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46 Cards in this Set
- Front
- Back
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What is the term used to describe the study of physical and physiological principles governing the movement of blood through the circulatory system.
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Hemodynamics
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What is Flow (Q)?
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Flow is the VOLUME flow rate of blood
volume per time (ml/min) |
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What is vascular Ohm's Flow equation?
As resistance increases, flow will ? |
Q = (P1-P2) / R
Decrease |
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Which one of these will have the lowest pressure?
Left Atrium Right Atrium Capillaries Venules |
Right Atrium will have the lowest pressure
(its the final "exit point" P2 in circulation) |
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Poiseulle's law describes the 3 variables that alter resistance. What are these 3 variables?
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Vessel Radius (r)
Vessel Length (L) Blood viscosity |
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What is Poiseulle's law equation?
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R = 8 (viscosity) L / π r^4
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Decreasing a vessel's radius by half will cause ? to resistance
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increase RESISTANCE by 16x
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REMEMBER
Q = P1-P2 / R OR Q = (P1-P2) π R^4 / 8 (viscos) L |
REMEMBER
Q = P1-P2 / R OR Q = (P1-P2) π R^4 / 8 (viscos) L |
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Q = (P1-P2) π R^4 / 8 (viscos) L
Q is equal to ? P1 is equal to ? P2 is equal to ? R is equal to ? |
Q = Cardiac Output (CO)
P1 = Mean Arterial Pressure (MAP) P2 = Right Atrial Pressure R = Total Peripheral Resistance (TPR) |
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REMEMBER
because pressure in the exit point P2 (right atrial pressure) is always close to zero, the value is ignored! therefore P1-P2 = MAP |
REMEMBER
because pressure in the exit point P2 (right atrial pressure) is always close to zero, the value is ignored! therefore P1-P2 = MAP |
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Remember
CO = MAP / TPR or MAP = CO x TPR |
Remember
CO = MAP / TPR or MAP = CO x TPR |
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What will happen to CO (Flow) if resistance increases?
How will an increase in CO affect arterial pressure if resistance is held constant? How will vasoconstriction affect MAP? |
CO will decrease
Arterial Pressure will increase MAP will increase |
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In the cardiovascular system, ? is the regulated variable. The cardiovascular regulatory systems are centered on this variable.
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Arterial Pressure
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Resistance in SERIES is calculated how?
Resistance in PARALLEL is calculated how? |
R(organ) = R(arteries) + R(arterioles) + R(capillaries) + R(venules) + R(vein)
1/R(organ) = 1/R(arteries) + R(etc). |
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When an addition of an extra PARALLEL resistance is added, how will this affect the Resistance total?
Removing a Parallel resistance will affect the Resistance total how? |
Decrease total resistance
Increase total resistance |
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True or False
A capillary bed has a very low overall resistance to flow even though the resistance of a single capillary is relatively high. |
True
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Velocity of blood movement equation:
Velocity of blood movement is dependent on ? and ? |
V = Q / A
Velocity = Flow / Total cross area velocity of blood movement is dependent on FLOW (p1-p2/R) and Total Cross Section Area |
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Is velocity higher in the aorta or the total capillary beds?
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Aorta (smaller cross sectional area)
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Bernoulli's principle describes the relationship between ? and ?
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Velocity and Pressure
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Increase in velocity will ? static/transmural pressure in the area but will ? dynamic pressure.
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DECREASE static/transmural pressure
INCREASE dynamic pressure (kinetic energy) |
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A decrease in cross-section area will ? velocity and ? static pressure.
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Increase velocity
decrease static pressure |
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Blood normally flows through blood vessels in an orderly streamlined manner called ?
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Laminar Flow
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Describe laminar flow...
