Right atrium -> tricuspid valve -> Right ventricle -> pulmonary valve to pulmonary circulation -> left atrium -> mitral valve (bicuspid) -> left ventricle -> aortic valve to aorta
Valve opens passively/actively to pressure changes in ventricle?
Passively
What are the two major stages of the cardiac cycle?
Diastole and systole
What happens with volume when in diastole?
Volume increases
What happens with volume when in systole?
Volume decreases
What happens to the rate ventricular filling in the beginning of diastole?
Rapid
What happens to the rate of ventricular filling at the end of diastole?
Slows down
What is systole?
Ventricular contraction – blood shoots out/eje from ventricles
What is diastole?
Ventricular relaxation – filling
What happens to pressure when blood fills up a chamber?
Pressure increases
What happens when there is increased pressure in the atria?
AV valve opens
What’s the cardiac output when the venous return is zero?
Zero. Heart can only pump out what it receives
What is the venous return when at mean systemic pressure?
Venous return is zero
What happens to venous return when the right atrial pressure increase?
Venous return decreases
When right atrial pressure increases, what happens with left ventricular end diastolic volume?
Increases
When right atrial pressure increases, what happens to stroke volume and cardiac output?
They both increase
As venous return increases, what happens to right atrial volume and pressure?
They both increase
What is a positive inotropic agent and what is its function?
Achieve a new steady state that is at a lower right atrial pressure- which would increase venous return and match cardiac output
What happens to the mean systemic pressure when blood volume increases?
Pressure increases too
What happens to venous return with increased blood volume?
Venous return increases – meaning increase cardiac output by increasing right atrial pressure that pushes blood forward
What happens to mean systemic pressure and venous return with decreased blood volume?
Both decrease
What happens to afterload and cardiac output with increased total peripheral resistance?
Increase afterload and decrease cardiac output
When’s to venous return with increased total peripheral resistance?
Reduced. Because blood flows slower from arterial to venous side
Does the right atrial pressure change with increased total peripheral resistance?
No
Does the right atrial pressure change with decreased total peripheral resistance?
No
Does mean systemic pressure change with changes in total peripheral resistance?
No
What happens to venous return and cardiac output with decreased total peripheral resistance?
Increase to both, Blood flows at a faster rate from arterial to venous side
What happens to afterload with decreased total peripheral resistance?
Decrease
At low end-diastolic volume, what is the overlap of actin and myosin?
Too much overlap, leading to low stroke volume because ventricles unable to contract well
What results at TOO high end-diastolic volume?
Left ventricle dysfunction because not enough overlap to generate force
What is preload?
The amount of stretch on the walls of the ventricle
What is the relationship between end diastolic volume and ventricular wall stretch?
End diastolic volume increases stretch on the walls of the ventricle
What is the stroke volume when heart rate is low?
Stroke volume is high because the ventricle has more time to fill allowing greater end diastolic volume
What happens to end diastolic volume when heart rate is high?
EDV goes down
What is the relationship between heart rate, stroke volume and cardiac output?
CO= SV x HR
What is the relationship between heart rate and cardiac output?
Parabolic
What is afterload?
The amount of pressure against which the heart pumps
What happens to afterload with increased thickness of the ventricular wall?
Afterload decrease – greater force of contraction of the ventricle
What happens to afterload with large chambers (chambers with large radius)?
Afterload increases- ventricle has to work harder to pump the blood out
Is increase afterload good or bad on the heart?
Bad- as in, the ventricle has to work harder to pump the blood out. Makes it difficult to shorten the sarcomeres, requires more ATP and therefore myocardial oxygen demand
Does a positive inotropic agent increase or decrease in contractility of the heart?
Increase
Which receptor do positive inotropic agents act on?
Adrenergic agonists act through beta 1 receptors
True/False: veins are more compliant than arteries
True
What happens to venous pressure when there is an increase in venous volume?
Not significant change in pressure, because veins are compliant
What happens to a rate rail pressure when there isi an increase in arterial volume?
Significant increase in pressure because of low compliance
What happens to the stroke volume in aortic stenosis?
Stroke volume goes down because aortic valve is narrowed
What happens to systolic pressure in aortic stenosis?
Systolic pressure goes down
True/False: aortic valve closes at higher pressure than when it opens
True
What happens to stroke volume when there is an increased afterload?
Stroke volume decreases
What happens to resistance when the radius of the vessel is reduced?
Resistance increase
What equation shows the relationship between pressure, flow and resistance?
P= QxR
What is the relationship between length of vessel and resistance?
Directly proportional
What happens to flow with increased radius?
Flow increase
Veins have thin or thick wall?
Thin
Do veins have high or low pressure?
Low pressure due to high compliance
Do arteries have thick or thin wall?
Thick wall
Which side has more volume, venous or arterial?
Venous side
What is vessel compliance?
The distensibility of the vessel
Sympathetic nervous systems reduce Or increase compliance in both arteries and veins?
Reduce compliance
True/False: aging veins are still more compliant than young arteries?
True
Slope of which type of graph shows compliance?
V/P
Pressure on x axis
Volume on y axis
What is the equation used to determine mean arterial pressure?
MAP= 1/3 systole + 2/3 diastole
In aortic stenosis what happens with stroke volume and pressure?
Volume ejected goes down and systolic pressure may go down too
What happens to systolic pressure in arteriosclerosis?
