1. ANATOMY OF THE HEART

2. POSITION OF THE HEART
The muscular pump
that is located between
lungs, slightly to the
left of the breastbone.

3. SIZE OF HEART
Slightly larger than a human fist.
Weight of between 200 to 425grams
Heart is beating approximately 100,000 times
everyday

4. Anatomy of the heart
Has 4 chambers
Upper chamber – called atria ( left and right)
Lower chamber – called ventricle (left and right)
All 4 chambers are separated by wall of muscle
known as the septum

5. Chamber of the heart

6. Wall of the heart
Pericardium – the outer layer – the thin serous
membrane comprising the outer surface of the
heart.
Myocardium – middle layer – muscular wall of the
heart. This thickest middle layer of the heart is
composed of cardiac muscle tissue
Endocardium – inner layer – smooth inner surface
of the heart chambers and the valves

8. RIGHT ATRIUM
Receives blood from the body via superior and
inferior vena cava.
Highly distensible chamber - accommodate the
VR and maintain a low pressure ( 0 – 3 mmHg)
The actual pressure depends upon the volume of
the blood within the right atrium.
Blood flows down into the right ventricle across
the tricuspid valve.

9. Right ventricle (RV)
Is smaller because it only has to transmit blood
a short distance to the lungs.
The free wall is not as thick as the left ventricle
Blood flow out to the lungs via semilunar
pulmonic valve through the pulmonary artery

10. Left atrium (LA)
Blood returns to the heart from the lungs via 4
pulmonary veins that enter the LA
LA is highly compliant like a RA - LA pressure
is higher than RA (6 -10 mmHg)
Blood flows out into the LV across the mitral
valve.

11. Left Ventricle (LV)
Left ventricle (LV) is the largest chamber and
has a very thick muscular wall (it can generate
high pressures during contraction, as they have
to force blood flow through the aortic valve into
the body)
Blood from the LV is ejected across the aortic
valve into the aorta then to the rest of the body
and other organs.

12. How does blood travel through the heart?
SVC
RA
RV
PULMONARY ARTERY
LUNGS ( GAS EXCHANGE)

13. How does blood travel through the heart?
Lungs
Pulmonary Veins
LA
LV
Aorta Organs Rest of the body

14. Blood flow through the heart

15. Valves of the heart
Tricuspid valve
Pulmonary valve
Mitral valve
Aortic valve

16. Tricuspid valve
Also called atrioventricular or AV valves
Situated between the RA and RV
Has 3 leaflets with fibrous strands (chordae
tendineae) on their leaflets that attach to
papillary muscles located on the respective
ventricular walls
Prevents the backflow of blood from the RV

17. Mitral valve
Also called bicuspid valve
Between the LA and LV
Consist of 2 leaflets
Prevents the backflow of blood into LA from
the LV

18. Pulmonary valve
Situated between right ventricle and the
pulmonary artery that leads to the lungs
Has 3 leaflets
It prevents the backflow of blood into the right
ventricle from the pulmonary circulation

19. Aortic valve
Placed between the LV and the aorta
It consist of 3 semicicular leaflets.
Prevent backflow of blood from the aorta once
it has left the heart

20. The papillary muscles contract during
ventricular contraction and generate tension
on the valve leaflets via the chordae tendineae
to prevent the AV valves from bulging back
into the atria and becoming incompetent

21. Blood supply to the heart
Heart muscle needs more oxygen than any organ
except the brain , therefore the heart must have
generous supply of blood
The flow of blood that supplies the heart tissue
itself is the coronary circulation
Blood is supplied to the heart by coronary artery
– left and right

22. Coronary artery

23. Right coronary artery
Right marginal branch
– supply blood to the lateral wall of the RV
Posterior interventricular artery
-- within the posterior interventricular sulcus .
– supply blood to the ventricles posteriorly
It also supply blood - 55% to SA node
- 90% to AV node
- a portion of Bundle of His

24. Left coronary artery
Begins behind the left cusp of the aortic
semilunar valve and devide into 2 branch
1 – anterior interventricular branch which
decends in the anterior interventricular sulcus (
LAD).
-- supply blood to the ventricles anteriorly
2 – a circumflex branch which continous in the
coronary sulcus (LCx )
-- supply blood to most of the posterior wall of
the heart

25. Left Anterior Descending
Supply blood to :
Anterior 2/3 of septum
Right bundle branch
Anterosuperior division of the left bundle
Anterior wall of the left ventricle

26. Left circumflex
SA node (45%)
Posteroinferior division of left bundle ( a
portion)
Lateral wall of the LV

28. Conduction system of the heart
Consist of modified
cardiac muscle cells
2 nodes that play
fundamental parts in
this conduction
system

29. Conduction system
Sino – atrial (SA) node
– located in the posterior wall of right atrium
– also known as the pacemaker
-- a stimulus arising from the SAnode cause atrial
to contract
( impulse from SA node travel to the AV node)

30. Conduction system
Atrioventricular (AV ) node
-- found in the inferior part of the interatrial
septum.
-- It acts as a relay station

31. Conduction system
Then impulse passes through bundle of His (
atrioventricular bundle) , it is located in the
interventricular septum and devides to form the right
and left bundle branches.
Impulse then generate through Purkinje fibres which
form the branching of right and left bundle branches at
the apex of the heart.
Its function is to stimulate the ventricles to contract

32. Conduction system of the heart

34. Thank you