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wiggers diagram y axis plots
in the cardiac cycle, blood moves from an area of _______ pressure to an area of ________ pressure
the pressure within each chamber rises in ______ and falls in ________
what are the phases of the cardiac cycle
3 places where pressure is generated
outflow vessels (aorta and pulmonary trunk)
what chambers change in the first phase (atrial contraction and ventricular filling)
- atria contract
- ventricles relax
what is the first period of cardiac cycle?
what s the second period of cardiac cycle?
what is the third period of cardiac cycle?
4th period ?
electrical activity in Atrial Contraction and Ventricular Filling
in Atrial Contraction and Ventricular Filling phase, pressure in the _______ is greater than the _________
in Atrial Contraction and Ventricular Filling phase which valves are open and which are closed?
AV valves are open and the Semilunar valves are closed
end diastolic volume
130-140 mL , one of the measures taken to see if someone has good cardiac health
what are the chamber changes in isovolumetric contraction
atria is relaxed
what is the electrical activity in the Isovolumetric Contraction phase
depolarization of the ventricles
in Isovolumetric Contraction, ventricular pressure ___________, and the ventricular pressure is ________ than the outflow.
less than the outflow
what are the AV and SL valve doing in Isovolumetric Contraction phase?
what are the ventricles and atria doing during Ventricular Ejection phase?
ventricles are contract and the atria are relaxed
what occurs electrically during the Ventricular Ejection phase?
ventricular plateau and repolarization occur
during Ventricular Ejection phase, ventricular pressure is _____________ than atrial pressure. the ventricular pressure is ________ than the outflow.
greater (blood will outflow and also out to the atria)
during Ventricular Ejection phase the Semilunar valve is ______ and the AV valve is _____________
what happens to the semilunar valves after the ventricular ejection phase?
the Semilunar valves immediately close (preventing back flow into the ventricle)
during Isovolumetric Relaxation phase the ventricles and the artia ________
during the Isovolumetric Relaxation phase, is there repolarization or depolarization
repolarization finished, then no activity
in Isovolumetric Relaxation, ventricular pressure is _________ than atrial pressure; ventricular pressure is ______________ outflow
the valves in Isovolumetric Relaxation are:
what is the electrical activity in Atrial Relaxation and Ventricular Filling phase?
no electrical activity
the ventricle and atria chambers in Atrial Relaxation and Ventricular Filling phase are what?
during Atrial Relaxation and Ventricular Filling, ventricular pressure is ______________ atrial and outflow pressure
in Atrial Relaxation and Ventricular Filling phase, the AV valves are ________ and the SL are ___________
what is the study of volumes in which the way the heart works
volume of blood left in the ventricle at the end of diastole stage is
end diastolic volume (EDV)
approximately how much blood is left in the ventricles during the end diastolic volume
end systolic volume (ESV) is the volume of blood left where and how much mL?
in the ventricle at the end of systole, 50-60 mL
stroke volume (SV) is the amount of blood pumped out where? how many mL
out of the heart with each heart beat , 60-70 mL per beat
what is ejection fraction a fraction of?
end diastolic volume
how do you calculate stroke volume? (what comes out every heart beat)
end diastolic volume - end systolic volume
this comes out of one heart beat
how do we calculate how much is coming out every minute? (cardiac output)
Heart rate x stroke volume
cardiac reserve is an increase in what
increase in CO above resting level
what is stroke volume dependent on?
(small heart, small volume)
cardiac output (maintenance) depends on what
what influences heart rate?
positive and negative chronotrope
what nervous system is involved with positive chronotrope
sympathetic nervous system
hormones of the positive sympathetic nervous system
what system is involved with the negative chronotrope?
peripheral nervous system
how do we stretch our heart muscle ?
fill it up with something more, (blood)
what does the cardiac center respond to in order to maintain homeostasis?
baroreceptors and chemoreceptors
what are the three ways to alter SV by altering the EDV?
preload is the degree the heart what
is stretched before it contracts
contractility is a force at which the heart ___________
after load is a force the heart must pump.....
against before ejection of the blood can occur
what was frank starling law of the heart?
