Anatomy of heart

Anatomy of Heart

1. ANATOMY OF HEART
Mr.BinuBabu
MBA, M.Sc. (N)
Asst. Professor
Mrs. JincyEalias
M.Sc. (N)
Lecturer

2. Heart
•Theheartisahollow,cone-shaped,muscularpump.
Theheartbeatsabout2.5billiontimesinanaverage
lifetime.
•Theleftsideoftheheartpumpsbloodthroughan
estimated120,000kmofbloodvessels,whichis
equivalenttotravelingaroundtheearth’sequator
about3times.
•Therightsideoftheheartpumpsbloodthroughthe
lungs,enablingbloodtopickupoxygenandunload
carbondioxide.Heartpumpsmorethanabout
14,000litersofbloodinaday,or5millionlitersina
year

3. Dimensions of Heart
•TheheartisasmallOrgan,itisabout12cm
(5in.)long,9cm(3.5in.)wideatitsbroadest
point,and6cm(2.5in.)thick,withan
averagemassof250ginadultfemalesand
300ginadultmales.
•Theheartrestsonthediaphragm,nearthe
midlineofthethoraciccavity.

4. •Theheartliesinthemediastinuman
anatomicalregionthatextendsfromthe
sternumtothevertebralcolumn,fromthe
firstribtothediaphragm,andbetweenthe
lungs

5. Relations of Heart
•Superiorly–theaorta,superiorvenacava,
Parteryandpulmonaryvein.
•Inferiorly–thediaphragm
•Anteriorly–theribsandintercostal
muscles.
•Posteriorly–theesophagus,trachea,left
andrightbronchus,descendingaorta,
inferiorvenacavaandthoracicvertebrae
•Laterally–thelungs

7. •Thepointedapexisformedbythetipofthe
leftventricleandrestsonthediaphragm.It
isdirectedanteriorly,inferiorly,andtothe
left.
•Thebaseoftheheartisitsposterior
surface.Itisformedbytheatriaoftheheart.

8. Surfaces
•The sternocostalor anterior surface is
deep to the sternum and ribs.
•The diaphragmatic or inferior surface is
the part of the heart between the apex and
right border.
•The pulmonary or left surface is occupies
the cardiac notch of the left lung.

10. Boarders
•Therightborderisformedbyrightatrium
anditfacestherightlungandextendsfromthe
inferiorsurfacetothebase.
•Theinferiorborderisformedbyright
ventricleandpartlyleftventricle.
•Theleftborderalsocalledthepulmonary
border,isformedbyleftventricleandtheleft
auricleanditfacestheleftlungandextends
fromthebasetotheapex.
•Thesuperiorborderisformedbybothatria.

12. Sulci of Heart
Itisagrooveontheoutersurfaceoftheheart
markingthedivisionbetweentheatriaand
theventricles.
1.Atrioventricular sulcus
2.Anterior interventricular sulcus
3.Posterior interventricular sulcus

14. •Atrioventricularsulcus:Separatesatria
fromventricles,itcontainsrightcoronary
artery,leftcoronaryartery,circumflexartery,
coronarysinus.
•Anteriorinterventricularsulcus:lies
betweenleftventricleandrightventricleon
theanteriorsurface,markslocationof
interventricularseptumcontainsleftanterior
descendingartery,greatcardiacvein.
•Posteriorinterventricularsulcus:lies
betweenleftventricleandrightventricleon
posteriorsurface,containsposterior
interventriculararteryandmiddlecardiac
vein

15. Pericardial Sinuses
•Thelinesofreflectionbetweenvisceraland
parietalpericardiumformtwopericardial
sinuses
a.Thetransversepericardialsinuslies
anteriortothesuperiorvenacavaand
posteriortotheascendingaortaand
pulmonarytrunk.
b.Theobliquepericardialsinusliesposterior
totheheartinthepericardialsac.

16. The transverse pericardial sinusThe oblique pericardial sinus

17. Anterior Surface of heart

18. AURICLE
•Anteriorsurfaceofeachatriumisa
wrinkledpouchlikestructurecalledan
auricle.Eachauricleslightlyincreasesthe
capacityofanatriumsothatitcanholda
greatervolumeofblood.

