item 11 Flashcards
Contraction produces _ changes that leads to blood flow
pressure
Events on the right side of the heart ar the same as the left side, but the pressure are lower on the _
right - it doesn’t require pumping to the whole system - just the lungs
The first stage of heart pressure is ventricular _, resting cycle
diastole
Atrial diastole is rather long, with only a brief moment for atrial systole hat occurs right before _ _
ventricular systole
Isovolumetric contraction is when…
the blood contracts against closed valves, but pressure increases
The _ diagram integrates volumetric and _ changes in the heart
pressure
Electrical signals occur _ contractions
before
_ pressure is low, and fairly steady
atrial - it doesn’t require a lot to encourage blood to enter, nor to pump out into the ventricles…due to gravity?
_ ventricular pressure predicts its volume
left
Atrial systole has the atrial _, pushing blood into the ventricle, which volume comes up.
contract
Stroke volume is the amount of blood pumped _ _
each beat
Heart rate are the frequency of heart _
contractions
_ _ is the amount of blood flow to the entire body (L/min)
cardiac output
At rest, there is 0.07 L of blood in the heart, whereas at its peak there is _ L
0.14 L (double)
At rest, the heart rate is 60 beats/min. The frequency of heart contractions increases to a max of _ beats/min
180 = 3 times
cardiac output is lowest at rest at 4.2 L/min, whereas at its max it is _ L/min,
25.2 L/min (6 times higher!)
What is the correct order of electrical/pressure/volume events in the heart?
isovolumetric contraction
isovolumetric relaxation
ventricular ejection
ventricular filling
- ventricular filling
- isovolumetric contraction
- ventricular ejection
- isovolumetric relaxation
How does an event in the heart determine blood flow within and out of the heart?
?
What is the relationship between pressures and volumes in the heart?
?
How do changing pressures lead to opening/closing of the valves?
?
How can heart rate be increased and decreased?
?
What are the 3 factors that affect stroke volume?
?
What are the structural properties of a blood vessel?
?
What are the diverse types of blood vessels?
?
What forces allow blood to flow?
?
How do blood vessels control blood flow distribution?
?
What is cardiac output and how is it determined?
?
The cardiac cycle includes the following aspects:
a. the various phases in the _ _ of the heart
pumping action
The cardiac cycle includes the following aspects:
a. the various phases in the pumping action of the heart
b. periods of _ opening and closure
valve
The cardiac cycle includes the following aspects:
a. the various phases in the pumping action of the heart
b. periods of valve opening and closure
c. changes in atrial, ventricular and _ pressure, which reflect contraction and relaxation of the heart muscle
aortic
The cardiac cycle includes the following aspects:
a. the various phases in the pumping action of the heart
b. periods of valve opening and closure
c. changes in atrial, ventricular and aortic pressure, which reflect contraction and relaxation of the heart muscle
d. changes in _ volume, which reflect the amount of blood entering and leaving the _ during each heartbeat
ventricle (both words)
The cardiac cycle includes the following aspects:
a. the various phases in the pumping action of the heart
b. periods of valve opening and closure
c. changes in atrial, ventricular and aortic pressure, which reflect contraction and relaxation of the heart muscle
d. changes in ventricle volume, which reflect the amount of blood entering and leaving the ventricle during each heartbeat
e. the two major heart _
sounds
_stole is the period of ventricular contraction, and _stole is the period of ventricular relaxation
systole;
diastole
Does the atria undergo periods of contraction and relaxation?
yes of course, but the ventricles are the main show, so we refer to it as ventricular systole or diastole
The cardiac cycle begins with the ventricles and atria in complete _
diastole; relaxation
Ventricular filling: During mid-to-late diastole, blood returning to the heart via the systemic and pulmonary veins enters the relaxed atria and passes through the _ valves and into the ventricles under its own pressure
AV (i.e., atrioventricular)
Ventricular filling: During mid-to-late diastole, blood returning to the heart via the systemic and pulmonary veins enters the relaxed atria and passes through the AV valves and into the ventricles under its own pressure.
The return of blood from the veins to the heart, referred to as _ _, occurs because the pressure of the veins is greater than that in the atria
venous return
this explains why blood pressure refers to the veins more than the heart itself
Ventricular filling: During mid-to-late diastole, blood returning to the heart via the systemic and pulmonary veins enters the relaxed atria and passes through the AV valves and into the ventricles under its own pressure.
The return of blood from the veins to the heart, referred to as venous return, occurs because the pressure of the veins is greater than that in the atria. During this time, the pulmonary and aortic (i.e., semilunar) valves are _ because ventricular pressure is lower than that in the aorta and pulmonary arteries
closed
- you want the AV valves open while the ventricles are filling with blood, but you don’t want any blood to seep out into the arteries, until necessary. further, it’s hard to build pressure (the ventricular pressure is lower than the veins at this point), unless the semilunar/pulmonary and aortic values are closed
Later in _, the atria contract, driving more blood into the ventricles. Shortly thereafter, the atria relax and _ begins, finishing ventricular filling
diastole;
systole
the filling of the ventricles is from higher pressure in the veins which force itself in the heart, and facilitated by gravity once blood gets through the AV valves. everything’s calm while the ventricles fill up, and only then does pumping/action/systole occur
At the beginning of systole, the _ contract, which raises the pressure within them.
ventricles
At the beginning of systole, the ventricles contract, which raises the pressure within them. When ventricular pressure exceeds _ pressure, the AV valves close
atrial
At the beginning of systole, the ventricles contract, which raises the pressure within them. When ventricular pressure exceeds atrial pressure, the AV valves close; the _ valves remain closed because ventricular pressure is not yet high enough to force them open (venous pressure was pushing them, not the atrial pressure, although originally atrial pressure was higher)
semilunar
At the beginning of systole, the ventricles contract, which raises the pressure within them. When ventricular pressure exceeds atrial pressure, the AV valves close; the semilunar valves remain closed because ventricular pressure is not yet high enough to force them open (venous pressure was pushing them, not the atrial pressure, although originally atrial pressure was higher).
Does blood flow into/out of the ventricles at this point? Why/not?
no, bc all valves are closing/closed to build sufficient pressure
(this phase is called ISO- (same) - volumetric contraction, after all
Phase 2, isovolumetric contraction ends when…
ventricular pressure is great enough to force open the semilunar valves so that blood can leave the ventricles
When ventricular pressure falls below aortic pressure during _ _, the semilunar valves close, ending this phase, and marking the begining of diastole
ventricular ejection, ending ejection/systole
At the onset of early _, the ventricular myocarium is relaxing.
diastole
Ventricular pressure is simultaneously too _ to allow the AV valves to open, and too _ to keep the semilunar valves open during isovolumetric relaxation
high;
low
you need low pressure for the AV valves to open (venous pressure higher than atrial/ventricular pressure, causing them to open), whereas you need high pressure for semilunar valves to open (force ventricular pressure into aorta/pulmonary arteries)
The AV valves require low _ pressure to stay open, which is why they’re open during mid-to-late diastole and early diastole
ventricular
The _ valves require high ventricular pressure to stay open, which is why they’re open during systole only
semilunar
High ventricular pressure coincides with high _ pressure, but low _ pressure, and closed AV valves and open aortic and pulmonary (semilunar) valves
aortic;
atrial
Heart sounds occur during the…
closing of the valves (like slamming a door)