Velocity fastest? velocity slowest? is there mixing of layers of fluid? |
Velocity is fastest in the CENTER
velocity is slowest adjacent to inner arterial wall *no mixing between layers of fluid! |
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Characteristics of Turbulent Flow
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blood forced to move at a high velocity
KINETIC ENERGY of the flow overcomes the tendency of fluid layers to stick together causing fluid layers to break apart wasteful process that dissipates pressure energy |
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What will predict whether laminar or turbulent flow will exist in a blood vessel?
high ratio means...? low ratio means...? |
Reynold's number
a ratio of KINETIC Energy and VISCOUS component of system turbulent flow (high kinetic causes fluid layer to pull apart) low ratio = laminar flow (cause fluid layers to stay together) |
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Reynolds number equation:
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Re = ρ D v / (viscosity)
Re = ( density x diameter x Velocity ) / viscosity |
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Turbulent blood flow past a narrowed artery is called a ?
Detection of these indicates that ? of a vessel's cross-sectional area has occurred |
Bruit
REDUCTION of vessel's cross sectional area has occurred (causing velocity to rise) |
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The greater the shear stress that the blood exerts on the blood vessel wall the ? the velocity
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GREATER the velocity
shear stress increase = velocity increase |
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What cells sense changes in shear stress?
HOW do they respond to changes in shear stress? |
Endothelial cells
Release Nitric Oxide Anti-Coagulant factors ===> causing VASODILATION |
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? is equal to the change in volume that occurs in an object for any given change in transmural(static) pressure across the wall of the object.
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Compliance
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What is the Compliance equation?
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Compliance = Volume / Pressure
C = V / P |
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A stiff object will have a ? compliance.
The object will require a ? in pressure to achieve a given change in volume. |
Low compliance
large change in pressure |
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Volume will be greatest when compliance is ? and Pressure Total is ?
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Compliance is HIGH
Pressure total is HIGH |
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True or False
Veins have a lower capacitance and compliance than arteries of the same size. |
FALSE
Veins have a HIGHER CAPACITANCE and COMPLIANCE than arteries of the same size |
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Contraction of smooth muscle within either arteries or veins will make vessels ? capacitance and ? compliant.
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Reduced Capacitance
Less Compliant |
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Micturition is under ? control due to the external sphincter being skeletal muscle.
Micturition reflex is controlled by the ? nervous system |
Voluntary control
Autonomic Nervous system |
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When the bladder is filling with urine, ? control predominates
This RELAXATION of the detrusor muscle is via ? receptors. Contraction of the internal sphincter muscle is via ? receptors. External sphincters are closed by ? action |
Sympathetic control
β2 receptors α1 receptors voluntary |
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When the bladder is full, the fullness is sensed by ? in the bladder wall.
? control predominates -- it causes CONTRACTION in detrusor muscle and RELAXATION in internal sphincter |
mechanoreceptors
Parasympathetic |
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Preganglionic neurons from the sympathetic system travel with the greater splanchnic nerve to the adrenal medulla where they synapse on ? and release ACh.
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Chromaffin cells
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The adrenal medulla mainly secretes ? and small amount of ?
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Epinephrine 80%
Norepinephrine 20% |
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How does referred pain work?
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Sympathetic AFFERENTS carry visceral pain
they enter dorsal horn along sensory afferents from the skin and converge on the same nerve cells in the spinal cord with pain from the body surface. |
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Thermoregulatory sweat glands are activated by ?
they have what types of receptors? are they sympathetic or parasympth? |
ACh
muscarinic cholinoreceptors sympathetic adrenergic neurons |
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Where are parasympathetic division preganglionic neuron cell bodies found?
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Brain stem (midbrains, pons, medulla)
Sacral Spinal Cord |
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What controls the salivary glands and the nasal mucous glands?
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Parasymapthetic Nervous System
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Organophosphates can cause ACh buildup by ?
affects Somatic nervous system and ANS |
Blocks Acetylcholinesterase
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What is used to block muscarinic receptors when a patient is exhibiting SLUDGE.
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Atropine
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