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Cardio test 1-hemodynamics
Cardio test 1-hemodynamics
136
Dentistry
Graduate
03/28/2014

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Term
True or false

The heart serves as a single pump
Definition
False

The heart serves as a dual pump. The left heart or main pump and the right heart or boost pump
Term
What (2) ways can the heart be divided?
Definition
systemic and pulmonary

high pressure (left ventricles to systemic capillaries) and low pressure (right part through pulmonary circulation to relaxed left ventricle)
Term
What are the 3 fluid compartments of the body?
Definition
interstitial, intracellular and plasma (small amount of water)
Term
The total body water accounts for ___% of the body weight
Definition
60
Term
Blood is composed of formed elements and plasma, what is the main element?
Definition
red blood cells
Term
As blood passes through the capillaries, solutes exchange between the plasma and the interstitial fluid via process of ________.
Definition
diffusion
Term
Will you find a cell 20 microns away from a capillary?
Definition
No

Cells no further than 10 microns from capillary for diffusion
Term
Substances transported between organs via __________
Definition
convection
Term
Is blood distribution to the GI, skeletal, and skin static or varying?
Definition
varying (changes when exercise, after a meal, etc)
Term
Each side of the heart has two chambers, an atrium and ventricle connected by one-way valves called _________ valves
Definition
atrioventricular
Term
The rate at which blood is pumped from the heart (venous return in steady state) is called the _______ ________.
Definition
cardiac output
Term
True or false

Because the two sides of the heart operate in series, in steady state left output equals right output
Definition
True
Term
The rate the blood is returned to the vena cava is called ______ _______.
Definition
venous return
Term
Oxygenated blood fills the left ventricle via the ______ valve
Definition
mitral
Term
Blood is driven by the pressure of the contraction of the _________ into the aorta via the aortic valve and enters the arterial system. The amount of blood ejected per unit time is the cardiac output
Definition
ventricle
Term
The cardiac output is then distributed among the various organs to capillary networks via a ______ pathway. This distribution is not fixed and depends on the energy demands of the various target tissues.
Definition
parallel
Term
Blood is then collected from the organs into the veins and returned to the _____ _____.
Definition
vena cava
Term
Venous blood returns to the ______ atrium and through to the _____ ventricle via the ______ valve
Definition
right
right
tricuspid
Term
Blood is then ejected from the right ventricle through the ______ valve and carried via the _______ artery to the lungs
Definition
pulmonic

pulmonary
Term
Finally, blood is returned to the left atrium via the _________ vein
Definition
pulmonary
Term
In steady state, cardiac output is ~____ L/min
Definition
5
Term
A liquid within a container exerts a force on the walls of the container called ________. (units of _____ per unit of ______)
Definition
pressure

units of force per unit area
Term
_______ forces effects pressure within a fluid system where fluid at the bottom is compressed by the weight of the fluid above
Definition
gravitational
Term
The movement of fluid is termed ______, which is measured in units of volume/minute
Definition
flow
Term
True or false

As fluid flows each particle is moving at a infinite velocity
Definition
False

As fluid flows each particle is moving at a finite velocity
Term
As fluid flows through a tube, the mean velocity of flow must be (directly or indirectly) proportional to the flow rate and (directly or indirectly) proportional to the cross sectional area at that point.
Definition
As fluid flows through a tube, the mean velocity of flow must be directly proportional to the flow rate and indirectly proportional to the cross sectional area at that point.

V= Q/A (Q = flow rate, A= cross sectional area)
Term
In an _____ system there are no frictional resistances to resist flow.

In a ______ system, fluid particles interact and resist each others movement.
Definition
ideal

real
Term
In an ideal system, at rest the hydrostatic pressure exists as ________ energy.

Once fluid moves, some of this is converted to _______ energy
Definition
potential

kinectic
Term
In a real system, taking into account the frictional component, some of the energy is lost as ______ which cannot be converted back to kinetic or potential energy.

