Lesson 2C Part 3 Flashcards
What happens in low flow states
Red cells stick together which increases viscosity
Clotting mechanisms lead to
Entrapment of red blood cells and clot foramtion which raises pressure
Temp and viscosity have what kind of relationship
Inverse
Major regulator of vascular resistance is
Vessel radius
Increased fatty tissue required more
Blood vessels to service us and adds to the toal vessel length in the body
The longer the vessel length the _______ the resistance
Greater
Vessel resistance is ____ proportional to the viscosity
Directly
Vessel resistance is ______ to the radius to the fourth power
Inverse proportional
Vessel resistance is ______ to the length of the vessel
Directly
Peripheral resistance is controlled by what two things
Sympathetic nerve innervation
Autoregulation
the arterioles are the ________ of the vascular tree
Stopcocks
What is reactive hyperemia
Defined as the marked increase in blood flow which follows restoration of arterial inflow to a previously ischemic limb
Driving pressure for flow is determined by
Potential energy and kinetic energy
Energy loss is highest in region of
Stenosis due to consdierable friction from turbulent and vortex motion
Inside the stenosis there is a _____ in kinetic energy
Increase and an increase in blood velocity
According to bernouilis principle ther is corresponding
Fall in blood pressure after stenosis
Venous complaince is _____ to arteries
30x larger
Where is atheroma evident
Spectral doppler analysis
Plug flow has
All the same velocities
Parabolic flow (laminar) has
Highest flow in the center
Laminar flow profile is determined by
Fractional and inertial forces between the layers of blood and changes through out the pulse cycle
At low velocity, fluid flow is
Laminar
Turbulent flow aka
Abnormal flow
Turbulent flow occurs at ___ velocities
High
What happens in terms of energy with turbulent flow
Irreversible loss of energy
Disturbed flow is
Non random seperation of flow in vessel with obvious change in lumen size
Is there an increase in flow velocity with disturbed flow
No just spectral broadening occurs
Collateral flow arrises due to
Ischemia
Anastomosis is
Branches connecting form adjacent blood vessels
Where can collatera circulation occurs where
In both vein and arteries
Where is the triphasic waveform usually found
In arteries supplying a high resistance peripheral vascular bed
