The pericardium is the sac that encloses the heart. It consists of an outer fibrous part known as the fibrous pericardium, and a double layered serous sac known as the serous pericardium. The pericardium prevents sudden dilatation of the heart, especially the right chamber, and displacement of the heart and great vessels, minimizes friction between the heart and surrounding structures, and prevents the spread of infection or cancer from the lung or pleura.

1. ANATOMY OF THE
HEART
Dr. NDAYISABA CORNEILLE
CEO of CHG
MBChB,DCM,BCSIT,CCNA
Supported BY

2. THE PERICARDIUM
• The pericardium is the sac that encloses
the heart. It consists of an outer fibrous
part known as the fibrous pericardium,
and a double layered serous sac known as
the serous pericardium.
• The pericardium prevents
– sudden dilatation of the heart, especially the right
chamber, and displacement of the heart and great
vessels,
– minimizes friction between the heart and
surrounding structures, and
– prevents the spread of infection or cancer from the
lung or pleura.
Dr Ndayisaba Corneille

3. The fibrous pericardium
• The fibrous pericardium
servers to limit the
sudden distention of the
heart, it is conical in
shape and has an apex
and a base, anterior and
a posterior surface.
Dr Ndayisaba Corneille

4. The serous pericardium
• The serous pericardium has both a parietal layer and a visceral layer. The parietal
layer lines the inside of the fibrous pericardium while the visceral layer lines the
heart and the vessels entering it.
• This layer is also known as the epicardium of the heart. The serous pericardium
gives rise to two sheaths – A venous serous sheath and arterial serous sheath.
Dr Ndayisaba Corneille

5. CONTENTS OF THE PERICARDIUM
• Pulmonary trunk
• Ascending aorta
• Terminal ends of
inferior vena cava and
• superior vena cava
• Right and left
pulmonary veins
• The heart.
Dr Ndayisaba Corneille

6. BLOOD SUPPLY, NERVE SUPPLY
• Blood is supplied by branches
from the internal thoracic
artery, and musculophrenic
artery and from the descending
aorta.
• Its venous drainage is from
tributaries that empty into the
azygous system of veins.
• It is supplied by branches
arising from the vagus, phrenic
and sympathetic trunk.
Dr Ndayisaba Corneille

7. APPLIED ANATOMY: Pericardial effusion
• The potential space between the
parietal and visceral layers of the s
erous pericardium normally contain
s a small volume of fluid.
• Excess fluid is
termed a pericardial effusion. If t
he volume is sufficiently large, this
can reduce ventricular filling as a
consequence of the lack of elasticity
of the fibrous pericardium and this is
termed
• cardiac tamponade. In severe cases
, this can cause heart failure.
Dr Ndayisaba Corneille

8. Cardiac Tamponade
– Cardiac enlargement or chronic
pericardial effusions, both of
which develop slowly, will stretch
the fibrous pericardium.
– However, the fibrous pericardium
cannot stretch acutely, and the
rapid accumulation of as little as
200 mL of fluid can result to fatal
cardiac tamponade.
Dr Ndayisaba Corneille

9. Pericardiocentesis and Pericardial
puncture
• pericardiocentesis is the
drainage of the excess fluid through insertion of
a needle as
may be required to alleviate tamponade.
• Pericardial puncture is carried out close to the
medial or sternal end of the right 5th to 6th costal
cartilage near the margin of the sternum
(Parasternal) to avoid puncture of the internal
thoracic artery. It can also be made close to the
xyphoid process i.e. left xiphicostal angle
(Substernal); the syringe is passed upwards and
backwards to enter the pericardium.
• Hemopericardium results from perforation of either
the heart or the intrapericardial great vessels
Dr Ndayisaba Corneille

10. Epicardial deposit of fat
• In obese subjects,
excessive epicardial
deposit of fat may
encase the heart, but
because pericardial fat
is liquid at body
temperature, cardiac
motion is generally
unhindered
Dr Ndayisaba Corneille

11. THE HEART
A human heart viewed from
the so-called anterior
position, demonstrating the
valentine heart orientation.
The red line surrounding
the heart is the
characteristic symbol,
which was theoretically
derived from observing the
heart in this orientation
.