The end result is a drop in ______ along the length of the system
Definition
heat

pressure
Term
In an ideal system, the distribution of _________ is equal and is dependent on the ______ of flow.
Definition
forces (pressure)

velocity
Term
What is the equation for pressure of fluids at rest?
Definition
P = pgh

(P= pressure, p = density, g = acceleration due to gravity, h = vertical distance)
Term
What is the equation for the total energy of an ideal system?
Definition
Total energy = kinetic energy + potential energy
Term
What is the equation for the total energy of a real system?
Definition
Total energy = kinetic energy + potential energy + heat
Term
The blood flow through a given blood vessel depends on the (directly or indirectly) on the pressure difference between the two ends of the vessel and (directly or indirectly) on the resistance of blood movement.
Definition
The blood flow through a given blood vessel depends on the directly on the pressure difference between the two ends of the vessel (driving force) and indirectly on the resistance of blood movement (impedance to flow).
Term
What the factors that influence resistance?
Definition
Vessel radius and length, blood viscosity
Term
What is defined as the physical factors that govern blood flow.
Definition
hemodynamics
Term
We consider the (left or right) heart as a constant pressure generator that maintains a steady mean arterial pressure at its exit – namely the ______
Definition
left

aorta
Term
What is Ohm's law of electricity and how is it analogous to flow?
Definition
I= deltaV/R
(current (I) = voltage difference (deltaV) divided by the resistance)

F= deltaP/R
(Flow (F) = delta P divided by resistance for liquids)
Term
What is another name for deltaP?

driving pressure
perfusion pressure
pressure gradient
all of the above
Definition
all of the above
Term
True or false

For the flow of blood in a vessel, delta P is the is the pressure difference between any two points along the length of a given vessel.
Definition
true
Term
When describing flow in an organ, the pressure difference is generally between the _____ pressure and the _____ pressure
Definition
When describing flow in an organ, the pressure difference is generally between the arterial pressure (Pa) and the venous pressure (Pv)
Term
The magnitude of flow is directly proportional to the magnitude of the _______ difference or _____ (same word) gradient.

Blood flow is inversely proportional to _________
Definition
pressure

resistance
Term
The direction of flow is determined by the pressure gradient and blood will flow from (low to high or high to low) pressure
Definition
high to low
Term
The major mechanism for changing the flow of blood in the cardiovascular system is by changing the _______ of the blood vessels (particularly arterioles)
Definition
resistance
Term
True or false

The overall resistance across a circulatory bed results from the parallel or series arrangements of vascular branches and is governed by laws similar to those for electrical resistance in direct current
Definition
True
Term
It should be evident from the flow equation that the only way to alter blood flow through an organ is to alter the ______ across the vascular bed, or change the vascular _________.

Which is most often achieved?
Definition
pressure

resistance (most often achieved)
Term
The _______ and ______ have the highest pressure.
Definition
aorta and arteries
Term
The mean aortic pressure is about ____ mmHg in a normal individual
Definition
95
Term
True or false

The mean blood pressure falls a great amount as the blood flows down the aorta and through large distributing arteries
Definition
False

The mean blood pressure does not fall very much as the blood flows down the aorta and through large distributing arteries. It is not until the small arteries and arterioles that there is a large fall in mean blood pressure
Term
From the aorta and arteries, there is approximately ___-___% of the pressure drop along the vasculature occurs within the small arteries and arterioles

By the time blood reaches the capillaries the mean pressure may be ___-___ mmHg, depending upon the organ
Definition
50-70%

25-30
Term
The pressure falls or increases as blood travels into the veins and back to the heart.
Definition
falls
Term
Pressure within the thoracic ________ near the right atrium is very close to zero, and fluctuates from a few mmHg negative to positive with respiration.
Definition
vena cava
Term
The greatest blood volume resides in the (arterial or venous) vasculature, where 70-80% of the blood volume is found
Definition
venous
Term
Vein are referred to as _________ vessel because it holds 70-80% of the blood volume
Definition
capacitance
Term
The relative volume of blood between the arterial and venous sides of the circulation can vary considerably depending upon what 3 things?
Definition
total blood volume
intravascular pressures
vascular compliance.
Term
The major energy source for blood flow in the cardiovascular system is the _____.
Definition
heart
Term
There are higher pressures (higher resistance and lower compliance) in the systemic or pulmonary circuit
Definition
systemic
Term
During the contraction of the heart (systole) the heart ejects blood into the ______ raising the pressure.

