Blood Flow and Pressure Flashcards
What is blood flow?
The volume of blood flowing through a vessel, an organ, or the entire circulation in a given period e.g. L/min
What is blood flow normally equal to?
Cardiac output
What does blood flow equal?
Equation
Blood flow (Q) = Circulatory pressure/peripheral resistance
What is resistance?
2
Opposition to flow
A measure of the friction blood encounters as it passes through blood vessels
What is total peripheral resistance?
The combined resistance of all the blood vessels
What is blood pressure?
The force exerted by the blood against any unit area of vessel wall
Units = mmHg
Why is arterial pressure not a stable value?
2
Pressure rises in ventricular systole
Pressure falls in ventricular diastole
What is a good value for blood pressure in the arteries during ventricular systole?
120 mmHg
What is a good value for blood pressure in the arteries during ventricular diastole?
80 mmHg
How is blood pressure recorded?
Systolic pressure over diastolic pressure e.g. 120 over 80
What is MSAP?
Mean systemic arterial pressure
What is the equation for MSAP?
Diastolic + 1/3rd (systolic + diastolic)
Given in mmHg
What is pulse?
The rhythmic pressure oscillations in the blood vessels that accompany each heartbeat
What is pulse pressure?
The difference between systolic and diastolic pressures
What affects pulse pressure?
2
Stroke volume
Distensibility of the arteries
