Lecture 23- Cardio Phys Intro Flashcards
What does hemodynamics mean?
Study of the movement of blood
What is the function of the cardiovascular system?
To circulate blood at rates commensurate with metabolic demand while maintaining adequate perfusion pressure and low filling pressures
What does blood convey?
Nutrients
Waste
Gases
Electrolytes
Two conditions blood circulation must meet
Adequate perfusion pressure to reach surrounding tissues
Low filling pressures
How many pumps in the heart?
Two, pulmonary and systemic
What will happen if a ventricle is not fully emptying after contraction?
Venous pressures will rise
What is Stroke Volume?
The volume of blood the ventricle ejects each systole
What is cardiac output?
the volume of blood that leaves a side of the heart in one minute
What is the formula for cardiac output?
CO = SV x HR
Are the cardiac outputs of the left and right sides of the heart equivalent?
Yes
What side is the Mitral valve found on?
The left
What side is the tricuspid valve found on?
The right
What are the great arteries?
The aorta and the pulmonary artery
What valve is at the entrance to the great arteries?
Semilunar valves
What chamber of the heart acts as a “volume pump” or bellows?
The right ventricle
What chamber of the heart functions as a “pressure pump”?
Left ventricle
Where are resistance vessels that determine the distribution of cardiac output found?
Arterioles
How is blood flow to tissue controlled?
Changes in local resistance
Is arterial pressure regulation independent of control of local blood flow or cardiac output?
Yes
When does the AV valve close?
When the pressure in the atria is lower than the pressure in the ventricle
What is the pressure equation?
Force/Area = Pressure
Does pulmonary circulation have high or low O2?
Low
What are direct and indirect ways to measure arterial pressure?
Direct- catheter in vessel
Indirect- Doppler cuff, oscillometric
What is normal venous pressure usually?
0
What is a sign of right heart disease
Visible jugular pulsation due to increased venous pressures
What does Ohm’s law measure?
Resistance
What is the equation for Ohm’s law?
ΔP = CO x R
Change in pressure = cardiac output x resistance
Why are radius and viscosity important concepts in hemodynamics?
They can be manipulated with pharmaceuticals
What does Poiseuille’s Law measure?
Resistance
What is Poiseuille’s Law?
ΔP/Q = 8μL/Πr4
Change in pressure/cardiac output = 8μL/pi*radius^4
What is vascular resistance?
The sum of forces that must be overcome for flow to occur
Which is larger? Systemic vascular resistance or pulmonary vascular resistance?
Systemic vascular resistance
What causes ventricular suction?
Relaxation of the ventricles during diastole
Where does the largest proportion of blood volume reside?
In the systemic veins
What is Laminar Flow?
Parabolic flow
Associated with smooth flow
Central cells are moving faster than peripheral cells
What determines Turbulent/Disturbed flow mathematically?
Reynold’s number
Increasing viscosity increases or decreases likelihood of turbulence
Increases????
