Hemodynamics Flashcards
hemodynamics is the study of
blood flow in the circulatory system and refers to both power and blood
blood composition
plasma 55%
erythrocytes 45%
leukocytes/platelets <1%
hematocrit
makes up 45% of blood volume and is made up of RBCs
density (in reference to hemodynamics)
the mass per unit volume or the resistance of an object to accelerate
viscosity
the resistance to flow (more viscous=slower velocity)
veins accounts for ____ of blood
65%
there is relatively ___ volume and velocity in the capillaries
low
the capillaries have an area of _____ that of the other vessels
600-1000x
ASK SHANE AS IT SAYS 600-100
what is required for any fluid to flow
a pressure difference
the pressure difference can be created by the ____ or ____
heart
gravity
an increase in pressure results in an _____ flow rate
increased
Ohm’s law (actual vs for blood)
current= voltage/resistance
for blood
volume flow rate (Q)= ΔP/R
pressure gradient formula
P Gradient = (P1-P2)/L
L= distance
the total adult blood flow rate is approximately ______ and is called the
5000mL/min
cardiac output
what happens to the volume flow rate if the pressure gradient increases
flow increases
what happens to the volume flow rate if the resistance to flow increase
flow decreases
Poiseuille’s Law for Resistance
R= (8 x length x viscosity) / (π x radius^4)
what has biggest influence on resistance
radius as it is to the power of 4
viscosity increase = resistance ____
increases
increase tube length = ____ flow resistance
increases
a decrease in the radius or diameter = ____ in flow resistance
increase
Poiseuille’s Law for volume flow rate
Q= (ΔP x π x diameter^4) / (128 x length x viscosity)
increase in pressure difference and/or diameter will ___ the volume flow rate
increase
a decrease in the length of the tube and/or the viscosity of the fluid will ____ the volume flow rate
increase