List the four sonographic features that are usually evidence for a hemodynamically
significant stenosis - ✔️✔️proximal velocity signals will be dampened, max velocity at
stenosis with spectral broadening, post stenotic turbulence, downstream tardis parvis
Pressure is the lowest before, at, or after an obstruction vessel? - ✔️✔️at point of
maximum stenosis, pressure decrease, flow decrease pg. 170 Daigles
The appearance of enlarged channels that attempt to bypass an obstruction or
hemodynamically significant stenosis is called - ✔️✔️collateral vessels, pg. 37 Davies
the type of flow from all blood cells moving at about the same speed is - ✔️✔️plug flow
pg. 20 Davies
the simplified formula for flow, Poiseulli's law - ✔️✔️Q=P/R pg. 168 Daigles/ Davies
pg.22
Poiseuilles equation when the radius is known - ✔️✔️Q= change in P(pi)r^4/ 8nL, pg
168 Daigles
Q - ✔️✔️flow
triangle P - ✔️✔️change in pressure
N - ✔️✔️viscosity
L - ✔️✔️length
What law states that the volumetric flow rate must be constant, proximal,, within distal to
a stenosis - ✔️✔️Continuity rule,
the highest pressure in the cardiovascular system in a normal healthy supine patient is
in - ✔️✔️left ventricle pg. 163 daigle
What system do we have - ✔️✔️a closed loop system, maintain constant flow rate
laminar flow that is found at bifurcation in a region of stenosis - ✔️✔️disturbed flow pg.
165 Daigles
What is the most significant factor contributing to resistance to resistance to flow -
✔️✔️radius of the vessel, pg. 22 Davies
, When there is sudden widening of a vessel, what happens to the flow of blood and
where might this occur? - ✔️✔️flow separation, flow near the outer walls and slows and
reverses then to join the stream , the bulb of carotid
the study of blood flow is called - ✔️✔️hemodynamics
Power doppler - ✔️✔️show if there is any flow at all in vessel
the type of flow that occurs in vessels that feed dilated vascular beds is called -
✔️✔️low resistance flow bed is big ,pg. 28 Davies
the type of waveform that occurs in vessels that feed dilated vascular beds is -
✔️✔️biphasic waveform ,pg. 28 Davies
the type of waveform that appears in leg and arms arteries at rest is called -
✔️✔️triphasic waveform, pg. 29 Davies
Name 3 examples where the velocity measurements may not be accurate -
✔️✔️measuring too close the vessel wall, wrong angle, certain medications, cardiac
effects (arrhythmia)
arteries dilate when exercise, does the pressure change? - ✔️✔️no because they will
be dilated even thouogh flow will be faster
What is a hemodynamically significant stenosis - ✔️✔️diameter and area reduction,
50% or greater, reduction in flow volume and pressure pg. 39 Davies
spectral broadening - ✔️✔️the filling of the spectral window
Tardis parvis - ✔️✔️slow rising
what law states with increasing flow over a stenosis, distal pressures will dramatically
decrease after exercise - ✔️✔️poiseulles law
what law contributes to the ability of airplanes to fly - ✔️✔️bernouillis law
what is known as a change in frequency caused by the motion of a sound source, a
receiver or a reflector - ✔️✔️doppler effect pg. 2 Daigles