Arterial (Quiz 1) Flashcards
Label a waveform
…..
What does the end diastolic flow demonstrate?
It shows the direction blood is moving - where it is going
What does the spectral window demonstrate?
If it is clean, it is laminar flow
If not, it’s turbulent flow
What happens to the upstroke if there is a blockage between the heart and sample position?
it becomes longer
What is fluid energy?
blood always moves from an area of high energy to an area of lower energy.
Name the types of pressure.
dynamic, hydrostatic, and static
Describe each type of pressure.
dynamic: changing pressure due to heart pumping
hydrostatic: created by weight of gravity on fluid column
static: exists throughout the body based on fluid balance of what’s in the vessel and soft tissue
What is Bernoulli’s Principle?
when a fluid flows without a change in velocity from one point to another, the total energy content remains constant, providing no frictional losses
if velocity remains constant from one point to another, so does the energy
What does Bernoulli’s Principle demonstrate?
velocity and pressure are inversely related.
Where does turbulent flow happen?
When narrowing, blocking or a vessel branches
What is viscosity?
the friction that exists between bordering layers of fluid
How is viscosity related to velocity?
inversely related
What is a hydraulic filter?
converts the pulsatile output of the heart to a steady flow through the capillaries
(triphasic waveform comes from hydraulic filter property)
How is energy lost?
through friction and inertia
What is friction?
energy lost in form of heat
How is energy lost through inertia?
when a vessel branches or bifurcates, energy will be lost at branch points
(more severe branching angle, the more turbulent flow)
What are the relationship properties with velocity and flow?
V = Q/A
velocity is directly related to flow
velocoty is inversely related to area
(flow is constant because of closed system)
As the total cross-sectional area increases throughout the body, what happens to blood velocity?
decreases
the farther distal, the lower the velocity will be because of the greater cross-sectional area and energery loss (over time)
What does Poiseuille’s Law demonstrate?
radius and pressure change is directly related to flow
viscosity is inversely related to flow
Describe the resistance equation
resistance is equal to the pressure drop divided by flow
resistance is inversely related to radius/diameter
blood vessel length is virtually constant as is blood viscosity
What is vascular impedance?
resistance offered by a peripheral vascular bed to pulsatile flow
Describe low resistance patterns.
dilated distal arteriolar bed, antegrade flow, typical of vessels that supply organs
Describe high resistance patterns.
slight vasoconstriction, antegrade and retrograde flow, typically found in vessels that perfuse muscles
Regulation of blood flow into the distal tissue beds is regulated primarily by what?
arterioles