiesarelinedbymucousmembrane.Theolfactoryorfirstcranialnervesuppliestheendorgansofsmell.Thefilamentsofthenerveariseintheupperpartofthenasalcavityiscalledolfactoryportionofthenoseandlinedwithhighlyspecializedcells.

Theolfactorynervesandconnections

Theolfactorybulbisanoutlyingportionofthebrainistheslightlyenlargedportionoftheolfactorynervetractwhichliesabovethecribriformplateoftheethmoidboneformtheolfactorybulbsensationispassedalongtheolfactorytractbyseveralrelayingstationsuntilitreachesthefinalreceivingareaintheolfactorycentrewhichisinthetemporallobeofthecerebralhemispherewherethesensationisinterpreted.Thesenseofsmellisstimulatedbygasesinhaledbysmallparticle.

OrgansofspecialsenseTheearandhearing:

Theearistheorganofhearing.Thenervesupplyingthisspecialsenseistheeighthcranialorauditorynerve

Theearhasthefollowingparts

1)Externalear 2)Middleearortympaniccavity 3)Internalear.

Externalearconsistof

1)Pinnaorauriclecollectsthesoundwaves

2)Externalauditorymeatus conveysthevibrationsofsound

Middleearconsistof 1) Eardrum communicatestothemastoidprocess

2) Eustachiantube maintainingthepressureofairinthetympaniccavity

3) Auditoryossiclesare3smallbones.Theyare

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MalleusIncus Thischainofboneservestotransmitthe

vibrationsofsoundfromthedrumtotheinternalear

Stapes

Mastoidprocessisthepartofthetemporalbonelyingbehindtheearanairspacecommunicatesinthemiddleear

Internalear

Consistsofcavitiescalledthebonylabyrinthandmembranouslabyrinth.Bony

labyrinthconsistof3parts

Thevestibule It is the central part with which all the others communicate, asdoorsmayopenoutofthevestibuleofadwelling

SemicircularcanalsAssistthecerebelluminthecontroloftheequilibrium

Cochlea Spiraltubetwistedresemblingasnailshell.Thefluidwithinthemembranouslabyrinthisendolymphandthefluidinthebonylabyrinthistheperilymp.Thefenestravestbuliandthefenestracochleaarewindowsdirectedtowardsthemiddleearandallowthevibrationstransmittedtoperiandendolymphtoactivatethenerveendingsoftheauditorynerve

Hearing: Soundwavespassalongtheexternalauditorycanalcausethetympanicmembranetovibrate.Thevibrationstransmittedthroughmalleus,incusandstapes.Bymovementofthesebones,magnifythevibrations,thencommunicatedtothevestibularfenestratotheperilymphandtotheendolymphinthecanalofthecochlea.Thisstimulireachesthenerveendingsintheorganofcorti,conveyedtothebrainbyauditorynerve.Thesensationofhearingisinterpretedbythebrainasapleasantorunpleasantsound(noiseormusic).

Balance: Thechangeinthepositionofthefluidinthesemicircularcanalshelpsin ordertomaintainbalanceofthebodyandthiscanaldistributedbythevestibularnervewhichconveystothebrainthe

1)Pinna 2)Auditorycanal 3)Eardrum 4)Semicircularcanals5)AuditoryNerve 6)Cochlea 7)EustachianTube

1

2 3 4 5

6

Fig2.23Ear

7

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impulsegeneratedtherebyalterationsinthepositionofthefluidinthesecanalswhichhavetodowiththeknowledgeofthesenseofthepositionoftheheadinrelationtothebody

OrgansofspecialsenseTheeyeandsight:

Eyeballissphericalinshapesituatedintheanterior2/3oftheorbitalcavityanditisembeddedinthefatofthecavity.Theopticorsecondcranialnerveisthesensorynerveofthesight

Theeyeballcomposedof3layers 1) Outer Fibrousandsupportinglayer 2) Middle Vascular 3) Inner nervouslayer(Retina)

Fibrouslayer:

Sclera: Itisopaque,white,smoothandcontributestheposterior5/6thoftheeyeball.Itprotectsthedelicatestructureoftheeyeandhelpstomaintaintheshapeoftheeyeball

Cornea: Isatransparentfrontportion,avascularandcontinuouswiththesclera.Itconsistofseverallayersandithelpstofocusimagesontotheretina

Vascularlayer:

Choroid: Itishighlyvascularandpigmentedlayer,suppliesnutritiontotheouterlayerofretina,absorbsthelightandpreventsreflectionoflight

Ciliiarybody: Itliesbetweenthechoroidandtheirisandhascircularmusclefibersandradiatingfibershelpsinmaintainingtheaccommodationoftheeye

Iris: Itisacircular,contractileandpigmenteddiaphragm.Itisthecolorcurtaininfrontofthelensanditcontains2setsofinvoluntarymusclefibers,onesetcontractthesizeofthepupil&othersetdilatesthepupil

