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Criado por ecmarchese
mais de 10 anos atrás
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Specialized muscle cells _____ produce and transmit electrical impulses to create contraction and relaxation of the heart.
What are the components of the conduction system?
Known as the pacemaker of the heart. Located at the border of the SVC and RA.
What does the AV node do?
What is the normal pacing of the AV node?
Receives impulses from the AV node and conducts the depolarization wave to the apex.
Stimulation of ______ fibers causes depolarization of the cells and contraction occurs.
The heart contract from?
Where does depolarization begin?
The p wave represents?
The QRS wave represents?
The T wave represents?
What 2 nervous systems affect the heart rate?
Fibers attached to the SA and AV nodes via the vagus nerves controlling heart rate
What does the sympathetic nervous system do?
What is derived from the vagal cardiac nerves located in the neck?
What does the parasympathetic nervous system do?
Timing from the beginning of one heart beat to the next.
This begins with the closure of the semilunar valves, on EKG it is the end of the T wave to the onset of QRS
What are the 3 events of ventricular diastole?
This occurs from the closure of the semilunar valves to the opening of the atrioventricular valves.
What 3 stages are in the passive filling stage?
Blood enters the ventricles passively yet rapidly due to swift ventricular relaxation.
Flow is reduced and pressures begin to equalize.
Pressures equalize before mid-late diastolic pressures begin to rise.
During atrial contraction, how much blood is forced into the ventricles?
Closure of the AV valves
Closure of the semilunar valves
Opening of the AV valves
Atrial systole
What are the RA pressures?
What are the RV pressures?
What are the PA pressures?
What are the LV pressures?
What are the LA pressures?
What are the aortic pressures?
What is an abnormal heart sound that is caused by turbulent flow in the heart or great vessels?
What are the components of the pulmonary system?
What are the components of the systemic circulation?
Amount of blood ejected from the LV into the aorta
What is the equation for cardiac output?
The volume of blood ejected with each beat
What is the equation for stroke volume?
The hearts ability to increase cardiac output is dependent on what 4 things?
Filling of the heart during diastole
The resistance that the heart must pump against
Contractility of the heart muscle ( force of contraction)
Heart rate or the rate of contraction
What does the frank starling rule state?