12. Dr Ndayisaba Corneille
External Heart: Anterior View
Figure 18.4b

13. THE HEART
• The heart is a pair of muscular
pump with valves that is combined
into a single organ.
• Although it is composed of a
fibromuscular skeleton and
conducting tissues that are
structurally interwoven, they are
functionally i.e physiologically
differentiated into right & left parts.
Dr Ndayisaba Corneille

14. DEVELOPMENT OF THE HEART
• The heart starts developing from
the 3rd week of intrauterine life.
• By the formation of two parallel
cardiogenic cords.
• The cords become canalized to
form two endothelial tubes
referred to as endocardial heart
tubes.
Dr Ndayisaba Corneille

15. • the two heart tubes will fuse together to form a
tubular vessel with one chamber. Which is
attached to the dorsal wall by a dorsal mesentery
known as Mesocardia.
Dr Ndayisaba Corneille

16. As the heart develops it later
forms 5 saculations known as:-
Truncus Arteriosus, Bulbos
Cordis, Primitive ventricle,
Primitive Atrium, and Sinus
Venosus
Dr Ndayisaba Corneille

17. • As the heart increases in length its mesocardia does not allow it
to grow upwards out of the future pericardial sac and so
developing heart begins to form an S - shaped tube.
• Its two caudal segments the sinus venosus and primitive Atrium
comes to lie dorsal to the three cephalic segments.
Dr Ndayisaba Corneille

18. • The truncus arteriosus
divides to form the
ascending aorta and the
pulmonary trunk.
• A definite ventricle is
formed from the bulbus
cordis and primitive
ventricle,
Dr Ndayisaba Corneille

19. • while the definite Right Atrium are
formed from the right half of the
primitive atrium and the right half
of the sinus venosus.
• Actually the left half of the sinus
venosus disintegrates.
• Therefore the left atrium is formed
from the left half of the primitive
atrium and the developing
pulmonary veins.
Dr Ndayisaba Corneille

20. • The 2 atria lies
posterior while the
two ventricles lie
anterior but later the
heart will undergo a
slight rotation to the
left and on its long axis
and so the following
events occurs.
Dr Ndayisaba Corneille

21. • The right atrium is now largely
anterior partly posterior
forming the right border
• The left atrium comes to lie
posterior
• The right ventricle comes to lie
largely in front and slightly
inferior.
• The left ventricle comes to lie
largely inferior and slightly in
front forming the apex of the
heart and the left border.
• The interatrial and
interventricular septa comes to
face forward.
Dr Ndayisaba Corneille

22. THE ADULT HEART
• The heart is conical
in shape, and
possess an apex
and four surfaces.
Which include
– the base
(posterior surface)
– a sternocostal
(anterior surface)
– a left Surface
– and a
diaphragmatic
surface (inferior
surface). Dr Ndayisaba Corneille

23. • Location
• The Heart is situated in
the mediastinum of the
thoracic cavity, enclosed
in the pericardium.
• It is somewhat pyramidal
in shape and placed
obliquely behind the
sternum so that 1/3rd of
the heart is to the right of
median plane and 2/3rd of
the heart is to the left of
the median plane.
Dr Ndayisaba Corneille

24. In infants the heart is
about 1/130 of the body
weight while in adult it is
about 1/300 of body
weight. Therefore the
heart is relatively larger in
infants than in adults.
Dr Ndayisaba Corneille

25. The Base
• The Base is directed upwards
and backwards.
• It is situated posteriorly
opposite the T5 to T8 vertebra.
• It is formed mainly by the left
atrium
• Between it and the thoracic
vertebra lies the pericardium,
oesophagus, descending aorta,
vagus nerve and thoracic duct.
Dr Ndayisaba Corneille

26. The apex
• The apex of the heart is
rounded.
• It is formed by the left
ventricle and is at the level
of the fifth left intercostal
space, 9cm from the midline.
At this position the apex
beat is heard.
• The apex of the heart is
pointing inferiorly and to the
left, causing the long axis of
the heart to be at an acute
angle to the long axis of the
body
Dr Ndayisaba Corneille

27. The sternocostal surface
• The Sternocostal
surface is formed
mainly by the right
ventricle, part of the
right atrium and right
Auricle and a small
part of the left
ventricle.
• The Sternocostal
surface presents two
grooves an anterior
Interventricular sulcus
and the atrioventricular
sulcus. Dr Ndayisaba Corneille

28. The left surface
• The left surface is
formed by the left
ventricle. At the
upper end is part of
the left atrium and
the left auricle.
Dr Ndayisaba Corneille

29. The diaphragmatic surface
• The diaphragmatic surface
resting on the central
tendon of the diaphragm
is formed by the right and
left ventricles which is
demarcated by the
posterior interventricular
sulcus.
Dr Ndayisaba Corneille

30. The heart is
composed of
four chambers.
The right and
left atria
The right and
left ventricles.
CHAMBERS OF THE HEART
Dr Ndayisaba Corneille

