FUNCTION OF THE HEART
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Pump
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Blood transport system around body
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___________ is the pump that circulates blood to
all parts of the body
Arteries, veins, and capillaries are the structures
that take blood from the heart
Carries oxygen and nutrients to cells,
carries away waste products
Lymph system
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Returns excess tissue fluid to general
circulation
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Avg. 72 bpm, 100,000 beats per day
Superior and inferior vena cava bring
deoxygenated blood to the ________ atrium
Cardiopulmonary circulation
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Pulmonary artery
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Bring _______ blood from the lungs to the left atrium
Aorta
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Takes blood from the right ________ to the lungs
Pulmonary veins
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Circulation form the heart to the ________.
Takes blood from the left ventricle to the rest of the body
Four heart valves which are:
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Heart is a double pump
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Which means what?
Now look at the board for the order
circulation
Also see figure 13-5 pg. 266
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“Lubb dupp” sound
Comes from the valves closing
Lubb sound is heard 1st and made by
tricuspid and bicuspid closing (S1 sound)
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Loudest at the apex
Dupp sound is heard 2nd and is shorter
and higher pitched (S2 sound)
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Caused by the semilunar and pulmonary valves
closing
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SA (sinoatrial) node
 Pacemaker
 Sends out electrical impulses, spreads impulse over
the atria and makes them contract
AV (atrioventricular) node
 Carries impulse to Bundle of His
 Located b/t the atria and ventricle
Bundle of His
 Conducting fivers in septum
 Divides into left and right branches in ventricles to
Purkunje fibers
Purkunje fibers
 Cause ventricles to contract
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SA node>stimulates both artia>blood
flows from atria to ventricles via tricuspid
and bicuspid valves
At same time ventricles are relaxed
allowing them to fill with blood =
seminular valves closed so blood cannot
enter pulmonary artery or aorta
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AV node>stimulates contraction of both
ventricles>blood pumped into the
pulmonary artery and aorta
Atria are relaxed and tricuspid and
bicuspid valves close
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Ventricles relax>semilunar valves
close>heart rests briefly (repolarization)
Cycle then begins again with the signal
from the SA node
Each cardiac cycle takes 0.8 seconds and
represents one heart beat