Hemodynamics Flashcards
_____ is the study of the forces and motion of blood flow
or of blood circulation
hemodynamics
Blood flows due to _____ in the heart and _____ in the veins, returns to heart via _____
high pressure, low pressure, leg muscle contract
how does blood flow? from what to what?
Heart, Arteries, Arterioles, Capillaries, Venules, Veins back to lungs
what does this show?
how blood flows
What are the 4 chambers of the heart?
____ create high pressure
____ have low pressure so blood returns
Right atrium. left atrium, Right ventricle, Left ventricle
Ventricles, Atria
what returns blood to the Rt Atrium?
what does the superior vena cava drain?
inferior vena cava?
venous system
arms and head
abdomen and legs
how does the arterial system flow?
Pumped via left ventricle (LV)
Creates high pressure
Blood travel via aorta to systemic arterial system
Returns to heart via systemic veins (IVC and SVC), into right atrium
how does the pulmonary arterial system work?
Pumped via right ventricle (RV)
Creates high pressure
Blood travel via pulmonary artery to lungs
Returns to heart via pulmonary veins, into left atrium
we have ~ ____ liters of blood in our body. it is circulated at appro ____ L/min. which means our entire blood volume is circulated every ___.
5, 5, minute
what takes the shape of their container?
what are 2 examples?
fluid
gas and liquid
what causes resistance to flow?
examples?
viscosity
“thicker”
Syrup is more viscous than water
Blood is “thicker” or viscous than water
what does anemia cause?
lower viscosity, less RBC’s
what does polycythemia cause?
higher viscosity, more RBC’s
____ is the pressure blood exerts on vessel walls and
_____ is the energy of motion of blood
potential energy, kinetic energy
____ is the difference in pressures which causes fluid to flow (pump, gravity…)
pressure gradient
gravitational energy is described as ____________.
hydrostatic pressure
blood always flows from ____ to ____
high pressure (heart pump), low pressure (venous system)
increasing pressure gradiant cause ____ flow?
which will go faster?
increasing
bottom differenc eof 75mmHg as opposed to 25
What is “flow”
Volume/amount of blood passing through a point per unit of time (mL/min)
Adult volumetric flow rate approximately 5000 mL/min (5 L/min)
Aka Cardiac output
Total blood volume circulates in approximately 1 min.
Volumetric Flow Rate (Q)
____ is determined by
pressure difference (Pressure gradient )
resistance to flow
Volumetric Flow Rate (VFR)
increase in pressure gradient = ____ VFR
increase in resistance = ____ VFR
what is the equation?
increased, decrease
VFR=pressure gradient/resistance
increase reistance = ___ flow
resistance is affected by (3)…
when we exercise, resistance _____. how?
decreased
viscosity, tube length, radius
decreases - radius increases = increased flow = (heart works harder) higher pressure gradient
remember VFR = pressure gradient/resistance
increased viscosity = _____ resistance = ___ flow
increased radius = ____ resistance = ___ flow
increased length = ___ resistance = ___ flow
increased, decreased
decreased, increased
increased, decreased
____ demonstrates the relationship between pressure, volume of flow and resistance.
is aka radius to the 4th power, which demonstates radius has a significant affect on ___ and ____
Applies to steady flow and straight tubes, not situation in body
Useful in describing increasing and decreasing flows
Volumetric Flow(Q)= Pressure Gradient x 3.14r4 8nL
Poiseuille’s Equation
resistance and flow
Increased PG = ____ Flow
Increased Diameter = ___ Flow
Increased Length = _____ Flow
variables in equation are
increase, increase, decrease
radius and length
According to Pousielles Equation, resistance increase is relative to the 4th power of the radius, so if you increase the radius 2x you will have ___ increase in flow? or is you decrease it to 1/2 you have ___ the flow
2˘4 = 16x
1/2 ˘4 = 1/16
___ determines ___ which determines ___
vasodilation =
vasoconstricton =
radius, resistance, flow
increase radius, decrease resistance, increase flow
decrease radius, increase resistance, decrease flow
at rest our legs are ___ b/c they don’t need ___
vasoconstricted, much blood
stenosis ____ radius, ___ resitance ___ flow
infection causes vessels to ____, ___ radius, ___ resistance, ____ flow
decrease, increase, decrease
vasodilate, increasing, decreasing, increasing to get blood to site to heal
what types of flow are there? (4)
Plug
Laminar
Disturbed
Turbulence
___ flow has the same flow speed throughout most vessel, Large vessels, Entrance of vessel
plug
___ flow
Streamlines parallel
Streamlines straight
Fastest in center
Slowest on outer edge
Parabolic (define) -
parabolic
sometimes word is interchanged w/ laminar. but not used often. it means speed on the side iis ~1/2 that in the center
slowest speed = ½ maximum
Nonparabolic laminar happens in body
____ flow means Streamlines are not straight
Happens at
Area of stenosis
Bifurcation
disturbed
also increased likelihood plaque will develop in these locations.
_____ flow is
Flow pattern is random and chaotic
Different speeds and directions
Eddies – area of flow reversal
Occurs at a channel widening, after a stenosis
What is Reynolds number?
Where does this happen?
turbulent
the point at which flow becomes spontaneously turbulent ~2000
*there are places that widen naturally like the buldb of the aortic arch so
can be result of natural, stenosis or aneurysm
Density, Viscosity, Diameter and Speed determine the point at which flow becomes _____
the sound this gives off is ____
when tissue vibrates due to this it is called ____
where might this occur
turbulent
bruit
tissue bruit
heart and proximal aorta
