This document provides an overview of the cardiovascular system and anatomy of the heart. It discusses the key components of the heart including the four chambers, valves, layers of the heart wall, conduction system, and blood flow pathways. The cardiac cycle and factors that influence cardiac output like heart rate and stroke volume are also summarized. The learning objectives are to understand the structure and functions of the heart and cardiovascular system.

1. CARDIOVASCULAR SYSTEM
(Anatomy & Physiology)
S.S.MOORTHY SEMENCHALAM
M.Sc. Comm Health (Occ Health) UKM
B.HSc. Nursing (Aust)
Dip Med Sc. (Moh)
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2. Learning Objectives:
At the end of the session, students will be
able to:
1. Label the structure of the heart
2. List the 3 layers of heart wall
3. List all the chambers and valves of the heart
4. State the function of the chambers and valves
5. Define the physiology of the heart
6. List 3 stages in cardiac cycle
7. Understand how the heart sound is produced
8. Define cardiac output
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3. Cardiovascular system:
Components
1) Heart
Pumps blood into blood vessels
Located in the mediastinum (within the
pericardial cavity between the two lungs).
2) Blood Vessels
Carry blood throughout the body
Arteries, arterioles, capillaries, venules & veins
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4. An Overview of the Cardiovascular System
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5. Anatomy of heart
• Lies in thoracic cavity, 2/3 is to the left of
midline (mediastinum)
• Size: about a size of closed fist
• Cone-shaped with apex & base
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6. Apex
most inferior part of the heart,directed
anteriorly and to the left
 situated at the level of 5th intercostal space,
9cm to the left of the midline
Base
deep into sternum and extends to the 2nd
intercostal space
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7. Base
Apex
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8. ANATOMY OF THE HEART
PERICARDIUM
Double layered closed sac that surrounds the heart and
anchors it within the mediastinum
Consists of:
 fibrous pericardium:
- enclosing the heart & vessels
 serous pericardium
- allow heart to move freely
- parietal layer & visceral layer
- between the 2 layers = pericardial cavity
(filled with pericardial fluid  to reduce friction)
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9. Membranes around heart
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10. The Superficial Anatomy of the Heart
The heart consists of four chambers
Two atria and two ventricles separated by
septum
Major blood vessels of the heart include
Inferior vena cava
Superior vena cava
Aorta
Pulmonary trunk
Blood vessels
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11. The Superficial Anatomy of the Heart
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20.3a

