Ecological Succession. ( ECOSYSTEM, B. Pharmacy, 1st Year, Sem-II, Environmen...
6. cvs 1
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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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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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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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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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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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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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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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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BODY Jan 08
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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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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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