Exam prep Chapter 1 Flashcards
Tardus Parvus indicates which of the following ?
a. severe outflow disease
b. severe inflow disease
c. downstream arteriolar dilatation
d. showering emboli
b. severe inflow disease
TP wave form appearance in which the systolic upstroke is delayed. this wf shape is indicative of severe proximal / inflow disease.
As the blood vessel decreases in size, which of the following is true?
a. increase in velocity and pressure
b. decrease in velocity and pressure
c. increase in velocity and decrease in pressure
d. decrease in velocity and increase in pressure
c. increase in velocity and decrease in pressure
the continuity equation (Q=VA) indicates that where an area decreases, velocity increases. According to Bernoulli, where velocity increases, pressure decreases.
Which of the following is true in the presence of a nonhemodynamically significant stenosis?
a. there is a corresponding pressure increase at the point of stenosis
b. there is a corresponding pressure decrease distal to the point of stenosis
c. there is a corresponding pressure increase proximal to the point of stenosis
d. there is a corresponding pressure decrease at the point of stenosis
d. there is a corresponding pressure decrease at the point of stenosis
Pressure decreases at a point of a stenosis. In a nonhemodynamically significant stenosis, the pressure returns to normal distal to a stenosis because the velocity returns back to the prestenotic velocity.
Monophasic flow in a resting lower extremity artery
a. indicative of normal flow
b. indicative of moderate to severe disease
c. normal if the patient is > 60 years old
d. normal with ABI’s of 0.9 or greater
b. indicative of moderate to severe disease
Phasicity of the arterial wf indicates the resistiveness of the distal bed. In a resting lower extremity, the distal arterioles are high resistance. Therefore, a high resistance multi-phasic wf is expected. Monophasic flow indicates dilatation of distal arterioles, indicative of moderate to severe disease.
In the venous circulation, which of the following is the only variable of hydrostatic pressure?
a. height
b. gravity
c. density
d. viscosity
a. height
in the venous system, height or distance from the heart is the only variable in the equation.
Which of the following occurs with deep inspiration ?
a. increase in blood flow from the lower extremities to the right heart
b. there is an increase in blood flow from the upper extremities and head to the right heart
c. there is a decrease in subdiaphragmatic pressures
d. there is an increase in pressure in the thorax
b. there is an increase in blood flow from the upper extremities and head to the right heart
with deep inspiration , there is increased flow from the upper extremities and head as a result of decreased pressure in the chest
According to Poiseuille’s law, an increase in the pressure difference causes :
a. a decrease in flow
b. an increase in viscosity
c. an increase in flow
d. an increase in resistance
c. an increase in flow
Poiseuille’s law relates flow changes in pressure, the radius of the vessel, length of the vessel, and viscosity of the blood. As the pressure difference (ie gradient) increases, flow increases.
If the radius of a blood vessel is halved, what is the corresponding change in flow ?
a. the flow is 1/4 what it was before the narrowing
b. the flow is 1/2 what it was before the narrowing
c. blood flow is decreased by a factor of 16
d. Blood flow is decreased by a factor of 20
c. blood flow is decreased by a factor of 16
In Poiseuille’s law the the radius component is to the 4th power (r^4). A change in radius by one half is equivalent to a 16 fold decrease in flow.
According to Bernouilli,
a. there is no relationship between pressure and velocity
b. velocity increases as pressure increases
c. Pressure and velocity are inversely related to each other
d. velocity and pressure are directly related to each other
c. pressure and velocity are inversely related to each other
Bernouilli’s principle states that pressure and velocity have an inverse relationship as part of the law of conservation of energy.
What type of flow is commonly seen at the entrance of large vessels?
a. laminar
b. parabolic
c. chaotic
d. plug
d. plug
plug flow which resembles a flat wave front before the flow assumes a more parabolic shape, is typically seen in the proximal AO and at the entrance of large vessels.
When tardus parvus flow is present, it indicates ?
a. mild disease proximally
b. normal flow
c. disease proximal to the point of sampling
d. severe disease distal to the point of sampling
c. disease proximal to the point of sampling
tardus parvus is a delayed systolic upstroke consistent with proximal arterial disease. The normal arterial waveform has a sharp upstroke.
Which of the following increases as a vessel area decreases ?
a.pressure
b. velocity
c. flow
d.cardiac output
b. velocity
according to the continuity equation (Q=VA), velocity increases where area decreases.
The stationary RBC’s along the vessel walls are called the ?
boundary layer
The boundary layer is a stationary layer of RBC’s adjcent to the vessel wall. RBC’s progressively increase in velocity until the fastest flow in the center of the vessel is reached.
Distal to a nonhemodynamically significant stenosis ,
a. the velocity decreases and pressure increases
b. velocity and pressure decrease
c. there is a pressure drop
d. the velocity increases and pressure decreases
a. the velocity decreases and pressure increases
distal to a nonhemodynamically significant stenosis, the velocity decreases (returns to normal)
q23