Pupil: Itisthedarkcentralspotwhichisanopeningintheiristhroughwhichlightreachestheretina

Nervouslayer(retina): Composedofnumberoflayersoffibers,nervecells,rodsandcones.ThemostsensitivepartoftheretinaistheMaculalies,oppositetothecentreofthepupil.Atthemiddlesideofthemaculathereisacircularpaleareawhichisinsensitivetolightcalledblindspot

1

2

34

5

6

7

Fig2.24Eye

1)Conjunctiva2)Cornea3)Iris4)Pupil5)Lens6)Retina7)OpticNerve

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Sight

Whenanimageisperceivedtheraysoflightfromtheobjectseen,passthroughthecornea,aqueoushumor,lensandvitreousbodytostimulatethenerveendingsintheretina.Thestimulireceivedbytheretinapassalongtheoptictractstothevisualareasofthebraintobeinterpreted.Bothareasreceivemessagesfrombotheyesthusgivingperspectiveandcontour.Onelensisprovidedinanordinarycamera,whereasintheeyesthecrystallinelensisimportantinfocusingtheimageontheretina

REPRODUCTIVESYSTEM

Thereproductivesystemconsistsofthoseorganswhosefunctionistoproduceanewindividual.

Maleandfemalesexualreproductiveorgans:

Thesexorgansinthemaleandfemalecanbedividedas

1. Primarysexorgansi.e.thoseproductionmaleandfemalegametes.

2. Secondary(oraccessory)sexorgansi.e.thoseconcernedwithcarriageofgametesandotherfunctions.

Primarysexorgansinmaleandfemale:

Thereareapairoftestesproducingspermatozoa(malegametes)whileinfemalesareapairofovariesproducingovum(femalegamete).Theseprimarysexorgansinadditiontoproducingmaleandfemalegametessecretemaleandfemalehormonesaswell.

Accessorysexorgansinthemale:

1. Epididymisgland

2. Vasdeferens

3. Seminalvesicles.

4. Prostrategland.

5. Urethra.

6. Penis.

Malereproductivesystem:

Thereisonepairoftesteslyingoneineachscrotalsac.Thescrotumisabagofskinhavingtwoseparatecompartments.

Oneforeachtestislyingattherootofthepenis.Eachtestisisovalshapedmeasures.5x3x2cmandweighsabout15gm.

Eachtestisiscoveredwithalayeroffibroustissuecalledtunicaalbuginea.Manyseptatefromthislayerdividethetestesintopyramidallobulesinwhichlieseminiferoustubulesandinterstitialcells.

Theseminiferoustubulesareconcernedwithprocessofspermatogenesis.TheinterstitialcellscalledLudwigcellsliebetweenthetubulesandsecretethetestosterone(malesexhormone).

Fromtheliningofthesetubulesspermatozoaareproducedbytheprocessofcelldivision.Theepididymisisaveryfineconvolutedofsurvivingformonths.

Convolutedtube,being46meterslongandjointstheposteriorpartofthetestesandvasdeferens.

Itstoresthespermatozoa.Thespermatozoaremaininactiveinepididymisandarecapableofsurvivingformonths.

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Vasdeferensisafibroelasticduct3040cminlengthandextendsfromepididymistoendinejaculatoryductwhichisjoinedbyseminalductandopensinprostaticurethra.

TheSeminalVesiclesarelittlesacsoneoneachsideoftheurethranearthebaseofthebladder.Theyreceiveandstorethespermsbroughtbythevasdeferens.Theyalsoaddafluidtothesemen.Theirductspassthroughtheprostateglandtotheurethra.

The prostrate gland lies at the base of the urinary bladder and is coveredwith fibrouscapsulewhichbyanumberofseptadividesintomanyfollicles.Theprostrateaddsanotherfluidtothesemen,whichmakesthespermsmoreactiveinswimmingtoreachtheovum.Inmiddleandoldageprostatemayenlargeandcausemicturitiontroubles.

The ejaculatory ducts lead from the seminal vesicle through the prostrate gland to theurethra.Inmalestheurethraisabout2022cminlengthandservesthepurposeofurinationaswellasejaculationofsemen.

ThePenisistheexternalorganofboththeurinaryandreproductivesystemsinthemale.Itconsistsofspongytissuewithspacesforbloodtorushintomakethepenishardanderect.Theendofthepenisiscalledtheglanspenis.Itisnormallycoveredwithaloosedoublefoldofskin(Theforeskin),whichcanbedrawnback.Theforeskincanberemovedbycircumcision.

Theurethrapassesthroughthepenisandopensattheglanspenis.

Functionsoftestis:

1) Theyproduceandmaturethemalereproductivecellscalledspermatozoa.

2) Secreteseminalfluid.

3) Secretehormonetestosteronedirectlyintotheblood.

Functionsofhormone:

1) Androgens:Maintainsspermatogenesisandsexualactivity.