19. Posterior Surface of Heart

20. Coverings of the Heart
Pericardium
•The heart is enclosed in a double-walled sac called
the pericardium
•It consists of two main parts:
1.The fibrous pericardium
2.The serous pericardium
•Thefibrous pericardium is composed of tough, inelastic,
dense irregular connective tissue. The functions of fibrous
pericardium is to
1.Preventoverstretching of the heart
2.Protection of heart
3.Anchors the heart in the mediastinum

21. Relationship of serous pericardium
to heart

22. •Theserouspericardiumisathinnermembrane
thatformsadoublelayeraroundtheheart
–Theouterparietallayer:itisfusedtothe
fibrouspericardium.
–Theinnerviscerallayerisalsocalledthe
epicardiumhelpsthelayersoftheheartwallto
adherestightlytothesurfaceoftheheart.

23. The pericardial layers and layers of
the heart wall.

24. •Aslipperyfluidispresentinbetweenthe
parietalandviscerallayershelpstogive
lubricationandreducesfrictionwhilethe
heartbeatsisthepericardialfluid.
•Thespacebetweenthetwolayersarecalled
thepericardialcavity.

25. Layers of the Heart Wall
The wall of the heart
consists of three layers
–The epicardium
(external layer)
–The myocardium
(middle layer)
–The endocardium
(inner layer)

26. Epicardium
•Itisathintransparentouterlayeroftheheartwall
iscomposedofmesothelium(membrane
composedofsimplesquamouscells)
•Theepicardiumcontainsbloodvessels,
lymphatics,andvesselsthatsupplythe
myocardium.

27. Myocardium
•Themyocardiumisresponsibleforthe
pumpingactionoftheheartandiscomposedof
cardiacmuscletissue.Themusclefibersare
wrappedandbundledwithconnectivetissue
sheathscomposedofendomysiumand
perimysium.
•Thecardiacmusclefibersareorganizedin
bundlesthatswirldiagonallyaroundtheheart
andgeneratethestrongpumpingactionsofthe
heart

29. Circular and spiral arrangement
of cardiac muscle

30. Endocardium
•Theendocardiumisaglisteningwhitesheet
ofendothelium(squamousepithelium)
restingonathinconnectivetissuelayer.
•Itlinestheheartchambersandcoversthe
fibrousskeletonofthevalves.
•Theendocardiumiscontinuouswiththe
endothelialliningsofthebloodvessels
leavingandenteringtheheart.

31. Chambers of the Heart
•Thehearthasfourchambers.Thetwo
superiorreceivingchambersaretheatria
andthetwoinferiorpumpingchambersare
theventricles

33. Right Atrium
•Therightatriumformstherightborderoftheheart
andreceivesbloodfromthreeveins:thesuperiorvena
cava,inferiorvenacava,andcoronarysinus.Theright
atriumisabout2–3mm(0.08–0.12in.)inthickness.
•Theposteriorwallissmoothbuttheanteriorwallis
roughduetothepresenceofmuscularridgescalled
pectinatemuscles
•Therightatriumandleftatriumisseparatedby
interatrialseptum.Aprominentfeatureofthis
septumisanovaldepressioncalledthefossaovalis.
•Bloodpassesfromtherightatriumintotheright
ventriclethroughavalvethatiscalledthetricuspid
valve,itconsistsofthreeleafletsorcusps.

35. •Thecuspsofthetricuspidvalveare
connectedtotendonlikecords,thechordae
tendineaewhichinturnareconnectedto
cone-shapedtrabeculaecarneaecalled
papillarymuscles.

36. Right Ventricle
•Therightventricleisabout4–5mm(0.16–0.2in.)inaverage
thicknessandformsmostoftheanteriorsurfaceoftheheart.
•Therightventriclecontainsaseriesofridgesformedby
bundlesofcardiacmusclefiberscalledtrabeculaecarneae,it
helpstheheartforconduction.
•Therightventricleisseparatedfromtheleftventriclebythe
interventricularseptum.
•Bloodpassesfromtherightventriclethroughthepulmonary
valveintoalargearterycalledthepulmonarytrunk,which
dividesintorightandleftpulmonaryarteries

38. LeftAtrium
•Theleftatriumisaboutthesamethicknessas
therightatriumandformsmostofthebaseof
theheart.
•Itreceivesbloodfromthelungsthroughfour
pulmonaryveins.Ithasasmoothanteriorand
posteriorwall,becausepectinatemusclesare
confinedtotheauricleoftheleftatrium.
•Bloodpassesfromtheleftatriumintotheleft
ventriclethroughthebicuspid(mitral)valve
Itisalsocalledtheleftatrioventricularvalve.

