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37 terms

heart structure 3

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structure from which chordae tendinae originate
papillary muscle
prevents blood movement from right ventricle to right atrium
pericardial cavity
membranes around the heart
pericardial sac
prevents blood movement from left ventricle to left atrium
mitral valve
gives rise to left and right pulmonary arteries
pulmonary trunk
drains blood from myocardium into right atrium
coronary sinus
inner lining of heart chamber
endocardium
layer largely composed of cardiac muscle tissue
myocardium
space containing serous fluid to reduce friction during heartbeats
pericardial cavity
drains blood from myocardial capillaries
cardiac vein
supplies blood to heart muscle
coronary artery
distributes blood to body organs except lungs
Aorta
compare structure of right atrioventricular valve with that of pulmonary valve`
the right atrioventricular valve is made of 3 large cusps that contain tendinae. the pulmonary valve is made of 3 smaller pocket like cusps that lack chordae tendinae
Describe the action of right atrioventricular valve when you squeezed the water filled right ventricle
The cusps of the right atrioventricular valve move upward into horizontal position and close the opening between right atrium and right ventricle
about what percent of blood from atria passes into the ventricles before the atrial walls contract
70
the period which a heart chamber is contracting is called
systole
the period during which heart chamber is relaxing is caled
diastole
during ventricular contraction AV valves are
closed
during ventricular relaxation, the AV valves are
open
the pulmonary and aortic valves open when the pressure in what exceeds the pressure in the pulmonary trunk and aorta
Ventricles
heart sounds are due to what? in heart tissues created by changes in blood flow
vibrations
the first sound of a cardiac cycle occurs when what are closing
AV valves
the sound created when blood leaks back through an incompletely closed valve is called
murmur
the second sound of cardiac cycle occurs when what closes?
semilunar valves
the fibers of the cardiac condiction system are specialzed what?
cardiac muscle tissue
normally what node serves as the pacemake of the heart
SA Node
the what node is located in the inferior portion of ineratrial septum
AV node
the large fibers on the distal side of the AV node make up what?
AV bundle of his
the fibers that carry cardiac impulses from the interventricular septum into the myocardium are called
purkinje fibers
what is a recording of an electrical change occuring in myocardium during the cardiac cycle
electrocardiogram
between cardiac cycles, cardiac myscle fibers remian what? with no detectable electrical charges
polarized.
the P wave corresponds to depolarization of the muscle fibers of what
Atria
the QRS complex corresponds to depolarization of the muscle fibers of what?
ventricles
the T wave corresponds to repolarization of the muscle fibers of the
Ventricles
why is atrial repolarization not observed in the ECG
Atrial repolarization occurs at the same time as ventricular repolarization.
a rapid heartbeat is called
tachycardia
a slow heartbeat is called
bradycardia