3. Location
• The heart is
located in the
thoracic cavity
• Posterior to the
sternum
• Superior to the
diaphragm
• Between the
lungs
• The tip of the
heart is called
the ‘apex’
Image source – See slide 28
4.
5. FOUR CHAMBERS OF THE
HEART
Right Atrium Left Atrium
Right Ventricle
Left Ventricle
6. Arteries and Veins
Superior Vena Cava
Pulmonary Veins
Inferior Vena Cava
Aorta
Left Pulmonary
Artery
Pulmonary Veins
7. Right Atrium
• Receives de-oxygenated blood from the
superior vena cava and pumps it into the
right ventricle.
Right Atrium
Right Ventricle
(Heart)
8. Right Ventricle
• Receives de-oxygenated blood
from the right atrium and pumps
it into the pulmonary artery.
Right Ventricle
Pulmonary
artery
9. Left Atrium
• Is larger than the right atrium, it receives
oxygenated blood from the pulmonary
veins, and pumps it into the left ventricle.
Left Atrium
Left Ventricle
10. Left Ventricle
• Is larger then the right ventricle, it receives
oxygenated blood from the left atrium, and
pumps it into the aorta.
Left Ventricle
Aorta
11. Aorta
• Is the largest artery in the human body, it
receives oxygenated blood from the left
ventricle of the heart and moves it to all
parts of the body.
Aorta
12. Pulmonary Veins
• Carry oxygenated blood from the lungs to
the left atrium of the heart.
• Fact: They are the only veins that carry
oxygenated blood.
Pulmonary Veins
Pulmonary Veins
13. Inferior Vena Cava
• Is the large vein that carries de-oxygenated
blood from the lower half of the body into
the heart.
Inferior Vena Cava
14. Superior Vena Cava
• Is a large but short vein that carries de-
oxygenated blood from the upper half of
the body to the hearts right atrium.
Superior Vena
Cava
15. Valves of the heartThe valves are located
within
the chambers of the heart.
The function of the
valves:
• Controls the direction
of
blood flow
• Allows one way flow
of blood
- through chambers
- from the heart to
the body
Image source – See slide 28
Valves of heart
16. The four valves are known as:
the tricuspid valve
the pulmonic or pulmonary
valve
the mitral valve
the aortic valve
17.
18. The tricuspid valve:
Is an atrioventricular
valve, situated between
the atria and the
ventricle
Controls the opening
between the right atrium
and the right ventricle
19. The mitral valve:
Is an atrioventricular
valve, situated between
the atria and the ventricle
Controls the blood
between the left atrium
and the left ventricle
20. The pulmonic or pulmonary
valve:
Is a semi lunar valve which
controls the blood leaving the
heart
Situated between the right
ventricle and the pulmonary
valve
Controls the flow of blood
from the right ventricle
Prevents blood flow back to
the right ventricle, as it
21. Pulmonary circulation and the heart
The inferior and superior vena cava carry oxygen
depleted blood to the relaxed right atrium of the
heart
The right atrium contracts and blood travels
through the tricuspid valve into the relaxed right
ventricle
The right ventricle contracts, the blood is
pumped through the pulmonary valve into the
pulmonary artery to the lungs
Gas exchange occurs in the lungs
Co2 is released and oxygen is absorbed
The oxygen rich blood then travels via the
pulmonary veins to the left atrium
22. Systemic circulation and the
heart
Oxygen rich blood travels from
the lungs via the pulmonary
veins to the left atrium
The left atrium contracts, and
blood flows through the mitral
valve into the relaxed left
ventricle
The strong left ventricle
contracts and pumps oxygen
rich blood through the aortic
valve into the aorta
24. Cardiac conduction is:
the rate the heart conducts electrical impulses
The electrical pulses determine the
order in which the chambers contract:
the heart rate
The path the impulses travel:
Sinoatrial node (SA node)
Atrioventricular node (AV node)
Bundle branches
Purkinge fibres
25. The Sinoatrial node (SA) :
Is also known as the pace maker of the heart
The Sinoatrial node is:
Located in the upper wall of the right atrium
Made up of nodal tissue - both muscle and
nervous tissue
Where the electrical impulse begins
When the SA node contracts:
Nerve impulses travel through the heart wall
Both atria contract
26. The Atrioventricular (AV) node:
Is located between the atria and ventricles of
the heart
Made up of nodal tissue
The electrical impulse is carried from the SA
node, and the AV node is stimulated.
The AV node delays the path of the impulse,
long enough for the atria to contract and
empty
27. Atrioventricular bundle branches:
are located between the atria and
the ventricles.
Fibres branch into two bundles -left
and right side of the heart
The electrical impulse travels from
the AV node to the bundle branches
after the atria have contracted and
emptied.
The AV bundle branches then carry
the impulses down the centre of the
heart to the left and right
28. The AV bundles start to divide
further into:
Purkinje fibres
Purkinje fibres:
Located at the end of the AV
bundle branches, at the base of
the heart
The Purkinje fibres are
responsible for the contraction
of the ventricles
