Hemodynamics Flashcards
When does hemodynamics start
when Aortic Valve Opens
What is the stressed volume
the amount of blood contained within arteries
Which blood vessel has the highest resistance to blood flow
Arterioles
What is the unstressed volume
the amount of blood contained within veins
What happens to pressure and flow when arteries constrict
pressure increases and flow decreases
What happens to pressure and flow when veins constrict
pressure increases and flow increases
What two factors determine blood flow
pressure difference and resistance
What is the equation to find the pressure difference in blood vessels
dP = Q x R
The greatest pressure decrease occurs in which vessels
Arterioles
why are so many chronic diseases are clinically silent until the diseases are in advanced stages
capillaries act as a parallel circuit, it takes a large percentage of capillaries to be obstructed to increase its vascular resistance and decrease its blood flow and oxygen nutrient delivery.
Velocity changes produce cardiac “______” and blood vessel “_______”
murmurs
Bruits
What is the name of the instrument used to measure RBC velocity
Transducer, using the doppler principle
What is the meaning of laminar flow
Streamlined (one direction)
What is the meaning of turbulent flow
Many different directions
What is Reynold’s number
A measure of turbulence
Does turbulent flow increase or decrease flow velocity
Increase and thus transmits more pressure
How might lack of sun exposure be linked to cardiovascular disease
Exposure to UV radiation produces nitrates in the skin which can help make NO that is neeed for vasodilation, which is linked to cardiovascular disease
What is shear and where in blood vessels is it at its highest
A consequence of different velocities, it is at its high at the walls of the blood vessel
what is blood vessel compliance
The volume of blood a vessel can hold at a given pressure
What is the equation for compliance
C = V/P
Compliance/Elastance is a small but significant component of Resistance/Conductance known as
Stiffness/Distensibility
Compliance (distensibility) decreases when which two molecules are in excess in the vessel walls
Collagen and/elastin
What is Fick principle a measure of
Indirect measurement of cardiac output
What is the Fick principle equation
CO= O2 consumption/ (artery O - vein O)
Calculation of what differentiates Low Cardiac Output Heart Failure from High Cardiac Output Heart Failure
SVR (or TPR)
Which type of cardiac output heart failure has a low ejection fraction
Low cardiac output heart failure
How is mean arterial pressure calculated
MAP = ⅓ SAP + ⅔ DAP
How is pulse pressure calculated
PP = SAP-DAP
How is pulmonary vascular resistance calculated
PVR = (MPAP-LAP)/CO
How is systemic vascular resistance calculated
SVR = (MAP-RAP)/CO
Increased SV to what change in PP
Increased PP
Decreased SV to what change in PP
Decreased PP
Increased HR to what change in PP
Decreased PP
Decreased DR to what change in PP
Increased PP
