Chapter 2 Vascular

Front 1

Where is the greatest pressure

Back 1

The heart

Front 2

What determines how much blood leaves the heart? ***@

Back 2

Arterial pressure and peripheral resistance

Front 3

Venous return equals . . .

Back 3

Cardiac output

Front 4

What causes blood to move through the circulatory system? ***

Amount of bloodflow depends on. . .

Back 4

Movement of any fluid requires a pathway and pressure/energy differential

Amount depends on energy difference and resistance

Front 5

At what pressure does blood leave the heart? $$@

Back 5

85-95mmHg this is a mean average

Front 6

Where does pressure begin to fall after leaving the heart? $$$@

Back 6

Pressure falls very little though distributing arteries,

Falls greatly at small arteries and arterioles, which are resistance vessels, falls to 25-30mmHg

Front 7

Flow refers to

Back 7

Volume per time

Front 8

Velocity refers to

Back 8

How fast is the blood moving, distance/time

Front 9

Steady flow is

Back 9

Constant flow

Front 10

Pulsatile velocities are due to ***

Back 10

Cardiac contractions

Front 11

Phasic flow is due to $$$

Back 11

Respiration

Front 12

The total energy contained in moving fluid is the sum of? ***

Back 12

Potential (pressure) energy

Kinetic (motion) energy

Gravitational(hydrostatic pressure) energy

Front 13

3 forms of energy loss $$$

Back 13

Friction - converted to heat

Viscosity - the thicker the greater friction, anemia vs elevated hematocrit

Inertia and momentum - object in motion well stay in motion and objects at rest will stay in rest unless acted on by external forces or constraints such as pulsatile flow, velocity, or directional changes. Ex at stenosis

Front 14

What increases viscosity?

Back 14

Elevated hematocrit

Front 15

Types of laminar flow $$$

Back 15

Plug flow

Parabolic flow

Front 16

What is the boundary layer

Back 16

Flow along vessel wall going slower than center

Front 17

Parabolic flow $$$@

Back 17

Flow faster in the middle

Front 18

Eddy currents are common at

Back 18

Bifurcations

Front 19

Turbulent vs disturbed flow. Which is associated with disease? $$$@

Back 19

Turbulent flow

Front 20

Reynolds number$$$@

Back 20

A unitless number

Predicts when stable fluid will become disturbed/turbulent flow

Laminar flow <1500

Disturbed flow >2000

Front 21

Resistance is ________ proportional to viscosity and length

Back 21

Directly

Resistance increases with increasing viscosity and length

Front 22

Resistance is _________ proportional to vessel radius

Back 22

Indirectly

Resistance increases as vessel radius decrease

Front 23

Poiseuille's Law $$$@

Back 23

Flow(Q) = pressure(P) / resistance(R)

Describes the relationship between pressure, flow, and resistance to flow

Front 24

Poiseuille's Equation $$$

Back 24

Front 25

What happens during early systole?

Back 25

Cardiac contraction

Aortic valve opens

High velocity ejection of blood

Front 26

What happens during late systole/ early diastole?

What is dicrotic notch?***

Back 26

Rapid deceleration and aortic valve closes

Dicrotic notch represents aortic valve closure- results in temporary flow reversal

Front 27

What happens in late diastole?***

Back 27

Low velocity or no forward flow

Depends upon the resistance of vascular bed

Front 28

What is a major factor that dictates flow through the system? ***

Back 28

Peripheral vascular resistance of the vascular beds, arterioles/venules

Front 29

Describe high resistance flow***

Back 29

Lol or no flow during (late) diastole

Forward flow during systole and late systolic flow reversal

Front 30

Describe low resistance flow***

Back 30

Forward diastolic flow throughout the cardiac cycle

Front 31

Where is low resistance flow common?

Back 31

Vessels supplying organs with a high metabolic rate, brain, kidney, splanchnic vessels after eating

Front 32

Area/velocity relationship and law$$$@

Back 32

Law of conservation of mass

Q = A x V

Area and velocity are inversely proportional

Front 33

Waveform proximal to a stenosis$$$

Back 33

Flow may or may not be dampened depending upon the severity

Front 34

Waveform at stenosis

Back 34

Increased velocity

Disorganized flow

Spectral broadening

Front 35

Post stenosis waveform ***

Back 35

Turbulence flow, reversal, Eddy currents and vortices

The turbulence will decrease pressure

Front 36

If stenosis is severe enough, flow and pressure remain. . . .

Back 36

Decreased due to energy loses.

Front 37

Define hemodynamically significant stenosis. . . $$@

Back 37

A stenosis that causes a notable reduction in flow(Q) and pressure (P)

Around 50% diameter reduction

Front 38

50% diameter reduction = ___ area reduction$$$

Back 38

75%

Front 39

Bernoulli's Principle$$$

Back 39

Describes the relationship between velocity and pressure

Total energy=pressure+kinetic energy+gravitational energy

Front 40

How are velocity(kinetic energy) and pressure related?***

Back 40

Inversely proportional

The higher the velocity, the lower the pressure

Front 41

When does vasodilation occur? $$$

Back 41

Any time bloodflow is reduced to the point it cannot accommodate the demand.

Front 42

How will resistance change depending on severity and demand?

Back 42

From high to low

Front 43

If blood pressure drops, how do vessels autoregulate?***

Back 43

They vasocontrict allowing for a constant blood flow volume

Front 44

If blood pressure rises, how do vessels autoregulate?***

Back 44

Vasodilation allowing for a steady blood flow volume

Front 45

What controls vessel autoregulation?$$$

Back 45

The sympathetic nervous system

Front 46

When is diastolic flow lost?$$$

Back 46

When vasodilation and collateral flow cannot accommodate the metabolic demands

Front 47

Affect of exercise in waveform. . .***

Back 47

Metabolic demands increase due to exercise, waveform will transform from high to low resistance.

Exercise is a vasodilator

Front 48

T/F Dst effects of disease may only be detectable following stress (exercise)***

Back 48

True

Front 49

Systolic upstroke shows$$

Back 49

Where the blood came from

Front 50

Diastolic flow shows***

Back 50

Where the blood is going

Front 51

Two types of laminar flow? Smooth flow

Back 51

Plug and parabolic flow

Front 52

Good collateralization versus bad

Back 52

There is good collateralization the waveform may remain unchanged if it is bad it will be significantly different

Front 53

Temperature affect on flow***

Back 53

Cool limb - pulsatile, high resistance

Warm limb - continuous, low resistance