Physiology of Fluid Dynamics Flashcards
A multibranched elastic conduit that carries blood away from the heart and outward to the most distant tissues is called the _________ system.
Arterial
The stroke volume is ___________________.
The amount of blood ejected
Increase heart rate=______ blood volume
Increase
The heart pump generates _________ energy.
pressure/Potential energy
What three things change as the wave move through the arterial system?
Propagation speed
Shape
Strength
What is the route of blood flow?
Left Ventricle
Aorta
Large arteries
Arterioles
Capillaries
Venules
Large veins
Vena Cava
Right atrium
T/F: The pressure gradient is necessary to maintain flow.
True
Cardiac output governs the amount of _______ that enters the arterial system.
blood
__________ and _____________ determines the volume of blood that leaves the arterial system.
Arterial pressure
Total peripheral resistance
Where is pressure at its greatest?
the heart
What is the word for pressure difference?
Gradient
The movement of any fluid medium between two points requires two things:
- A route
- A difference in energy
The volume of flow depends on the ________ difference between two points.
net energy
resistance and flow rate are __________ related.
Inversely
The main form of energy present in flowing blood is called ________.
Pressure energy
The ability of flowing blood to do work as a result its velocity is called _________.
(the energy an object has because of its motion)
Kinetic energy
This energy is measured in millimeters of mercury…..
Gravitational energy
In supine position, at the level of the ankle, hydrostatic pressure is 0 mmHg, and mean arterial pressure is _____ mmHg.
95
In standing position, at the level of the ankle, hydrostatic pressure is 100 mmHg, and mean arterial pressure is ________ mmHg.
195
The reference point for zero pressure is in _____________.
The right atrium of the heart.
The greatest amount of energy is produced at _________, where the greatest velocities are observed.
Peak systole
The type of flow thought to exist in many vessels is called _______.
Laminar flow
What are the two forms of laminar flow?
Parabolic
Plug
What is another name for artery?
Conduit
_______ is the thickness of a fluid.
Viscocity
Viscosity and Velocity are __________ related.
Inversely
Elevated Hematocrit (More RBC per volume of plasma) is an examples of ________ viscosity in the circulatory system.
High
Examples of low viscocity:
Low Hematocrit
Anemia
Normal hematocrit values:
37%-47% females
42%-52% males
What affects resistance?
Viscosity
vessel length
Vessel diameter
What is the equation for resistance?
R=8nL
DIVIDED BY
Pi r to the 4th power
________ law defines the relationship between volume flow (Q), Pressure (P), and Resistance (R).
Poiseuille’s law
Q=P/R is what law?
Poiseuille’s law
Which law helps figure out how much fluid is moving through a vessel?
Poiseuille’s law
Poiseuille’s law combined with resistance equation becomes:
Q=(p1-p2)pi r squared/8nL
What is the equation for pi?
3.1416
Vessel radius and Resistance are __________ related.
Inversely
What are the equations for ohms law?
Q=P/R
I=E/R
What is it called when continuous distinct streamlines break up and form small circular currents?
Eddy currents and vortices
Flow volume and pressure are ________ related only up to a certain point.
Directly
T/F: When flow changes from stable to disturbed, an increase in pressure no longer increases flow volume.
True
Reynolds number is a __________ number.
Dimensionless
What is the reynolds number equation?
Re=Vp2r/n
The development of turbulence depends mainly on _________________________.
Size of vessel
Velocity of flow
Laminar flow becomes disturbed when the reynolds number exceed ______.
2000
What can cause flow disturbance at low values?
Body movement
Pulsatility of blood flow
Irregularities of the vessel wall
Plaque
________ may cause vessel walls to vibrate; causing bruit.
Turbulance
The total energy contained in moving fluid is ____________.
The sum of potential
Bernolulli equation shows the velocity and pressure are ______ related.
Inversely
In the region proximal to a stenosis, the pressure energy is ________ and the kinetic energy is _______.
Higher
Lower
The _______ region to a stenosis has the highest total energy sum.
Proximal
As blood flow into a stenosis, the pressure energy ______ and kinetic energy ______.
Decreases
Increases
T/F: The area of stenosis has less energy than proximal to stenosis.
True
Distal to a stenosis, the pressure energy _______ and kinetic energy _______.
