NYCC Systems Physiology Heart: Vascular Function and Blood Flow Flashcards

Terms Definitions
What are the atrial and ventricular syncytiums?
Networks of cardiac muscle cells connected by intercalated discs that aid in coordinated contraction
What are the specialized excitatory and conductive muscle fibers of the heart?
Sinuatrial (S-A) nodal fibers, Atrioventricular (A-V) nodal fibers, A-V bundle
What is the Frank-Starling mechanism?
Within physiologic limits, the heart pumps all of the blood that returns to it by the way of veins
Cardiac output = ___ x ___
Heart rate (HR); Stroke volume (SV)
Stroke volume = End-_____ volume - End-_____ volume.
Diastolic; Systolic
At the end of diastole, the heart is finished _____.
At the end of systole, the heart is finished _____.
If the end-diastolic volume is 120 ml and the end-systolic volume is 50 ml, what are the stroke volume and ejection fraction?
SV = 70 ml, EF = 60%

(EF = 70/120)
Cardiac output = __ beats/min x __ ml/beat = _____ ml/min.
72; 70; 5040
At rest, the heart pumps __-__ L/min of blood.
The heart is controlled by _____ and _____ nerves.
Sympathetic; Parasympathetic
Cardiac muscle has _____ and _____ filaments and _____ resistance _____ disks (_____ the resistance of cell membrane.)
Actin; Myosin; Low; Intercalated; 1/400
Cardiac muscle has _____ _____ network per _____ located at the level of the _____.
One T-tubule; Sarcomere; Z disc
Skeletal muscle has _____ _____ networks per _____ located near the ends of the _____ filaments at the _____ band junctions.
Two T-tubule; Sarcomere; Myosin; A-I
Smooth muscle has _____, but no _____, _____, _____ or _____.
Caveoli; T-tubules; Troponin (calmodulin); Tropomyosin
What are caveoli?
Specialized invaginations in smooth muscle
Resting membrane potential of cardiac muscle is ___ to ___ millivolts.
-85 to -95
Action potential of cardiac muscle is ___ milivolts with an upstroke of +___ millivolts
105; 20
Plateau lasts ~___-___ seconds in ventricular muscle (much longer than _____ muscle)
0.2-0.3; Skeletal
Ventricular muscle action potential phases:
0: Fast ___ channels open then slow ___ channels open
1: ___ channels open
2: ___ channels open more
3: ___ channels open more
4: _____ _____ potential
Na+; Ca++; K+; Ca++; K+; Resting membrane
During the refractory period, cardiac muscle cannot be _____.
The refractory period lasts ___-___ seconds in the ventricles.
The refractory period lasts ___ seconds in the atria.
Ca++ is released from the _____ _____ and the _____ as a result of action potential.
Sarcoplasmic reticulum; T-tubules
As a result of the action potential, _____ Ca++ depends strongly on _____ Ca++ concentration.
T-tubule; Extracellular
As a result of the action potential, _____ bind Ca++ for storage inside the _____.
Mucopolysaccharides; T-tubules
Is Ca++ defiency detectable by blood testing?
In excitation coupling:
1. The action potential: moves along the _____.
2. ___ receptors are activated.
3. ___ binds to the _____ receptor which opens releasing much ___.
4. Calcium is pumped back into the _____ _____ and back into the _____.
5. Contracti
1. T-tubule
2. DHP
3. Ca; Ryanodine; Ca
4. Sarcoplasmic Reticulum; T-tubule
5. Terminated
What is the major difference between excitation coupling in skeletal muscle and in cardiac muscle?
Skeletal muscle sarcoplasmic reticulum release is triggered by Voltage.
Cardiac muscle sarcoplasmic reticulum release is triggered by Calcium.
The sympathetic aspect of the ANS _____ heart rate from 72 bpm to ___-___ bpm.
Increases, 180-200
The sympathetic response of the ANS _____ force of heart contraction ___x normal.
Increases, 2
The sympathetic response of the ANS can _____ cardiac output by more than ___%.
Increase, 100
The parasympathetic (vagal; vasovagal) response of the ANS _____ heart rate from 72 bpm to ___-___ bpm.
Decreases; 30-40
The parasympathetic (vagal; vasovagal) response _____ force of heart contraction ___% to ___%
Decreases; 20; 30
The parasympathetic (vagal; vasovagal) response can _____ cardiac output by ___% or more.
Decrease; 50%
Sympathetic mechanism effects:
_____ release
Increased permeability of ___ & ___
_____ of S-A node, A-V node, A-V bundles
_____ of cardiac (ventricular) muscle
Increased permeability of _____ contributes to exciting the contractile process of _____ __
Norepinephrine; Na+ & Ca++, Depolarization; Depolarization; Ca++; Cardiac myofibrils
The main sympathetic effect mechanism is a(n) _____ in _____ _____.
Increase; Contractile strength
Parasympathetic mechanism effects:
Fiber distribution: _____ _____ and _____ _____.