2) Testosterone:stimulatesthedevelopmentofthesecondarysexualcharacteristicsofthemalesuchasthegrowthofbeard,thedeepeningofthevoice,thegrowthandthedistributionofhaironthebody,thegrowthanddevelopmentoftheaccessorysexorgans.Stimulatetheproductionofspermsatpuberty.

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3

4

5

Fig2.25MaleReproductivesystem

1)SpermDuct2)Bladder3)Prostrategland4)Penis5)Testis

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FEMALEREPRODUCTIVEORGANS

Thesearedividedintoexternalorgansandinternalorgans.

TheExternalOrgans:TheVulva

Theexternalorganstogetherformthevulva.Theyareasfollows.

MonsvenerisorpubicMont:itliesoverthesymphysispubis,andiscoveredwithhairafterpuberty.

Labiamajoraortheouter lips,formthesidesofthevulva.

Labiaminora,orsmallerlips,arewithinthelabiamajora.Theyaremoistbyglandsecretions.

Clitoris asmallsensitiveorganwitherectiletissuesimilartothemalepenis.

Vestibule: atriangularpartbetweenhelabiaminora.Theurethralopeningisinthevestibuleinfrontofthevaginalopening.

Vagina: Itisamusculartubelinedwithmembranecomprisedofspecialtypeofstratifiedepithelium,wellsuppliedwithbloodvesselsandnerves.Itextendsfromthevestibuletotheuterus.

Perineum:Thisistheareaoftheskinfromthevaginalopeningbacktotheanus.Itcoverstheperinealbody,whichisawedgeshapedstructurebetweenthevaginaandlowerpartoftherectum.Themuscleoftheperinealbodyformsthemainmuscleofthepelvicfloor.Itflattensduringthesecondstageoflabourandquiteoftengetstorn.

Femalereproductiveinternalorgans:

Theinternalorgans,whicharesituatedinthepelvis,areasfollows:

1) Fallopiantubes 2)Uterus

3) Vagina 4)Ovaries

Fallopiuantubes: thefallopiantubesaretwothintubesconnectedtothesidesoftheuterus,justbelowthefundus.eachtubeisabout10cmlong,curvesbackwardsbehindtheuterusandaroundtheovarylikeanarch.theouterendwidensandopensintotheperitonealcavity.Thisopeningissurroundedbyfingerlikeprocessescalledfimbriae,oneofwhichisconnectedtotheovary.Thefallopiantubeshavewallsofmuscleandarelinedwithciliatdepitheliumandcoveredwithperitoneum.

Fig2.26FemaleExternalOrgans

1)Clitoris 2)Urethra 3)Vagina 4)Anus5)LabiaMajora 6)LabiaMinora

5

6

1

23

4

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Functions:

Thesetubesactasductsforthefemalegametesalthoughtheyarenotconnectedtotheovaries.Thefunctionofthetubeistocollecttheovumdischargedfromovaryandpassitalongthetube.Itissentalong partly by peristaltic act ion of the muscles and partly by wavingmovementsofthecilia.Fertilizationofthemaleandfemalegametesnormallyoccursinthetubesattheampullaryportion.

Uterus:Uterusisapearshapedmuscularorgan.Thisinsideofwhichishollow.Itmeasuresabout7.5x5x2.5cmandweighsabout60gm.consistsofanupperportioncalledthebodyandthelowerportioncalledthecervix.Theuterusislinedbyamucusmembraneknownastheendometrium.Theuterushasthreeparts:

1)Fundus,theupperpartbetweeenthetwofallopiantubes.

2)Body,themiddlepart,whichhasatriangularshapedcavity.

3)Cervix,thelowernarrowpart,whichprojectsintothevaginabelow.Thecervixisabout2.5cmlong,andhasacentralcanalwithtwocircularopenings:theinternaloswhereitjoinswiththebodyoftheuterus,andtheexternalos,whichopensintothevagina.

Thewalloftheuterusisinthreelayers:

1)Perimetrium,theouterserouslayer.

2)Myometrium,themuscularlayer,whichisthickandstrong.

3)Endometrium,theinnerliningofspecialepithelialtissue.Thenarrowcavityoftheuterushasthreeopenings:oneintoeachfallopiantube,andonethroughtheexternalosofthecervixintothevagina.

Functions

1)Menstruationthethickenedendometriumcomesawaycausingbleedingoftornvessels,andtheresultingmenstrualflowisdischargedthroughthevagina.

Fig2.27TheUterus

1)Fallopiantube 2)Fundus 3)DevelopingEgg 4)Myometrium5)BodyoftheUterus 6)Ovary 7)Cervicalcanal 8)Vaginalcanal

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1 2

34

57

8

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2)Pregnancytheuterusreceivesthefertilisedovumandnourishesthedevelopingfoetus.

3)Labourcontractionsofthemuscularwallcausethefoetusandplacentatobeexpelled.

4)Involutionthegradualreturntonormalsizeoftheuterusfollowingdelivery.

Ovary:

Thegonadso