31. DEMARCATION OF CHAMBERS OF THE
HEART ON THE SURFACE
• On the surface the chambers of
the heart are demarcated or
delineated by the following 3
grooves:
• A. Coronary sulcus
(atrioventricular groove).
• B. Anterior interventricular
sulcus.
• C. Posterior interventricular
sulcus
Dr Ndayisaba Corneille

32. The right atrium: EXTERNAL FEATURES
• A. The right atrium is elongated
vertically with the superior vena cava
(SVC) at its upper end and the inferior
vena cava(IVC) at its lower end.
• • B. The upper anterior part presents
the right auricular appendage, the
right auricle.
• C. A shallow vertical groove referred
to as sulcus terminalis extends along
the right border between the superior
and inferior vena cavae
Dr Ndayisaba Corneille

33. INTERIOR OF THE RIGHT ATRIUM
• On opening the atrium, a ridge –
the crista terminalis is seen to
correspond in position to the
sulcus terminalis on the exterior
indicates were the two primitive
chambers merge.
• The portion of the atrium behind
the crista is smooth, this part
develops from the sinus venosus.
• The portion in front is
trabeculated: it develops from the
primitive atrium.
Dr Ndayisaba Corneille

34. • The parallel ridge
running forward from
the crista terminales
towards the auricle are
called musculipectinati
(peten a comb).
• From the lower end of
the crista terminales a
prominent fold of
endocardium which
represents fetal valve of
the IVC, (though
imperfect) passes in
front of the orifice of the
IVC
Dr Ndayisaba Corneille

35. • This imperfect small valve
become continues with the
crescentic margin of a
depression the fossa ovalis
• which is situated in the
interatrial septum which
forms the medial wall of the
right atrium.
Dr Ndayisaba Corneille

36. • The right atrioventricular
orifice replaces the anterior
wall.
• The orifice of the coronary
sinus opens between the
orifice of the IVC and the
tricuspid orifice.
• It is also guarded by a fold
which arises from the valve
of IVC.
Dr Ndayisaba Corneille

37. • There is also the intervanous
tubercle of Lower which is a
very small projection at the
posterior wall of the atrium
just below the orifice of SVC.
• During IUL it directs SVC blood
to the right ventricle.
Dr Ndayisaba Corneille

38. LEFT ATRIUM
• The left atrium forms 2/3rd
of the posterior surface of
the heart, though its
auricle extends up to the
left border.
• It is demarcated from the
left ventricle below by the
coronary sulcus.
• The right and left
pulmonary veins open into
it, near the right and left
margins.
Dr Ndayisaba Corneille

39. The interior of the left atrium
• In the interior of the left
atrium the auricle is
trabeculated, the rest
part is smooth,
• the mouths of the four
pulmonary veins open
on the posterior wall.
• The left atrioventricular
orifice and the interatria
septum replaces the
anterior wall.
Dr Ndayisaba Corneille

40. • The septal wall shows the
fossa lunata which
corresponds to the fossa ovalis
of the right atrium.
• the rough part of the atrium is
derived from the primitive
atrium while the smooth part
is formed as a result of
absorption of the developing
pulmonary veins.
• Nothing is obtained from the
left horn of the sinus venosus.
Dr Ndayisaba Corneille

41. VENTRICLES
• The ventricles – right and
left lie in front of their
atria.
• They form the apex of the
heart, the entire inferior
margin and diaphragmatic
surface, most of the left
margin and sternocostal
surface, and a very small
part of the base.
Dr Ndayisaba Corneille

42. VENTRICLES
• On cross section it is seen that
the thickness of the two
ventricles is proportion to the
amount of work each has to
do.
• The left ventricle is the pump
of the systemic system while
the right ventricle is the pump
to the pulmonary system, so
the ratio of their thickness is
3:1. Myocardium of left ventricle is much thicker than the right.
Dr Ndayisaba Corneille

43. THE RIGHT VENTRICLE:
• This is the chamber of the heart
which receives blood from the
right atrium and pumps it out
through the pulmonary trunk to
the lungs where the blood is
oxygenated.
• It is triangular in shape but in
cross section it is crescentic in
shape due to the bulging of the
interventricular septum into its
cavity.
Dr Ndayisaba Corneille

44. • It is separated from
the right atrium by
the coronary sulcus.
Dr Ndayisaba Corneille

45. The interior of the right ventricle
• The interior of the right ventricle
presents muscular bundles called
trabeculae carneae which correspond
to the part derived from the primitive
ventricle.
• Some of muscle bundles are merely
elevated ridges,
• other are attached at both ends like
bridge, this is the septomarginal band
or moderator band through which
passes the right fasciculus of
atrioventricular bundle of HIS
Dr Ndayisaba Corneille