Increase
Decrease
The difference in pressure between two points in a vessel is called ________.
Pressure gradient (flow separation)
What causes flow separations?
A change in geometry of the vessel wall
A change in direction of the vessel
Flow of a continuous (steady) nature throughout systole and diastole, feeding a dilated vascular bed is called _______ flow.
Low-resistance
Flow of a pulsatile nature is called ________ flow.
High resistance
What arteries are characterized by high-resistance flow?
ECA
Subclavian
Aorta
Fasting SMA
Iliac
Extremities
What arteries are characterized by low-resistance flow?
ICA
Vertebral
Renal
Celiac
Splenic
Hepatic
Is it normal to see a normally high-resistance biphasic or triphasic doppler signal become monophasic proximal to a stenosis?
Yes
What is vasoconstriction?
Narrowing of a blood vessel
In response to vasoconstriction, the pulsatility of flow in medium-size and small arteries of the limbs ________.
Increases
In response to vasodilation, the pulsatility of flow in medium-size and small arteries of the limbs ________.
Decreases
What is vasodilaion?
Widening of a blood vessel
What is a cardiac arrhythmia?
Irregular heart beat
T/F: When determining the significance of a stenosis, calculation of a velocity ratio may be helpful.
true
What is the velocity ratio?
Highest ICA PSV/Distal CCA PSV
A double systolic peak may sometimes be referred to as ________.
Pulsus Bisferiens
T/F: Double systolic peak may be a normal finding in a young patient secondary to vessel wall compliance.
True
Regurgitation/Insufficiency of the aortic valve may result in:
Double systolic peak
Pandiastolic flow reversal
Significant flow reversal
A systemic decrease in peak velocities with a normal systolic upstroke usually represents a low ejection fraction secondary to __________.
Cardiomyopathy
What is cardiomyopathy?
Diseases of the heart muscle
With high cardiac output, PSV measurements may __________ the degree of stenosis in these cases.
Overestimate
With low cardiac output, PSV measurements may __________ the degree of stenosis in these cases.
Underestimate
With stenosis of the aortic valve, PSV may _______ a stenosis.
Underestimate
What is used to provide temporary assistance with left ventricular contraction by decreasing afterload?
Intra-Aortic balloon pump
What is the purpose of the intra-aortic balloon pump?
Increase coronary artery blood flow
With intra-aortic balloon pumps, PSV measurements may _________ the degree of stenosis.
Underestimate
T/F: A ventricular device provides aid to a patient in heart failure.
True
Left Ventricular Assist Device (LVAD) is implanted with one end attached to the ____________ and the other end attached to the ______.
Left Ventricle
Aorta
Which flow pump is most commonly used with LVAD?
Continuous flow pump
Which flow pump results in arterial flow that is non pulsatile?
Continuous flow pump
What are the two types of flow pumps?
Continuous
Pulsatile
With ventricular assist devices, peak systolic measurements may __________ the degree of stenosis.
Underestimate
What is the device used for both left and right ventricular assist?
Biventricular assist device
The most common finding suggestive of a cardiac abnormality is ______________________________.
A pulsatile venous doppler signal in the lower extrmity
T/F: Increased systemic pulsatility is consistent with elevated pressure in the right side of the heart.
True
Can be related to: Chronic venous insufficiency, heart failure, tricuspid valve regurgitation, chronic obstructive pulmonary disease, primary pulmonary hypertension, and renal failure.
Exercise should induce ______.
Peripheral Vasodilation
Dilation of blood vessels outside of the brain (Ex: arms, legs,, etc)
The resistance of blood flow caused by the ever-decreasing size of the vessel , especially in microcirculation is called _________.
Peripheral resistance
T/F: Exercise is probably the best single vasodilator of high-resistance vessels within skeletal muscle.
True
Flow to a cool, vasoconstricted extremity with have _________ flow.
Pulsatile
Flow to a warm, vasodilated extremity with have _________ flow.
Continuous
A stenosis usually becomes hemodynamically significant when the cross-sectional area of the lumen is reduced ______, which corresponds to a diameter reduction of ____.
75%
50%
In hemodynamically significant stenosis, both pressure and volume _______.
Decrease
T/F: Post stenotic turbulence is typically seen at the exit from the stenosis.
True
