Term
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Definition
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Term
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Definition
| Important role in movement of blood throughout vascular system |
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Term
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Definition
Moves the blood generating pressure
(potential energy) |
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Term
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Definition
| (the amount of blood ejected) creates pressure (or energy) waves which travel rapidly throughout system |
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Term
Potential energy
(pressure energy) |
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Definition
the main form of energy present in flowing blood
(heart pump) |
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Term
-pumping of heart
-Hydrostatic pressure |
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Definition
| Two components of potential energy: |
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Term
- Cardiac function
- Elasticity of vessel walls
- Tone of vascular smooth muscle
- Patterns
- Dimensions
- Interconnections of branching vessels
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Definition
| Factors influencing blood flow: |
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Term
- A difference in the energy level between two points
- a route which the blood flows
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Definition
For blood flow to occur between any two points there MUST be:
(boards) |
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Term
pressure difference
(gradient) |
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Definition
| what is necessary to maintain blood flow? |
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Term
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Definition
| Greatest pressure is where and gradually decreases as blood flows distally? |
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Term
- Friction(heat)
- Any resistance within pathway
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Definition
| Two types of energy losses from movement of fluid: |
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Term
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Definition
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Term
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Definition
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Term
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Definition
| (motion)Is the ability of flowing blood to do work as a result of its velocity |
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Term
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Definition
Heart considered 0 pressure reference point
(hydrostatic pressure)
mmHg |
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Term
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Definition
| Mean venoud pressure at supine pt ankle level |
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Term
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Definition
| Mean arterial pressure of supine pt ankle level |
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Term
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Definition
| acceleration phase of the pulse; pressure is evely distributed in all directions |
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Term
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Definition
| deceleration phase of the pulse; peripheral vessels exceeds volume pressure declines |
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Term
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Definition
| Higher flow rate in arterial or veins? |
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Term
- laminar
- movement
- length
- viscosity
- diameter
- inertial losses
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Definition
| characteristics of blood flow: |
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Term
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Definition
Blood moves in concentric layers, or laminate
Each layer flows at a different velocity |
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Term
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Definition
| In laminar flow velocity is slowest where? |
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Term
| higher pressure required to maintain flow |
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Definition
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Term
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Definition
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Term
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Definition
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Term
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Definition
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Term
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Definition
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Term
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Definition
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Term
| energy is lost in the form of heat |
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Definition
| As red blood cells rub together creating friction, what happens? |
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Term
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Definition
| Smaller or larger vessles creat greater friction and resistance |
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Term
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Definition
| What has the greatest effect on resistance? |
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Term
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Definition
| Slightest change in radius makes great difference, Why? |
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Term
- changes in direction and/or velocity
- increase with deviations from laminar flow
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Definition
| Inertial losses are caused by what? |
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Term
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Definition
| blood moves in concentric layers |
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Term
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Definition
Relationship between pressure, volume flow, and resistance
V=Q/A |
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Term
| How much fluid is moving through a vessel? |
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Definition
| Poiseuilles's Law asks what question? |
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Term
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Definition
| Radius is directly proportional to what? |
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Term
resistance increases
volume flow remains constant
to maintain volume flow, velocity must increase |
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Definition
| If radius decreases what happens? |
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Term
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Definition
| Radius is inversely proportional to what? |
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Term
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Definition
| pressure/flow relationships |
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Term
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Definition
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Term
- body movement
- pulsatility of blood flow
- irregularities of vessel wall and plaque
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Definition
| Lower values of reynolds number can be caused by what? |
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Term
total energy = potential (pressure) +
kinetic(velocity)+gravitational energy |
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Definition
Bernoulli
pressure/velocity
(equation) |
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Term
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Definition
| How is velocity and pressure related? |
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Term
- changes in geometry of vessel
- direction
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Definition
| flow seperations include: |
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Term
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Definition
| always moving forward; no decrease in pressure downstream, no flow away from the driving pressure |
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Term
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Definition
| systole,diastole, and late diastole |
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Term
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Definition
| forward flow throughout periphery |
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Term
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Definition
| temporary flow reversal b/c negative pressure gradient and peripheral resistance |
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Term
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Definition
supply high-resistance pheripheral vascular beds
decreases with vasodilation and increases with vasoconstriciton |
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Term
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Definition
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Term
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Definition
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Term
Low-resistance flow
(steady) |
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Definition
Feeding a dilated vascular bed
ICA, Vertebral, Renal, and post prandial SMA |
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Term
High-resistance flow
(pulsatile) |
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Definition
High resistive vascular beds
ECA, aorta, extremity arteries, and fasting SMA |
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Term
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Definition
| Reversal of flow disappears becoming monophasic when? |
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Term
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Definition
There is a major reduction in volume flow and pressure
cross-sectional area of lumen is reduced 75%
diameter reduction of 50%
During when? |
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Term
| dampened velocities with or w/o disturbance |
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Definition
| Proximal to stenosis what happens? |
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Term
increase in doppler shift frequencies and velocities
(spectral broadening) |
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Definition
| At Entrance, passes, and/or exits of stenosis what happens? |
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Term
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Definition
- Highly complaint
- Intraluminal (inside)
- interstitial (outside)
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Term
| circular cross-sectional shape |
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Definition
| Increased intraluminal pressure = increased transmural pressure =shape? |
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Term
| elliptical and the "dumbbell" |
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Definition
| Decreasing intraluminal pressure shape? |
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Term
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Definition
| Veins can carry more blood without an increase in what? |
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Term
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Definition
| the pressure due to the weight of a fluid in a closed system. The height of the column of blood is always referenced back to the level of the heart |
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Term
| there is no column of blood pressing on the vessels of the body, so there is virtually no hydrostsic pressure in the legs, as they are at the same levle ar the right atrium |
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Definition
| Why is hydrostatic pressure 0mmHg in a supine pt? |
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Term
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Definition
| In a supine 6 ft person venous pressure at the ankly = what? |
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Term
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Definition
| In a standin 6 ft person venous pressure at the ankle = what? |
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Term
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Definition
| It is estimated that how much blood shifts to the legs when a person who is lying down stand ups? |
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Term
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Definition
| About what persent of circulating blood in our body is moving through the venous system? |
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Term
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Definition
| The venous system is what, which refers to the ebb and flow that occurs in normal veins in response to respiration? |
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Term
- diaphragm lowers
- flow increases in thorax and head/arms
- pressure decreases in thorax
- pressure increases in abdomen
- Flow decreases and pressure increases in legs
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Definition
| During Inspiration what happens? |
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Term
- flow increases in abdomen and legs
- pressure decreases in abdomen and legs
- Pressure increases in thorax
- flow decreases in thorax
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Definition
| During expiration what happens? |
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Term
| Venous valves and leg muscles |
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Definition
| what two factors work together to overcome gravity in moving blood from lower extrimity to upper? |
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Term
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Definition
| deep veins are surrounded by what? |
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Term
| Alternately contract and relax, causing "milking" |
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Definition
| muscles do what to help blood move up the leg? |
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Term
| direct its flow back to the heart |
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Definition
| As the muscle pump moves the blood, the venous valves do what? |
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Term
| In perforating veins (connecters) |
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Definition
What directs the flow from the superficial to deep veins?
(Boards) |
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Term
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Definition
| Veins prevent what by trapping blood in their cusps as they close? |
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