46. • others form finger like
projections called the papillary
muscles which here are
present anterior, posterior and
septal papillary muscles.
• From the apex of these
papillary muscles arises the
chordae tendinae which
attaches it to the ventricular
surface of the atrio ventricular
valves.
Dr Ndayisaba Corneille

47. • The smooth out flowing part of
the right ventricle is referred to as
the infundibulum.
• It is the conical upper 2.5cm of the
right ventricle that give rise to the
pulmonary trunk. It is derived
from the bulbous cordis.
• The two parts are separated by a
muscular ridge called the supra
ventricular crest, which lies
between the tricuspid valve and
pulmonary orifice.
Dr Ndayisaba Corneille

48. THE LEFT VENTRICLE
• The left ventricle is the heart chamber that pumps
oxygenated blood which enters it through the left
atrium to the systemic circulatory system through
the aorta.
• The left ventricle forms part of the sternocostal,
diaphragmatic and left border of the heart.
• It also forms the apex of the heart which lies at the
5th intercostal space where the apex beat is felt.
Dr Ndayisaba Corneille

49. • The cavity of the left
ventricle is longer then
that of the right ventricle.
It is also circular in cross
section.
• It has two parts – a rough
area that presents the
trabeculae carneae. It
develops from the
primitive ventricle.
Dr Ndayisaba Corneille

50. THE INTERVENTRICULAR SEPTUM
• The interventricular septum
is fleshy, except at its
uppermost part which is
membranous.
• The fleshy or muscular part is
an out growth from the apex
of the heart,
• the membranous part is an
out growth from the
interatrial septum and right
side of the root of the aorta.
Dr Ndayisaba Corneille

51. • Failure of the fleshy and
membranous parts to
fuse results in an
interventricular septal
defect with subsequent
leakage into the right
ventricle from the high
pressured left ventricle.
Dr Ndayisaba Corneille

52. The valves of the heart
• The valves of the heart is
destined to ensure that
there is one-way directional
flow of the circulating
blood.
• The valves of the heart
include:
– The right and left atrio
ventricular valves
– Pulmonary and aorta
semiluna valves.
Dr Ndayisaba Corneille

53. The right
atrioventricular
valves is tricuspid
and the left is
bicuspid. Both
valves have
fibrous rings to
which the cusps
are attached.
Dr Ndayisaba Corneille

54. Dr Ndayisaba Corneille

55. Dr Ndayisaba Corneille

56. Dr Ndayisaba Corneille

57. Dr Ndayisaba Corneille

58. Venous drainage….
Venous blood from
heart drains into
right atrium through
a.Coronary sinus
b.Anterior cardiac veins
c. Venae cordis minimae
(thebesian veins)
Dr Ndayisaba Corneille

59. • 2 to 3cm long
• Situated – left posterior coronary sulcus
• Opens – right atrium.
• Valve- Thebasian valve
Tributaries are…..
1.Great cardiac vein
begins apex, and ascends through
the anterior Interventricular groove,
traverses – coronary sulcus.
It receives left marginal vein.
2.Small cardiac vein
passes along right posterior coronary
sulcus.
A.Coronary sinus…..
Dr Ndayisaba Corneille

60. 3.Middle cardiac vein
Begins – apex, traverses – PIG,
ends – middle of coronary
sinus.
4.Posterior vein of left ventricle
Present on diaphragmatic
surface of left ventricle.
5.Obligue vein of left
atrium(vein of Marshall)
Descends obliquely – back of
left atrium
Dr Ndayisaba Corneille

61. Drains anterior part of
right ventricle….
Usually 2 or 3 in number-
parallel to each other.
Opens to right atrium.
B.Anterior cardiac veins…
Dr Ndayisaba Corneille

62. • Opens into all
chambers.
• Numerous in
right atrium &
ventricle.
.Venae cordis minimae/Thebesian
veins…
Dr Ndayisaba Corneille

63. Dr Ndayisaba Corneille

64. Applied anatomy
• An atrial septal defect
is a birth defect of the
heart in which there
is a hole in interatrial
septum of the heart.
• The hole can vary in
size and may close on
its own or may require
surgery
Dr Ndayisaba Corneille

65. Ventricular Septal Defect
• A ventricular septal
defect (VSD) is a
birth defect of the
heart in which there
is a hole in the
interventricular
septum of the heart
Dr Ndayisaba Corneille

66. END
Dr Ndayisaba Corneille
THANKS FOR LISTENING
By
DR NDAYISABA CORNEILLE
MBChB,DCM,BCSIT,CCNA
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