Lesson 1a: Fluid Properties and Colour Doppler Flashcards
The ____ the pressure, the greater the flow rate
greater
Volumetric Flow Rate = ____ / _____
Pressure (dyne) / Resistance (poise)
If flow resistance increases, volumetric flow rate _____-
decreases
Flow resistance depends on
1)
2)
3)
1) Fluid Viscosity
2) Tube length
3) Radius
As tube length increases, flow resistance ____
As radius increases, flow resistance ____
If viscosity increases, flow resistance ___
Increases
decreases
increases
This type of flow occurs at the entrance of a tube or vessel
Plug flow
Streamlines are straight, parallel to each other
Laminar flow
A form of laminar flow, when max velocity is in the centre and the average flow is half the max flow
Parabolic Laminar Flow
Flow that is no longer parallel but still considered to be laminar, occurs when there is bifurcation
Disturbed flow
Random, chaotic flow in all directions
Turbulent Flow
As diameter of the stenosis increases, flow speed increases to maintain flow. What rule is this?
Continuity Rule
As flow speed in the stenosis increases, pressure ____
decreases
The stacking of RBC’s is known as _____ Effect
Rouleaux
Conditions that cause Rouleaux formation include
1)
2)
3)
4)
5)
1) Multiple Myeloma
2) Infection/ Inflammation
3) Waldenstrom’s Macroglobulinemia
4) Diabetes Mellitus
5) Cancers
Poiseuille’s Equation calculates
Volumetric Flow rate
Bernouille’s Equation calculates
Pressure change
Doppler Effect is the change in ___ caused by the motion of sound source
Frequency
Propagation speed of sound through tissue is _____
1540 m/s
Doppler shift is the change in ____ caused by motion
Frequency
Doppler Shift is proportional to
1)
2)
1) Speed of blood flow
2) Operating Frequency
The angle between the direction of blood flow, and the sound propogation direction, is called the __________ or _________ angle
Insonification or Isonation
While Doppler Angle increases, Doppler Shift Frequency ________
Decreases
When the COSINE of the Doppler angle increases, Doppler Shift Frequency _______
Increases