_____ release
Increased permeability of ___.
Decreased rate of rhythm of _____ _____ fibers.
_____transmission of cardiac impulses into _____ from the _____ node (_____ fa
S-A node; A-V node; Acetylcholine; K+; S-A node; Slowed; Ventricles; A-V; Safety
Parasympathetic effect mechanisms?
1. Decreased rate of rhythm of _____ node fibers
2. Slowed transmission of _____ node cardiac impulses into the ventricles
In _____ muscle, maximal active stress is developed at normal resting length; ~__ microns.
Skeletal; 2
Cardiac muscle normally operates at lengths ______ optimal length.
Excess ___ decreases contractility and slows the heart rate.
Excess ___ causes spastic contraction.
Low ___ causes cardiac flaccidity.
The _____ _____ is the series of mechanical events from the beginning of one heartbeat to the next.
Cardiac cycle
The cardiac cycle begins with _____ generation of a(n) _____ _____ in the ___ node that is propagated through the heart via the _____system.
Spontaneous; Action potential; S-A; Conducting
The _____ contract first and function as _____ _____ for the ventricles.
Atria; Primer pumps
What is the period of relaxation where the heart fills with blood?
What is the period of contraction of the heart?
There are _____, _____, and _____ events associated with the cardiac cycle.
Volume, Pressure, Electrical
The ECG (EKG) monitors the _____ events that result in a _____ event (_____)
Electrical; Mechanical; Contraction
What does the P wave signify?
Depolarization of the atria
What does the QRS wave signify?
Depolarization of the ventricles
What does the T wave signify?
Repolarization of the ventricles
___% of blood returning to heart flows through _____ into ventricles prior to _____ contraction.
80; Atria; Atrial
_____ contraction causes the additional ___% of ventricle _____.
Atrial; 20; Filling
Under most conditions, the heart can operate without the 20% of blood added by _____ _____.
Atrial contraction
Atrial failure may not be noticed unless the patient _____; then acute signs of heart _____ may develop along with _____ of _____.
Exercises, Failure, Shortness; Breath
What does the a-wave signify?
Atrial contraction
What does the c-wave signify?
Ventricular contraction; AV valve bulges as pressure increases in ventricle
What does the v-wave signify?
Slow flow of blood into atria while AV valves are closed
The a-, c-, and v-waves are part of the _____ _____ _____.
Atrial pressure curve.
During ventricular diastole, ___ valves open and the _____ fill with blood.
AV; Ventricles
During the ___1/3 of ventricular diastole, the ventricles fill rapidly.
During the _____ 1/3 of ventricular diastole a small amount of blood flows into the ventricles; _____.
Second; Diastasis
During the _____ 1/3 of ventricular diastole the atria contract and fill ___% of ventricle volume.
Third (Last); 20
Cardiac cycle 1 - Ventricular systole begins:
_____ contraction begins
_____ pressure rises
_____ valves close
_____ and _____ valves open against pressure in aorta and pulmonary artery
_____ is occurring (_____ increasing) but no ventricular _____ has oc
Isovolumic; Ventricular ; AV; Aortic; Pulmonary; Contraction; Tension; Emptying
Cardiac cycle 2 - Ejection phase:
_____ ventricular pressure > ___ mm Hg and _____ valves open
Blood pours out of _____ ; ___% in first ___ of ejection phase (_____ ejection)
Remaining ___% is ejected in last ___ of phase (___ ejection)
Left; 80; Semilunar; Ventricles; 70; 1/3; Rapid; 30; 2/3; Slow
Cardiac cycle 3 - End of systole:
_____ relax allowing _____ pressures to decrease rapidly.
Elevated _____ pressure pushes some blood back toward _____ closing _____ valves.
_____ continue to relax though ____ volume does not change (_____ relaxation)
Ventricles; Intraventricular; Arterial; Ventricles; Semilunar; Ventricles; Ventricular; Isovolumic; Intraventricular; Diastolic; AV
During diastole, ventricle volume rises to ~___ to ___ ml; the _____-_____ volume
110; 120; End-diastolic
As ventricles empty in systole, volume decreases about ___ml; the _____ volume.
70; Stroke
The remaining volume of the ventricles (40 - 50 ml) is the _____-_____ volume
The fraction of end-diastolic volume that is ejected is the _____ _____; usually ___% of total volume.
Ejection fraction; 60
_____ _____ volume minus _____ _____ volume = stroke volume
End diastolic; End systolic
(_____ volume / _____ _____ volume) = ejection fraction
Stroke; End diastolic
If the stroke volume is 70 ml and the heart rate (HR) is 70 beats/minute, what is the cardiac output?
=HR x Stroke volume
=70/min x 70 ml
=4900 ml/min
Cardiac cycle - Aortic pressure curve:
Pressure in the aorta _____ during systole after the _____ valve opens to ~ ___ mm Hg (systolic pressure)
_____ of arterial walls maintains pressure as the valve closes.
_____ (dicrotic notch occurs in the curve when
Increases; Aortic; 120; Elasticity; Incisura; Aortic; Backflow; Backflow; Decreases; Ventricle; 80; Diastolic
What causes the heart sounds?
