its about the whole circulatory system of a typical human.

1. CIRCULATORY SYSTEM CONSISTS OF
THE HEART, BLOOD VESSELS, WHICH
TOGETHER MAINTAIN A
CONTINUOUS FLOW OF BLOOD
AROUND THE BODY.
CIRCULATORY SYSTEM

2. Structure of heart
Heartis a hollow, fibro muscular organ.
It is slightly conical or pyramidal in shape.
Membrane that protects&surrounds the heart is calledpericardium
pericardial cells secretes a fluidtermedpericardial fluid
Pericardial fluidis presentin the pericardial cavity.

3. WALL OF THE HEART IS DIVIDED INTO 3 LAYERS THEY ARE,

4. LOCATION OF HEART
Heart liesbetween the lungs in the middleof mediastinum
It is enclosed in pericardium
It is obliquelyin the chest behind the sternumand adjoining parts of ribs.
Pericardiumis of 2layerstheyare:
Serous pericardium
Fibrous pericardium

5. HEART
PERICARDIAL
CAVITY
SEROUS
PERICARDIU
M
VISERAL
LAYER
OF
SEROUS
PERICARDIUM
PARIETAL
LAYER OF
SEROUS
PERICARDIUM

6. LOCATION OF HEART
Ribs
lungsHeart in
mediastinum

7. SIZE OF HEART
Adult heart’s length-12 cm
breadth-8 to9 cm
thickness-6 cm
Male’s heart weighsabout 280 to 340 gms
Female’s heartweighsabout230 to280 gms
Increase in weight and size up to advanced period of life ,increased more
marked in menthanin women.

8. CHAMBERS OF HEART
RIGHT
ATRIUM
LEFT
ATRIUM
RIGHT
VENTRICLE
LEFT
VENTRICLE

10. RIGHT ATRIUM
Formsright border of heart, it receives bloodfrom3 veins, superior &
inferior venecava and coronary sinus.
it is about 2-3mm(0.08-0.12 in)in thickness.it is larger than left.
Posteriorwallis smooth, while the anterior wall is rough because of the
presenceof pectinatemuscle(muscularridges).

11. LEFT ATRIUM
It hassame thicknessas right atrium, also it formsthe baseof theheart.
It receivesblood fromthe lungs through 4 pulmonary veins .
As the right atrium,inside it has smoothposterior wall,
The anteriorwallof left atriumis also smooth.
It is smallerthanright but have thicker wall.

12. RIGHT VENTRICLE
It is about 4-5mm(0.16-0.2 in)in average thickness.itswall is thinner
thanthat of left.
It formsthe anteriorsurface of the heart.
Inside of the right ventriclecontains a series of ridges formed by raised
bundlesof cardiac muscle fibers called trabeculae carnae.

13. LEFT VENTRICLE
It is thethickest chamberof theheart averaging 10-15mm(0.4-
0.6in).
it formsthe apex of the heart.
Like the right ventricle,left ventriclealso contains trabeculaecarnea.

14. VALVES OF THE HEART
Valves in the heart
opens and closes in
response to the
pressure changes as
the heart contracts
and relaxes .
Valves ensures the 1
way flow of blood.
There are 4 valves
present .they are,
• Aortic valve
• Pulmonary valve
• Tricuspid valve
• Bicuspid valve

15. Pulmonary valve
Aortic valve
Tricuspid valve
Bicuspid valve
Superior view of
valves

16. Aortic &pulmonary valve.
Bloodpasses fromthe left ventricle throughaortic
valve
intothe ascending aorta.
Bloodpasses fromthe right ventricle through
pulmonaryvalve intoa large artery called the
pulmonarytrunk,which divides into pulmonary
arteries.
Generallyarteries take blood awayfromthe heart
Superior view of aortic valve

17. TRICUSPID VALVE
Bloodpassesfromthe right
atriumto right ventricle
through a valvethat is called
tricuspidvalve.
Becauseit consistof 3 cusps or leaflets.

18. bicuspid valve
it is otherwisetermedas mitral valve.
Blood passesfromleft atriuminto left ventricle
throughbicuspidvalve, name implies the 2 cusps.
Bicuspid valve open Bicuspid valve closed

19. Pulmonary &aortic valves
closed. others 2 open.
Bicuspid &tricuspid
valves are closed ,
other 2 open

20. STRUCTURE OF BLOOD VESSELS.
Blood vesselsformsa
closed systemof tubesthat
carryblood awayfromthe
heart, transport it the
tissues,& thenreturn to the
heart.
Thereare various
typesof vessels.