During the relaxation phase (diastole) the ______ ______ declines
Definition
aorta

arterial pressure
Term
The _____ pressure is the difference between the systolic and diastolic pressure
Definition
pulse
Term
The _______ _______ pressure is given by the diastolic pressure + 1/3 pulse pressure.
Definition
mean arterial pressure (MAP)
Term
True or false

the mean arterial pressure is an average of the systolic and diastolic pressure
Definition
False

The mean arterial pressure is not a simple average of the systolic and diastolic pressure because a greater fraction of the cardiac cycle is spent in diastole than systole
Term
The pulsations in pressure in the great vessels are damped by the ____________.
Definition
microcirculation
Term
Vol/time is blood flow or blood flow velocity?
Definition
blood flow
Term
distance/time is blood flow or blood flow velocity?
Definition
blood flow velocity
Term
flow/cross sectional area is ________
Definition
velocity
Term
True or false

When the cardiac output is 5L/min, the flow the systemic capillaries is 7L/min due to the different velocities.
Definition
False

Regardless of the difference of velocities, when the cardiac output 5L/min, the flow through the systemic capillaries is also 5L/min. (slow velocity but high cross-sectional area)
Term
What is the importance of the slow flow through the capillaries?
Definition
it allows sufficient time for diffusional exchange
Term
Is there an inverse or direct relationship between blood flow velocity and cross-sectional area?
Definition
inverse

Maximal cross-sectional area and minimal flow rate in the capillaries
Term
Flow and pressure in the vasculature, especially the veins (hydrostatic pressure difference) are affected by _______.

We use the ______ as a reference point.
Definition
gravity

heart
Term
True or false

Pressures generated by hydrostatic columns are large when lying down and standing up.
Definition
False

Lying down, the pressures are determined by those generated by the heart pump because the vessels are at approximately the same height. Upon standing the pressures generated by hydrostatic columns become quite large
Term
What are (2) structural and functional mechanisms that exist to counteract the effects of gravity?
Definition
One way valves in the veins prevent the back flow of blood. The veins course through the skeletal muscles in the legs and when they contract they squeeze the veins, actively forcing the blood back to the heart. The muscle pump is very important and reduces venous pressure during exercise.
Term
Prolonged _______ can result in loss of consciousness – venous pooling
Definition
standing
Term
What are the 3 kinds of pressure difference in a blood vessel?
Definition
driving pressure
transmural pressure
hydrostatic pressure
Term
What type of pressure is between two points (axial pressure difference with the point of origin generated by the contraction of the heart) - Partery vs Pvein
Definition
driving pressure
Term
What type of pressure is a pressure drop across the vessel wall, determining the vessel diameter
Definition
transmural pressure
Term
What type of pressure arises when the vessel does not lie in the horizontal plane and is due to the density of blood and gravitational forces?
Definition
hydrostatic pressure
Term
True or false

The pressure gradient is determined by the input pressure only
Definition
false

the pressure gradient is determined both by the input pressure and the outflow pressure
Term
The relationship between the resistance, blood vessel diameter (or radius) and blood viscosity is described by the _________ equation
Definition
poiseuille
Term
What are 3 major determinants of resistance to blood flow?
Definition
qSize of the individual vessels (length and diameter)
Organization of the vascular network (series vs. parallel arrangements)
Physical characteristics of the blood (viscosity, laminar vs. turbulent flow)
Term
What is the MOST important factor of resistance to flow?

Is this factor directly or inversely proportional to resistance? By what power?
Definition
radius

inversely proportional to the 4th power of the radius of the vessel (radius decrease by half, resistance increase by 16x)
Term
The greater the vessel length, the greater or lesser the resistance?
Definition
greater

however as vessel length is constant, changes in length are not a physiological factor in the regulation of resistance
Term
The greater the viscosity, the greater or lesser the resistance to flow.

The prime determinant of blood viscosity is the ________
Definition
greater

hematocrit (plasma proteins and RBCs) ~40% of blood volume, but varies
Term
If the viscosity is too high, it is what disorder?

If it too low, it is what disorder?
Definition
Polycythemia

Anemia
Term
Will series or parallel circuits have a low resistance?
Definition
Parallel

series=high resistance
Term
In series or parallel circuits is it the sum of the individual resistance?
Definition
series (Total R greater than any of the individual resistances)
Term
In series or parallel circuits is it the sum of the reciprocal of the individual resistances?
Definition
parallel (Total R less than any of the individual resistances)
Term
Ideally, the blood flow in the cardiovascular system is laminar or turbulent flow?
Definition
laminar
Term
In laminar flow, is the highest velocity toward the vessel walls or in the center?
Definition
center (parabolic profile of velocity within the blood vessel bc blood adheres to the vessel walls)
Term
Up to a certain point there is a linear relationship between flow and driving pressure beyond which the flow becomes __________.
Definition
turbulent
Term
When an irregularity occurs in a blood vessel, e.g. at a valve or if there is a blood clot, blood flow is disrupted and becomes __________
Definition
turbulent
Term
Turbulent blood flow is accompanied by __________. Intense forms of turbulence can also be felt by ________.
Definition
murmurs

touch
Term
What does NOT promote turbulent flow?