40. Left ventricle
Theleftventricleisthethickestchamberoftheheart,
averaging10–15mm(0.4–0.6in.)andformstheapexofthe
heart.
Liketherightventricle,theleftventriclecontainstrabeculae
carneaeandhaschordaetendineaethatanchorthecuspsof
thebicuspidvalvetopapillarymuscles.
Bloodpassesfromtheleftventriclethroughtheaorticvalve
(aorticsemilunarvalve)intotheascendingaortafromhere
bloodflowsintothecoronaryarteries,whichbranchfromthe
ascendingaortaandcarrybloodtotheheartwall.
Theremainderofthebloodpassesintothearchoftheaorta
anddescendingaorta(thoracicaortaandabdominalaorta).
Branchesofthearchoftheaortaanddescendingaortacarry
bloodthroughoutthebody.

42. Comparison of right and left atrium
Right atrium left atrium
1Receivesvenousbloodfrombody. 1ReceivesoxygenatedbloodfromLung.
2PushesbloodtoRtventriclethrough
tricuspidvalve.
2PushesbloodtoLtventriclethrough
bicuspidvalve.
3FormsRtboarder,partsof
sternocoastalandsmallpartofbaseof
theheart
3Formsmajorpartoftheheartbase
Comparison of right and left ventricle
Right Ventricle left Right Ventricle
1Thin 1Thicker
2Pushesbloodonlytothelung 2Pushesbloodtoentirebodyexcept
lung
3Containsthreepapillarymuscles 3Containstwopapillarymuscles
4Cavityiscrescentic 4Cavityiscircular
5Containsdeoxygenatedblood 5Containsoxygenatedblood
6Formssternocoastalsurface 6Formsdiaphragmaticsurface

43. Valves of Heart

44. The Tricuspid Valve
•Thetricuspidvalveconsistsofthreecusps
anterior,septalandinferior(posterior).
Thesecuspsareformedbyafoldofthe
endocardiumandsomeconnectivetissue.
Thebasesofthecuspsattachtothefibrous
ringoftheheartskeletonandtheirfree
edgesattachtothechordaetendineae
connectingthemtothepapillarymuscles.

46. The Mitral Valve
•Themitralvalveconsistsoftwocusps
anteriorandposterior:itsstructureis
similartothetricuspidvalve.Theanterior
cuspislargerandintervenesbetweenthe
atrioventricularandtheaorticorifices.The
chordaetendineaeattachthecuspsto
papillarymusclesasinthetricuspidvalve.

48. The Pulmonary Valve
•Itconsistsofthreesemilunarcuspsformedby
foldsoftheendocardiumandsomeconnective
tissue.Thelowermarginsofthecuspsand
theirsidesareattachedtothearterialwall.
•Thepulmonaryvalvehasthreecusps:the
anteriorcusp(AC),theleftcusp(LC),andthe
rightcusp(RC).
•Therearenochordaetendineaeorpapillary
musclesattachedtothesevalves.

50. The Aortic Valve
•Thevalvesarearrangedasoneanterior(right)
andtwoposterior(leftandposterior).
•Theaorticvalvehasthreecusps:theleft
coronarycusp(LCC),therightcoronarycusp
(RCC),andthenon-coronarycusp(NCC).
•Therightcoronaryarteryoriginatesfromthe
anterioraorticsinusandtheleftcoronary
arteryfromtheleftposteriorsinus.

52. Blood supply to the heart
ArterialSupply
•Thefirsttwobranchesoftheaorta,calledtherightand
leftcoronaryarteries,supplybloodtothetissuesofthe
heart.
•The left coronary artery runs toward the left side of
the heart and then divides into two major branches:
–The anterior interventricularartery follows the anterior
interventricularsulcusand supplies blood to the
interventricularseptum and anterior walls of both ventricles.
–The circumflex artery supplies the left atrium and the
posterior walls of the left ventricle.

53. •Therightcoronaryarterycoursestothe
rightsideoftheheart,ithastwobranches:
–Therightmarginalarterysupplybloodtothe
lateralrightsideofmyocardium.
–Theposteriorinterventriculararterysupplies
bloodtotheposteriorventricularwallsand
merges(anastomoses)withtheanterior
interventricularartery.