21. TYPES OF BLOOD VESELS
Arteries
Arterioles
Capillaries
Venules
Veins
Vasa
vasorum

22. ARTERIES
Wall of artery has 3 major layers .
TUNICA
INTERNA(INTIMA),TUNI
CA MEDIA,TUNICA
EXTERNA.
There are 2 types of arteries,
Muscular
arteries(DISTRIBUTION
ARTERIES)
Elastic
arteries(CONDUCTING
ARTERIES)
Tunica externa
Tunica interna
Lumen
with blood
vessels
Tunica media

23. ARTERIOLES
Theseare verysmall , almostmicroscopic arteriesthat deliverbloodto
capillaries. itsdiameteris 15-300micrometer.
Throughvasoconstriction & vasodilation, arterioles assumes a key role in
regulating bloodflowfromarteriesintocapillaries&in altering arterial blood
pressure.
Metaarteriolesformbranchesintocapillary bed.

24. CAPILLARIES
Theseare microscopicvessel that connect arteriolesto venules.size-5-10micro
meterin diameter.
Found neareverycell in the body but more extensive in highlyactive
tissue.(e.g.: kidney, liver)
Thereare 3 typesof capillaries-continuous, fenestrated, sinusoids capillaries.
Lacking in epithelia ,cornea , lens of eye , cartilage.
Its wall is composedof only a singlelayer of cell & a basement membrane.

25. Continuous
capillary
Fenestrated
capillary
sinusoid
TYPES OF CAPILLARIES

26. Endothelium
Basement membrane
Smooth muscle
TUNICA EXTERNA
TUNICA MEDIA
TUNICA INTERNA
Basement membrane
Lumen
Endothelium
ARTERY
VEIN
CAPILLARY

27. VENULES
Small veinscollecting blood formcapillaries.
Tunica media containsonlya fewsmooth musclecells& scattered fibroblast
Very porousendotheliumallowsforescapeand many phagocytic whiteblood
cells.
Venulesthat approaches sizeof veins more closely resemblestructureof veins.

28. VEINS
Veins consistsof same 3 tunicsas arteries ,but have a
thinner tunicsas arteries, but have a thinner tunica
interna & media ,thicker externa.
It has less elastic tissue & smoothmuscle .
It has thinner wall thanartery.
It size-ranges from0.5mm-3cmin diameter.
Valves are thinfolds of tunica interna designedto prevent
backflow.

29. VASa VASORUM
Vasavasorumare small bloodvessels
that supplyblood to the cellsof the
wallsof arteries, veins.
Vasa vasorum

30. SYSTEMIC CIRCULATION
It is left side heart to thebody &backto theheart.
It takesoxygenated blood fromleft ventriclethrough aortato all partsof body
, including somelung tissue & returns the deoxygenatedblood to right
atrium.
Bloodreturnsto heartthrough systemicvein.
All the veins of this circulationflows into superior, inferiorvenae,whichin
turn empty intothe right atrium.

32. PULMONARY CIRCULATION.
It takesdeoxygenatedbloodfromthe right ventricleto the air sacsof the
lungs &returnsoxygenated blood fromthe lungs to left atrium, vessels
include –pulmonary trunk , arteries , veins.
Bloodis not pumpedso far as in systemic.
Resistance to blood flowis verylow meaning that less pressure is need to more
blood throughlungsin pulmonary circulation.

35. PORTAL CIRCULATION.
In systemic circulation,the venousblood passing through spleen, pancreas,
stomach, intestineis not carried back directlyto heart.
It is the subdivisionof the systemic circulation.
It passesthrough hepatic portal veinto liver .
Thisveinbeginsas capillariesfromvisceral organs&endsin liveragainas
capillaries.
It enablesliverto acquire nutrients utilization& blood detoxification.

38. CORONARY CIRCULATION
Nutrientsare notable to diffusesquicklyenough fromblood in the chambers
of the heart to supplyall the layers of cellsthat make up heart wall.
For thismyocardiumhas its own network of blood vesselsthe coronary
/cardiac circulation.
The coronaryarteriesbranchfromthe ascending aorta& encircle the heart .

40. THANK
YOU
PRESENTED BY,
PAVITHRA DEVI.V
DEPT.OF
.BIOMEDICAL SCIENCE