The more the heart fills with blood during diastole, the greater the stretch on the wall, the greater the force of contraction during systole
what might increase filling time during preload?
lowering heart rate
how will u increase pressure going back into heart?
exercise (external compression)
what happens when the heart rate exceeds 160 bp?
the stroke volume declines because the filling time is significantly decreased
what happens to CO during rapid heart rate?
what happens to the stroke volume when you increase the maximum of the heart?
increase stroke volume
what alters the contractility of heart?
more calcium available
during contractility, the positive inotropic agent does what to calcium ++ (due to the presence of what)
increases ; epinephrine and norepinephrine
THYROID ALSO IMPORTANT
negative inotropic agent does what to calcium
one way to control the rate of the heart is to do what with calcium?
make less available
what is the pressure that must overcome before a semilunar valve opens?
the greater the afterload, the longer the __________________________ and the shorter the duration of _____________________________
what happens to the after load if something restricts the blood flow through the atrial system?
potential to increase afteload
_____________ is not working well, the ventricles accept more volume (ESV increases), they can't pump out effectively, so the chambers __________ in size
options for heart failure are :
intra-aortic balloon pump (IABP)
ventricular assist device (VAD)
what week does fetal heart develop?
what increases stroke volume
what decreases stroke volume
decreased venous return
increased mitral valve regurgitation
the contraction of the heart begins with autorhythimc depolarization of the _______ node located in the superior portion of the posterior atrial wall
from the ___________ , the wave of depolarization disperses through the myocardium of the atrium
depolarization then arrives at the ______________ node located in the inferior interracial septum
the AV node fires causing the signal to travel into the ________________________ as it passes through the _________________________
V bundle branches; inter ventricular septum
making a u turn at the apex of the heart, the signals are then carried by the _______________ through the exterior walls of the ventricles
If the right ventricle begins to pump an increased amount of blood, this soon arrives at the left ventricle, stretches it more than before, and causes it to increase its stroke volume and match that of the right. This is an example of
As the exercise progresses, muscular activity __________ venous return. This increases the _________ on the right ventricle.
During the depolarization phase of cardiac muscle :
voltage-gated sodium channels open.
In cardiac muscle, after the plateau phase and at the beginning of replolarization,
voltage-gated potassium channels open.
TRUE OR FALSE:
The plateau phase of the action potential in cardiac muscle delays repolarization to the resting membrane potential; therefore the refractory period is prolonged.false incorrect
Action potentials in ______________ muscle last longer than those in skeletal muscle.
component of the electrocardiogram: P wave
component of the electrocardiogram: QRS segment
component of the electrocardiogram: T wave
component of the electrocardiogram: PQ segment
trial contraction or atrial systole
component of the electrocardiogram: ST segment
ventricular contraction or ventricular systole
When blood is flowing out of the left ventricle, the bicuspid valve is __________ and the aortic semilunar
valve is __________.
Action potentials pass slowly through the ____________ in the conduction system?
Action potentials are carried by the ____________ from the _____________ to the ventricular walls.
Purkinje fibers; bundle branches
TRUE OR FALSE:
The action potential travels along the interventricular septum to the apex of the heart, where it then spreads superiorly along the ventricular walls.
In modifying cardiac activity, the parasympathetic innervation comes from the________________ center in the brain and the sympathetic innervation comes from the________________ center in the brain.
The resting membrane potential (RMP) of the SA node nodal cells is supported by an active Na+/K+ pump with a greater concentration of _________ outside the cell, a greater concentration of _______ inside the cell, and a calcium (Ca2+) gradient with ________ calcium outside the cell.
Na+; K+; more
SA nodal cells are unique in that they exhibit________________, meaning they are capable of___________ and firing an action potential spontaneously without any external influence.
The series of events in the SA nodal cells that cause autorhythmic contracts of cardiac muscle cells include slow voltage-gated sodium channels opening (without outside stimulation), depolarization from opening of fast voltage-gated _______________ channels to reach threshold, and repolarization from calcium channels closing and____________ channels opening.
What is the correct order of spread of the action potential through the heart's conduction system?
SA node, AV node, AV bundle, Purkinje fibers/cell gap junctions
order of mechanical events associated with cardiac muscle contraction?
Calcium entry into the sarcoplasm, calcium binds to troponin, muscle contracts, closing of calcium channels, calcium released from troponin, muscle relaxes
Which are characteristics of the heart when it is at rest prior to atrial contraction (atrial systole)?
- av valves are open
- all four chambers are at rest
- passive filling of the ventricles is under way
Autonomic influence on heart rate is controlled by__________.
what shunts blood away from the nonfunctional lungs of fetus and back into the placenta ?
atrial septal defect is a hole in the heart where?
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