55. CoronaryVeins
•Thevenousbloodiscollectedbythecardiacveins.These
veinsjointoformanenlargedvesselcalledthecoronary
sinus,whichemptiesthebloodintotherightatrium.
•Theprincipaltributariescarryingbloodintothecoronary
sinusarethefollowing:
1.Greatcardiacveinintheanteriorinterventricularsulcus,
whichdrainstheareasoftheheartsuppliedbytheleftcoronary
artery(leftandrightventriclesandleftatrium)
2.Middlecardiacveinintheposteriorinterventricularsulcus,
whichdrainstheareassuppliedbytheposteriorinterventricular
branchoftherightcoronaryartery(leftandrightventricles)
3.Smallcardiacveininthecoronarysulcus,whichdrainsthe
rightatriumandrightventricle
4.Anteriorcardiacveins,whichdraintherightventricleand
opendirectlyintotherightatrium

57. Nerve supply to the heart
•Thecardiacnervesarebranchedautonomicnervefibers
andarefoundatthelevelofthetrachealbifurcation.
•Theirfunctionistoinnervatetheelectricalconducting
systemoftheheart,theatrialand
ventricularmyocardiumandthecoronaryvasculature.
•Themedullaistheprimarysiteinthebrainfor
regulatingsympatheticandparasympatheticoutflowto
theheartandbloodvessels.
•Thehypothalamusandhighercentersmodifythe
activityofthemedullarycentersandareparticularly
importantinregulatingcardiovascularresponsesto
emotionandstress(eg,exercise,thermalstress).

59. The Sympathetic Nerve actions
•Thesympatheticfibersstemfromthe
intermediolateralcellcolumnofthethoraciccords
T1toT4beforemergingintothesympathetictrunk.
•Thepreganglionicfiberssynapseinthesympathetic
gangliaofthecervicalandthoracicregions,whichin
turnpassonpostganglionicfiberstothecardiac
plexus.
•Sympatheticinnervationdirectlyopposesthe
parasympatheticsystembyincreasingtheheart
rate,cardiaccontractionsandconstrictingthe
coronaryresistancevessels.

61. Parasympathetic Nerve Actions
•Theparasympatheticfibersarecontributed
bythevagusnerve(CNX)andareclassedas
preganglionicfibers.
•Theirroleduringinnervationistodecrease
theheartrate,todecreasetheforceof
cardiaccontractionsandtodilatethe
coronaryresistancevessels.
•Mostofthevagaleffectsarelimitedtothe
areaaroundthesinoatrialnode.

63. Cardiac muscle fibers
•Cardiacmusclefibersareshorterinlengthandlesscircular
intransversesection.Thebranchingcardiacmusclefibers
producea“stair-step”appearance.
•Acardiacmusclefiberis50–100μmlongandhasa
diameterofabout14μmandonecentrallylocatednucleus.
•Thecardiacmuscletogetherbyirregulartransverse
thickeningsofthesarcolemmacalledintercalateddiscs.
•Thediscscontaindesmosomes,whichholdthefibers
together,gapjunctions,whichallowmuscleaction
potentialstoconductfromonemusclefibertoother.
•Thisgapjunctionsallowtheentiremyocardiumoftheatria
ortheventriclestocontractasasingle,coordinatedunit.

65. •Cardiacmusclefibershavethesame
arrangementofactinandmyosin,andthe
samebands,zones,andZdiscs,asskeletal
musclefibers.

67. Applied Anatomy
X-ray(Radiography)-Chest
•Chestx-rayusesaverysmalldoseofionizing
radiationtoproducepicturesoftheinsideof
thechest.
•Itisusedtoevaluatethelungs,heartandchest
wallandmaybeusedtohelpdiagnose
shortnessofbreath,persistentcough,fever,
chestpainorinjury.Italsomaybeusedtohelp
diagnoseandmonitortreatmentforavariety
oflungconditionssuchaspneumonia,
emphysemaandcancer.

69. Coronaryangiography
•Coronaryangiographyisaprocedurethat
usesaspecialdye(contrastmaterial)andx-
raystoseebloodflowsthroughthearteries
inheart.Thedyehelpstohighlight
blockagesinbloodflow.