ANAT41 Lecture Outline
Cardiovascular System - Heart
Anatomy of the heart
 Location: between the lungs, directly behind the sternum (in the
mediastinum); tilted so the apex is oriented toward the left
What cavity does the heart lie in?
 Size: A healthy heart is approximately the size of your fist.
Pericardium (serous membrane)
Layers:
1.
2.
3.
4.
Fibrous pericardium
Parietal pericardium
Pericardial cavity
Visceral pericardium
What is the function of the pericardium?
Layers of the heart wall:
1. Epicardium (visceral pericardium)
2. Myocardium
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ANAT41 Lecture Outline
Cardiovascular System - Heart
3. Endocardium
Which layer is a biopsy taken from?
Microscopic anatomy review:




Branched
Centrally located nuclei
Striated
Intercalated discs
Chambers of the heart
A. Atria (singular, atrium)


Auricles
Interatrial septum
B. Ventricles
Features:
 Papillary muscles
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ANAT41 Lecture Outline
Cardiovascular System - Heart



Chordae tendineae
Trabeculae
Interventricular septum
Grooves of the heart
A. Coronary sulcus (AV groove):
B. Anterior longitudinal (interventricular) sulcus:
Valves:
What is the purpose of the valves? They prevent backflow.
AV valves (atrioventricular valves): (lie between the atria and ventricles)
 Bicuspid or mitral valve (lies on the left side)
 Tricuspid valve (lies on the right side)
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ANAT41 Lecture Outline
Cardiovascular System - Heart
What determines when the valves are open and closed?
Semilunar valves: (lie between the ventricles and the large vessels that leave
those chambers)
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ANAT41 Lecture Outline
Cardiovascular System - Heart
Flow of blood through heart chambers.
A. Right atrium
1. Receives blood from:
2. Sends blood to:
B. Right ventricle
1. Pumps blood into:
C. Left atrium
1. Receives blood from:
2. Sends blood to:
D. Left Ventricle
1. Pumps blood into:
Heart Sounds –the sounds are created by the closing of the heart valves
Which valves produce each sound below?
“Lub”
“Dup”
Summary of circulation through the heart:
Inferior Vena Cava, Superior Vena Cava or coronary sinus  Right Atrium 
through tricuspid valve  Right Ventricle  through pulmonary valve 
pulmonary artery  pulmonary capillaries  pulmonary veins  Left Atrium
 through bicuspid valve  Left Ventricle  through aortic valve  aorta 
systemic arteries  systemic capillaries  systemic veins
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ANAT41 Lecture Outline
Cardiovascular System - Heart
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ANAT41 Lecture Outline
Cardiovascular System - Heart
Intrinsic Conduction system of the heart:

Neural Automaticity of cardiac muscle
Functions of the conduction system
1. Initiate beat of the heart
2. Conduct messages around the heart
3. Coordinate beating of atria and ventricles
Components
1. Sinoatrial node (SA node): "pacemaker"
2. Atrioventricular node (AV node)
3. AV bundle (Bundle of His)
4. Right and Left Bundle Branches
5. Purkinje fibers
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ANAT41 Lecture Outline
Cardiovascular System - Heart
The electrical activity of the heart is recorded on an EKG (electrocardiogram).
EKG =
A. P wave
B. QRS complex
C. T wave
Extrinsic Control of the Heart:
Where is the cardiac control center located in the brain?
It is controlled by our autonomic nervous system. Do you remember the two
subdivisions of this system?


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ANAT41 Lecture Outline
Cardiovascular System - Heart
How does each control the activity of the heart?
Calculation of cardiac output - The amount of blood ejected from the left ventricle
during a minute
CO= SV x HR
B. Heart rate =
C. Stroke volume =
D. Cardiac output =
Factors that can effect cardiac output:
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