Term
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Definition
| A branch of classical mechanics that involves th relationships between energy gradients and blood vessel properties upson the movement of blood through the cardiovascular system. |
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Term
1. What is the normal hematocrit? 2. What is the remaining portion called? |
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Definition
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Term
| What is the difference between plasma and serum? |
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Definition
| Serum is plasma after clotting factors have been created. Thus plasma has fewer clotting factors compared to serum. |
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Term
What is viscosity? What is sheer rate? What is sheer stress? |
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Definition
1. (η) The degree of slipperiness between two layers of fluid. The ratio between sheer stress and sheer rate. The lower viscosity a substance is, the more slippery the "sheets" are. 2. Δv/Δx 3. Force per unit area that is needed to maintain the extra velocity (Δv) |
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Term
Why does blood have a "anomalous viscosity"? |
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Definition
| Sheer stress to sheer rate is non-linear and blood needs some inital energy to get it moving. Most prevalent at a low flow rate. |
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Term
| What are some factors that affect blood viscosity? |
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Definition
Hematocrit - higher hematocrit leads to higher viscosity Vessel radius - blood viscosity decreases as vessel radius decreases Linear velocity of the blood - slower the velocity the higher the apparent viscosity Temperature - Higher the temperature the lower the viscosity |
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Term
| What is the effect on velocity of blood that is in contact with the vessel wall? |
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Definition
| It is subject to more resistance, against the vessel wall, and thus has a lower velocity. |
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Term
| Compare Laminar Flow versus Turbulent Flow. |
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Definition
| Laminar flow is one where each layer of fluid moves parallel to each other. Turbulent flow is one where layers are moving so quickly that they begin to mix with each other. A result is a loss in energy due to the turbulence. |
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Term
1. At what Reynold's number is flow laminar, or streamlined? 2. At what Reynold's number is flow turbulent? 3. What is the critical point? |
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Definition
1. <2000 2. >2000 3. Critical point is where laminar flow becomes turbulent flow |
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Term
| What is the physiological example of turbulent flow in blood vessels? |
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Definition
| Stenosis. Stenosis near the valves is called a murmur while in the vessels a bruit. |
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Term
| Blood moves in the direction of _____ pressure to _______ pressure. |
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Definition
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Term
| What is the equation for total hydraulic energy of a system? |
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Definition
| Total Energy = P+1/2mv2 + ρgh |
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Term
1. What is the value of Mean Arterial Blood Pressure lying down? 2. How does standing up affect Mean Arterial Blood Pressure (MABP) in the feet? |
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Definition
1. 100 mmHg 2. Standing up increases the ρgh value of the Total Energy Equation which increases the pressure in the feet. Moves from 100 mmHg to 195 mmHg. |
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Term
| What is Intraluminal Blood Pressure? |
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Definition
| Pressure that blood exerts outward on the sides of the vessel |
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Term
| What is extraluminal blood pressure (interstitial fluid pressure)? |
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Definition
| A force that exists on the outside of the vessel towards the center |
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Term
1. What is transluminal pressure? 2. What is its effect on blood vessels? |
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Definition
1. The vector difference between intraluminal and extraluminal pressure. 2. This has an effect on the movement of water into and out of the microcirculation. (Ex. Standing up increases the transluminal pressure in the legs resulting in filtration of fluid into the tissue space) |
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Term
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Definition
The degree to which a vessel can expand which is defined as the change in volume per change in transmural pressure. C = ΔV/ΔPTm |
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Term
| What are two general ways that compliance is lost? |
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Definition
| Aging and Atherosclerosis |
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Term
| What is Mean Circulatory Pressure? |
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Definition
| This pressure reflects the compliance of the entire vascular system versus the blood volume. Effectively, this is the pressure that blood would have on the vessels if the heart was brought to a standstill. |
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Term
| What is the equation for Circumferential Tension (Law of LaPlace)? |
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Definition
T = (PTm)(r) States that the higher the vessel radius, the higher the wall tension must be in order to stand the same transmural pressure so that it does not rupture |
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Term
| Place these vessels in order from highest to lowest Wall Tension: Veins, Small Arteries, Capillaries, Aorta, Vena Cavae, Venules, Arterioles |
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Definition
Aorta, Small Arteries, Vena Cava, Arterioles, Veins, Venules, Capillaries |
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Term
| Which of the two vascular circuits is the low pressure system? Why? |
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Definition
| The pulmonary system functions in a low pressure system. This is to help faciliate diffusion and to maintain a low resistance of exchange of materials. |
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Term
| What is resistance in terms of fluid dynamics? |
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Definition
| Resistance is the combination of factors that decrease the energy of a system. Energy that is lost is transformed into alternative energy that is no longer available for flow. |
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Term
What is the equation for flow? |
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Definition
Q = ΔP/R Q - Flow ΔP - Change in Pressure R - Resistance |
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Term
| If we assure a constant flow rate, what will happen to the pressure along the length of the tube due to constant resistance? |
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Definition
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Term
| What is the equation for Poiseuille's Law? What factor affects flow rate the most according to the equation and how does that express itself in vivo? |
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Definition
Q = (ΔP∏r4) / 8lη Radius has the most effect on flow rate. This shows the clinical effect that decreased vessel radius has on blood flow rate. |
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Term
| What happens to velocity as cross sectional area increases? |
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Definition
| Velocity will decrease. Think capillaries with their larger cross sectional area. |
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Term
| With regard to the Total Energy Equation, what is "blood pressure" measuring? |
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Definition
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Term
| Resistances in series are ______. |
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Definition
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Term
| What is the equation for conductance? |
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Definition
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Term
| Conductance in parallel systems are ________. |
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Definition
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Term
| Blood flow is _______ because of the contractile nature of the heart. |
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Definition
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Term
| What is a way that the vessels limit the pulsatile flow? |
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Definition
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Term
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Definition
| The difference between the systolic and diastolic pressures |
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Term
1. What is the MABP? 2. What is a way to estimate Mean Arterial Blood Pressure (MABP)? |
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Definition
1. This is the average blood pressure during one cardiac cycle. 2. Add 1/3 Pulse Pressure to Diastolic Pressure. This is Due to the fact that most of the blood stays in the diastolic system. |
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