decrease diameter
increase velocity
decrease blood viscosity
Definition
decrease diameter

(an increase of diameter promotes turbulent flow)
Term
A _________ valve causes a narrowed valve

An ________ valve results in back flow

Both of these cause ______,
Definition
stenotic

insufficient

murmurs (caused by turbulent flow)
Term
What is the ability of a vessel to distend and increase volume with increasing transmural pressure (inside minus outside pressure) = change in volume/ change in pressure?
Definition
compliance
Term
For compliance, the slope is not linear because the blood vessel wall is a heterogenous or homogenous tissue?

Therefore, compliance (decreases or increases) at higher pressure and volumes?
Definition
heterogenous

decreases (vessels become "stiffer" at higher pressures and volumes)
Term
At lower pressure, the compliance of a vein is (greater, lesser, or equal) than an artery?

At higher pressures, venous compliance is (greater, lesser, or equal) than an after?
Definition
greater (veins can accommodate a large changes in blood volume with only a small change in pressure)

equal/similar (An increase in vascular tone, which causes contraction, decreases compliance)
Term
True or false

As the heart pumps part of the work goes to expanding the arteries
Definition
True

At the end of systole and throughout diastole, the previously stretched arteries recoil and impart energy that serves to propel the blood.
Term
The tension in the walls of arteries and veins is a classical example of the Law of ______
Definition
Laplace
Term
The Law of Laplace applied to a tube says that for any given internal fluid pressure, the wall tension will be proportional to the _______ of the vessel
Definition
radius
Term
The implication for the Law of Laplace is that an artery of twice the radius must be able to withstand twice the ____ ____
Definition
wall tension
Term
At the region where the aneurysm occurs, the pressure (increases, decreases or remains the same) but the radius will (increase, decrease, or remain the same) and the wall tension (increases, decreases, or remain the same).

The greater the wall tension, the greater the likelihood of _________
Definition
At the region where the aneurysm occurs, the pressure remains the same but the radius will increase and the wall tension increases

rupture
Term
The initial peripheral vascular disease process is ________ which results in arterial stenosis and occlusions in the arteries supplying the muscles of the lower extremities. Blocked flow causes pain and numbness, in severe cases can cause gangrene.
Definition
atherosclerosis
Term
Peripheral vascular disease causes hemodynamic changes with causes reduced ___________ and ________
Definition
limb pressure
flow
Term
Cardiac excitation-contraction coupling is the process by which an electrical event causes an (increase and decrease) in [Ca2+]i which then translates into muscle contraction and pumping of blood.
Definition
increase
Term
As a depolarizing wave reaches a _______ (cell) this causes an action potential to fire in a neighboring cell
Definition
myocyte
Term
The upstroke of the action potential is caused by inward _____ (ion) movement. As the sarcolemma depolarizes, this activates ________ channels
Definition
The upstroke of the action potential is caused by inward Na movement. As the sarcolemma depolarizes, this activates voltage gated Ca channels
Term
During depolarization, Ca flows into the cell and activates the _________. This is known as _____________.

Reverse mode ________ activity also causes the influx of Ca.
Definition
RyR (Ryanodine receptor-class of intracellular Ca channel)
Calcium Induced Calcium Release (CICR)

NCX (Sodium-Calcium Exchanger)
Term
During depolarization, Ca binds to ___________ which turns on the contractile machinery.
Definition
troponin C
Term
In ventricular myocytes, the predominant Ca channel type is the ______ Ca channel - activated by depolarization
Definition
L type
Term
As the Ca concentration rises inside the cleft, Ca-dependent inactivation of the voltage gated Ca channel (______ receptor) occurs and this causes the channel to close down.
Definition
DHP
Term
Sarcoplasmic release of Ca2+ is via _______
Definition
ryandoine receptor (RyR)
Term
_______________ (cytosolic) limits Ca2+ entry during an action potential
Definition
Cytosolic Ca2+-dependent inactivation
Term
NCX exchance ____ (#) Na3+ for 1 Ca2+.
Definition
3
Term
A high intracellular concentration favors (inward or outward) currents via NCX and a positive membrane potential favors (inward or outward) currents via the transporter.
Definition
A high intracellular concentration favors inward currents via NCX and a positive membrane potential favors outward currents via the transporter.
Term
For relaxation to occur, the [Ca2+] of the cytosol must (increase or decrease)?
Definition
decrease (in order for Ca to dissociate from troponin)
Term
What are 4 way to remove Ca?
Definition
1. Sarcoplasmic reticulum Ca2+-ATPase (SERCA)
2. Sarcolemmal Na+-Ca2+ exchange (NCX)
3. Sarcolemmal Ca-ATPase (PMCA)
4 Mytochondrial Ca uniporter
Term
In heart failure SERCA pump will (increase or decrease) and Na+/Ca2+ exchangers (increases or decreases) and these systems then contribute almost equally (reduces the amount of SR Ca2+)
Definition
In heart failure, the SERCA pump will decrease in activity, but the Na/Ca exchanger increases in activity- until they start to contribute equally.
Term
True or false

