Download Circulatory system

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General
Circulatory system
Heart
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1-Tunica interna: aka tunica intima
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1
Heart
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2-Tunica media:
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3-Tunica externa: aka tunica adventitia
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3
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Heart = pump
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Heart
auricle; lower, outer part of atrium
auricle = 'ear'
looks like a dog's ear.
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Pressure pushes blood into the atria
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Heart
Ventricles contract, ejecting blood into the
elastic arteries.
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no exogenous stimulation
With adequate 02 and chemical energy
heart will beat
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Heart
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Wall structure
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Tunica interna: endocardium.
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Medium to large hearts
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Heart
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Tunica media: myocardium.
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Tunica externa: epicardium.
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Special structures:
Cardiac Valves
Heart
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R and L semilunar valves
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Heart
Chordae tendonae and papillary
muscles
Tension-cords
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Ventricles contract, cords prevent
valve inversion
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Heart
The tunica media of all four chambers
of the heart are continuous
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Membrane impulse begins at sinoatrial (SA) node
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Heart
Medium to large hearts, Purkinje
fibers
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Only weakly contractile;
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Heart
Impulse reaches the interatrial septum
and the auricle 0.1 sec later.
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Bottom of the interatrial septum;
impulse reaches the atrio-ventricular
node (AV node)
Takes another 0.1 sec to pass through
the AV node
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Heart
Atrial tunica media thinner than
that of the ventricles
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Heart
Purkinje fibers extends down the
interventricular septum and
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Membrane impulse reaches the upper
ventricular walls
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Heart
The outer wall of the RV is much
thinner than that of the LV.
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Less force is required to pump
blood into the pulmonary trunk
than into the aortic trunk.
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Thickness of the
interventricular septum =outer
wall of the LV.
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LV lumen much more apparent
in sections of the heart than
lumen of the RV.
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Heart
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Heart
The heart sounds; closure of the
two sets of valves.
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First sound ('lubb') does not
occur when the atria contract,
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Second sound ('dupp')
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Heart
The depolarization and
repolarization of the cardiac
muscle tissue
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Heart
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P wave
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QRScomplex
T wave
no wave due to atrial repolarization
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