12. The Superficial Anatomy of the Heart
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13. The Heart Wall
Composed of 3 layers
Epicardium: Outermost, serous membrane forming
the smooth outer surface consists of blood vessels
that nourish the heart wall.
Myocardium: Middle, muscular layer,responsible
for the ability of the heart to contract (cardiac
muscle tissue)
Endocardium: Innermost, endothelium(simple
squamous epithelium overlying connective
tissue.Also forms the valves of the heart.
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14. Connective Tissues
Connective tissue fibers of the
heart
Provide physical support
Distribute the force of
contraction
Prevent overexpansion
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15. Heart wall
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16. Heart Chambers &Internal
Anatomy
4 Chambers :2 Atria and 2 ventricles
Rt & Lt atria receive blood from veins and act
as resevoirs before it enters into the ventricles
Rt & Lt ventricles are the major pumping
system that forces blood into the arteries and
flow through the circulatory system
Septum : wall that divides the heart to the Lt
& Rt side
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17. Con`t
The wall of the left
ventricle is thicker than
the right ventricle
because it generates a
greater pressure as it
pumps blood to the
tissues of the whole
body. Whereas right
ventricle pumps blood
to the lungs.
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18. The Sectional Anatomy of the Heart
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19. Heart chambers and valves
HEART VALVES
Atrioventriculars valves (AV) – located between the Rt
atrium and Rt ventricle and Lt atrium and Lt ventricles
The AV between Rt atrium and Rt ventricle – TRICUSPID
VALVE
The AV between Lt atrium and Lt ventricles – BICUSPID or
MITRAL VALVE
The AV valves are connected to the heart wall by thin ,strong
connective tissue – CHORDAE TENDINAE
The aorta and pulmonary trunks has – SEMILUNAR
VALVES (aortic semilunar valve and pulmonary semilunar
valve)
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20. Functions of valves
•AV (atrio-ventricular) valves prevent
backflow of blood from the ventricles to
the atria
•Semilunar (SL) valves prevent backflow
into the ventricles from the pulmonary
trunk and aorta
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21. Valves of the Heart
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22. Structures leading to & from heart:
Superior & inferior vena cava – carry blood from the
body to the Rt atrium
Pulmonary artery- arises from the Rt ventricle,spilt
into the Rt and Lt pulmonary arteries,carry blood to
the lungs ( pulmonary circulation)
Pulmonary vein –carries blood from the lung to the Lt
atrium
Aorta- carries blood from the Lt ventricle to the body
(systemic circulation)
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23. HSC 1004-3/23 Jan 08
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24. Pathway of blood through the
Heart
2 Coronary arteries supply blood to
the heart- Lt and Rt coronary
arteries
Cardiac veins drain blood from the
heart & send it to the body.
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25. Coronary Circulation
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26. 3
1 BODY
Superior & Inferior AORTA
Vena Cavae Aortic valve
Right Atria Left Ventricle
Tricuspid valve Bicuspid valve
Right Ventricle Left Atria
Pulmonary valve
Pulmonary Artery Pulmonary Vein
LUNG 2
Physiology of the heart:
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27. LUNG
Right atrium Left atrium
1 2
3
Right ventricle Left ventricle
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28. Blood flow through Heart
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29. Cardiac muscle cell types
Autorhythmic cells: Specialized muscle cells
-Self depolarizing
-Form the conduction system and carry impulse
Contractile cells:
- Cells that contract in response to impulse
- Branched fibers
- Connected to one another by gap junctions.
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30. Cardiac Muscle Cells
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31. Conduction System of the Heart
Contraction of the atria and ventricles
is coordinated by specialized cardiac
muscle in the wall of heart that forms
the conduction system of the heart
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32. The Conduction System
The conduction system includes:
Sinoatrial (SA) node (pace maker of the heart)
Inter nodal pathway
Atrioventricular (AV) node
AV Bundle (Left and right branches)
Purkinje fibers
☺Conduction system sets sinus rhythm
(Responsible for heart beat)
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33. Impulse Conduction through the heart
SA node (pacemaker)
impulse
Travels through atria by inter-nodal pathway
Spreads to AV node
Travels through AV bundle (Bundle of
His)
Distributed throughout ventricles by Purkinje fibers
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35. The cardiac cycle
The event takes place within a single beat
Begins with the onset of cardiac muscle
contraction and ends with the beginning
of the next contraction
During a cardiac cycle
Each heart chamber goes through systole
and diastole
Lasts for 0.8 sec (75beats/min)
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36. Stages of Cardiac cycle
Atrial systole
Ventricular systole
Ventricular diastole
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37. Heart sounds
Auscultation – listening to heart sound via stethoscope
Two main heart sounds
S1 – “lubb” caused by the closing of the AV
valves
S2 – “dupp” caused by the closing of the SL
valves (shorter & higher pitched)
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38. Cardiac Output
Cardiac output – the amount of blood pumped by
each ventricle/minute
Stroke volume - the volume of blood pumped per
ventricles
CO = HR SV
Cardiac output Heart rate X Stroke
(ml/min) (beats/min) volume
(ml/beat)
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39. Cardiac output
Example…
CO = HR X SV
= 75 X 70 ml/min
= 5250 ml/min
= 5.25 L/min
All factors that control HR and SV will influence CO
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40. Factors Affecting Cardiac Output
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20.20

41. Thank you
Questions please….
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