Ca2+ extrusion must be less than Ca2+ influx
Definition
False

Ca2+ extrusion must balance Ca2+ influx
Term
True or false:

Contraction of cardiac muscle absolutely requires influx of Ca2+ from the extracellular milieu
Definition
True
Term
What are the 3 ways to change the strength of cardiac contraction?
Definition
1. Alter the amplitude or duration of the Ca2+ transient

2. Alter the sensitivity of the myofilaments to Ca2+
Upon stretch as the heart fills with blood, the myofilament Ca2+ sensitivity is enhanced (autoregulatory mechanism: The Frank-Starling response).

3. Phosphorylation of Troponin I (increase crossbridge cycling)
Term
What is the intrinsic ability of the myocyte to develop force.
Definition
Contractility (inotropism)
Term
Agents that increase contractility have a (positive or negative) inotropic effect and those that decrease contractility have a (positive or negative) inotropic effect.
Definition
Agents that increase contractility have a positive inotropic effect and those that decrease contractility have a negative inotropic effect.

Both rate of tension development and peak tension are considered.
Term
Contractility correlates with [Ca2+ ]i which depends upon what 2 things?
Definition
inward passive Ca2+ current upon depolarization

amount of Ca2+ released from the SR
Term
G-proteins are linked to adenylyl cyclase that dephosphorylates ATP to form ___________
Definition
cAMP
Term
cAMP activates _______ (which goes on to phosphorylate the calcium channels and ryanodine receptor = increase calcium influx into cell and decrease calcium efflux from the SR)
Definition
PKA
Term
Gs-protein activation (increases or decreases) heart rate

Gi-protein activation (increases or decreases) heart rate
Definition
increases

decreases
Term
______ activation (e.g., via adenosine and muscarinic receptors) decreases cAMP and protein kinase activation
Definition
Gi
Term
Stimulation of the sympathetic nervous system and an increase in circulating catecholamines have a (positive or negative) inotropic effect
Definition
positive
Term
Stimulation of the parasympathetic nervous system has a (positive or negative) inotropic effect
Definition
negative
Term
Increase in peak tension (due to increase of L-type Ca2+ channel activity and enhanced CICR), Increase in rate of tension development (effect on contractile machinery), and Faster rate of relaxation (via activity of phospholamban)

sympathetic or parasympathetic?
Definition
sympathetic
Term
Decrease in peak tension due to inhibition of L-type Ca2+ channels and activation of IKACh which shortens the plateau phase of the action potential. Thus, the amount of Ca2+ that can enter the cell is reduced and thus CICR is reduced

sympathetic or parasympathetic
Definition
parasympathetic
Term
An increase in heart rate leads to an (increase or decrease) in contractility?
Definition
increase
Term
When there is an increase in heart rate, there is an (increase or decrease) in Ca2+ influx and an (increase or decrease) in Ca2+ sequestered into the SR
Definition
increase

increase
Term
Cardiac glycosides are (positive or negative) inotropic agents?
Definition
positive
Term
Cardiac glyosides (activate or inhibit) Na-K ATPase (Na+ pump).

By doing so, intracellular Na+ concentration (decreases or increases) inside the cell.

This (decreases or increases) NCX activity (following a decrease in Na+ gradient) which (decreases or increases Ca2+ concentration inside the cell which (increases or decreases) tension?
Definition
inhibit Na-K ATPase

intracellular Na+ concentration increases

decrease NCX

Increase Ca2+

increase tension
Term
What is used to treat congestive heart failure that increases the force of contractility?
Definition
cardiac glycosides
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