Vascular Ultrasound Questions with Correct answers
What are the two types of energy that exist in the circulation? Example
of each Correct Answer-Potential energy = pressure in the vessels
Kinetic energy = velocity of blood flow
Describe the energy transfer between potential and kinetic energy using
Bernoulli's equation Correct Answer-When the lumen increases, kinetic
energy (blood flow) is converted back to potential energy (pressure)
vice versa
What kind of pressure is located in the lower extremities and is used to
equalize pressure to the level of the heart? Correct Answer-Hydrostatic
pressure
What is laminar flow? Correct Answer-flow is faster at the center of the
vessel than at the outside due to friction of the endothelial layer
Poiseuille's law states: Correct Answer-Q = [ π * (P1 - P2) * r4 ] / 8Lη:
states that in a cylindrical tube, the mean velocity of laminar flow is
directly proportional to the pressure differences from the start to the end
of the tube and the square of the radius, while being inversely
proportional to the length of the tube and the viscosity of the fluid
Poiseuille's Law:
Small changes in the _______ may result in large changes in ________
_______ Correct Answer-radius
,volume flow
What are the factors for varying degrees of deviation from laminar flow?
(2) Correct Answer-1. Blood flow velocity changes
2. Diameter changes (alter lines of flow)
Laminar flow can be altered at ________, ____________, ________ and
__________ __________ Correct Answer-curves, bifurcations, branches
and stenotic lesions
The development of turbulence depends mainly on what? (2) Correct
Answer-1. size of the vessel
2. velocity of blood flow
Mild turbulence is likely to occur when? (3) Correct Answer-1. body
movements
2. changes in vessel dimensions
3. roughness of endothelial surface
Severe turbulence is likely to occur when? (4) Correct Answer-1. high
flow
2. stenosis
3. decreased diameter
4. high pressure to low pressure areas
,The heart maintains a _______ volume of blood and pressure at the
arterial end of the circulation. Correct Answer-high
What factors have a role in the amplitude and shape of an arterial
pressure wave? (4) Correct Answer-1. stroke volume
2. timing of ventricular ejection
3. peripheral resistance
4. stiffness of arterial walls
An increase in the factors influencing amplitude and shape of arterial
pressure wave will do what? Correct Answer-increase the pulse
amplitude and in some cases the systolic pressure.
What does arterial stiffness mean? When do arteries stiffen? Correct
Answer-refers to the elastic modulus of the wall material.
arteries stiffen towards the periphery and as you age
Describe pressure changes which occur throughout the circulation (4)
Correct Answer-1. Pressure begins high in the arteries; little resistance
2. Decreases slightly between aorta and arteries
3. Pressure decreases across the arterioles and capillaries; but resistance
increases significantly
4. Pressure continues to drop in the veins; resistance decreases
dramatically as well
, Pulsatile changes in minute arteries, arterioles, and capillaries are
reduced by ________________ and enhanced by ______________
Correct Answer-vasoconstriction
vasodilation
Pulsatile changes in small and medium arteries are reduced by
_________________ and increased by ______________ Correct
Answer-vasodilation
vasoconstriction
How does temporary cessation of forward flow or flow reversal occur?
Correct Answer-A negative gradient is created after a wave has passed
through one vessel but is still traveling through a more distal one during
the diastolic period of the cardiac cycle.
Flow reversal is generally only seen in which arteries? Correct Answer-
high resistance (lower extremity) arteries
List the factors determining severity of a stenosis (7) Correct Answer-1.
length and diameter of the narrowed segment
2. roughness of the endothelial surface
3. degree of narrowing (abrupt or gradual)
4. ratio of cross-sectional area of narrowed segment to normal segment
5. rate of flow
6. arteriovenous pressure gradient
7. peripheral resistance beyond stenosis
What are the two types of energy that exist in the circulation? Example
of each Correct Answer-Potential energy = pressure in the vessels
Kinetic energy = velocity of blood flow
Describe the energy transfer between potential and kinetic energy using
Bernoulli's equation Correct Answer-When the lumen increases, kinetic
energy (blood flow) is converted back to potential energy (pressure)
vice versa
What kind of pressure is located in the lower extremities and is used to
equalize pressure to the level of the heart? Correct Answer-Hydrostatic
pressure
What is laminar flow? Correct Answer-flow is faster at the center of the
vessel than at the outside due to friction of the endothelial layer
Poiseuille's law states: Correct Answer-Q = [ π * (P1 - P2) * r4 ] / 8Lη:
states that in a cylindrical tube, the mean velocity of laminar flow is
directly proportional to the pressure differences from the start to the end
of the tube and the square of the radius, while being inversely
proportional to the length of the tube and the viscosity of the fluid
Poiseuille's Law:
Small changes in the _______ may result in large changes in ________
_______ Correct Answer-radius
,volume flow
What are the factors for varying degrees of deviation from laminar flow?
(2) Correct Answer-1. Blood flow velocity changes
2. Diameter changes (alter lines of flow)
Laminar flow can be altered at ________, ____________, ________ and
__________ __________ Correct Answer-curves, bifurcations, branches
and stenotic lesions
The development of turbulence depends mainly on what? (2) Correct
Answer-1. size of the vessel
2. velocity of blood flow
Mild turbulence is likely to occur when? (3) Correct Answer-1. body
movements
2. changes in vessel dimensions
3. roughness of endothelial surface
Severe turbulence is likely to occur when? (4) Correct Answer-1. high
flow
2. stenosis
3. decreased diameter
4. high pressure to low pressure areas
,The heart maintains a _______ volume of blood and pressure at the
arterial end of the circulation. Correct Answer-high
What factors have a role in the amplitude and shape of an arterial
pressure wave? (4) Correct Answer-1. stroke volume
2. timing of ventricular ejection
3. peripheral resistance
4. stiffness of arterial walls
An increase in the factors influencing amplitude and shape of arterial
pressure wave will do what? Correct Answer-increase the pulse
amplitude and in some cases the systolic pressure.
What does arterial stiffness mean? When do arteries stiffen? Correct
Answer-refers to the elastic modulus of the wall material.
arteries stiffen towards the periphery and as you age
Describe pressure changes which occur throughout the circulation (4)
Correct Answer-1. Pressure begins high in the arteries; little resistance
2. Decreases slightly between aorta and arteries
3. Pressure decreases across the arterioles and capillaries; but resistance
increases significantly
4. Pressure continues to drop in the veins; resistance decreases
dramatically as well
, Pulsatile changes in minute arteries, arterioles, and capillaries are
reduced by ________________ and enhanced by ______________
Correct Answer-vasoconstriction
vasodilation
Pulsatile changes in small and medium arteries are reduced by
_________________ and increased by ______________ Correct
Answer-vasodilation
vasoconstriction
How does temporary cessation of forward flow or flow reversal occur?
Correct Answer-A negative gradient is created after a wave has passed
through one vessel but is still traveling through a more distal one during
the diastolic period of the cardiac cycle.
Flow reversal is generally only seen in which arteries? Correct Answer-
high resistance (lower extremity) arteries
List the factors determining severity of a stenosis (7) Correct Answer-1.
length and diameter of the narrowed segment
2. roughness of the endothelial surface
3. degree of narrowing (abrupt or gradual)
4. ratio of cross-sectional area of narrowed segment to normal segment
5. rate of flow
6. arteriovenous pressure gradient
7. peripheral resistance beyond stenosis