Valve closure and the resulting pressure changes
What causes the first heart sound?
Closure of the atrioventricular valves

(the "lub" of the "lub-dup")
What causes the second heart sound?
Closure of semilunar (aortic & pulmonary) valves

(the "dup" of the "lub-dup")
What causes the third heart sound?
Rapid filling of the ventricles
What are the 3 determinants of myocardial performance for the left ventricle?
Preload, Afterload, Contractility
Preload is the _____ _____ volume; _____ _____ when the _____ ventricle begins contraction
End diastolic (120 ml); Muscle tension; Left
What is afterload?
Aortic pressure
What is contractility?
(change in length / change in time)
What is active myocardial length-tension (Frank-Starling) determined by?
Overlapping of actin & myosin and shifts with changes in contractility
Passive length-tension is due to _____ of _____ _____.
Stretching; Cardiac tissue
Increase in preload provides better _____-_____ overlap resulting in more _____ force.
Actin-myosin; Contractile
Afterload determines how much _____ is used to generate _____ and how much _____ is used for shortening.
Force; Pressure; Force
Changes in contractility provide a _____-independent mechanism to increase _____ force.
Preload; Contractile
Myocardial _____ enhances myocardial performance.
Increase in end-diastolic pressure (e.g., increased venous return) causes an increase in _____ _____ development and consequently increases _____ _____ of the heart.
Ventricular pressure; Pumping ability
What is the Frank-Starling law?
Within physiological limits, the heart pumps all blood returned to it by the veins.
Increasing initial fiber length causes more _____ _____, but does not increase _____.
Forceful contraction; Contractility
Afterload affects _____ and the onset of _____.
Contractility; Shortening
What is the major proportion of energy to move blood for low-pressure veins to the high-pressure arteries?
Volume-pressure work (external work)
What is the minor proportion of energy to accelerate blood to the ejection velocity through the valves?
Kinetic energy of blood flow
Volume-pressure curve - Period of filling:
Ventricle is in _____
Atrial pressure exceeds _____ pressure and AV (mitral) valve opens
_____ of blood in ventricle increases, atria _____ to add last ___% of volume
_____-_____ volume is reached
Diastole; Ventricular; Volume; Contracts; 20; End-diastolic
Volume-pressure curve - Isovolumic contraction:
_____ and _____ valves closed
_____ contracts; increasing pressure
Ventricular pressure exceeds _____ pressure and _____ valve opens (~ ___ mm Hg)
AV; Aortic; Ventricle; Aortic; Aortic; 80
Volume-pressure curve - Ejection:
_____ continues to contract
_____ pressure continues to increase
_____ decreases as blood is pushed into _____ (ejection fraction)
_____-_____ volume is reached; not all blood is pumped out of _____ (___ - ___ ml remain)
Ventricle; Systolic; Volume; Aorta; End-systolic; Ventricle; 40 - 50
Volume-pressure curve - Isovolumic relaxation:
_____ valve closes as _____ pressure falls below _____ pressure
Relaxation continues with no change in _____
_____ pressures fall below _____ pressure and AV valves _____; cycle begins again
Aortic; Ventricular; Aortic; Volume; Ventricular; Atrial; Open
For _____, preload is considered the _____-_____ volume when ventricles are filled.
Contraction; End-diastolic
Afterload of the _____ is the pressure in the _____.
Ventricle; Aorta
Increased _____ stimulation of the heart or cardiac _____ result in an increase in contractility.
Sympathetic; Hypertrophication (e.g., from marathon training)
What are the two basic means by which volume of blood pumped by the heart is regulated?
Frank-Starling mechanism (intrinsic regulation), Control of heart rate and strength of pumping by the ANS (extrinsic regulation)
The Frank-Starling mechanism describes the _____ ability of the heart to adapt to increasing _____ of inflowing blood.
Intrinsic; Volumes
The greater the heart is _____ during filling, the greater the force of _____ and _____ of blood pumped into the aorta.
Stretched; Contraction; Volume
What 3 things does sympathetic stimulation increase?
Heart rate, Force of contraction (so increased volume of blood pumped and ejection pressure), Cardiac output
What 3 things does parasympathetic stimulation decrease?
Heart rate (b/c vagal fibers innervate the atria), Strength of heart muscle contraction, Ventricular pumping (b/c of first two)
Changes in _____ _____ from _____ _____ _____ stimulation result from changes in heart rate and contractile strength of the heart.
Cardiac output; Autonomic nervous system
Intrinsic spontaneous rate of _____ _____ depolarization is dominated by _____ innervations from the _____ using _____ as a transmitter.
Sinuatrial node; Parasympathetic; Vagus (CN X); ACh
ACh slows _____ _____ _____ and lowers _____ _____.
Sinuatrial node depolarization; Heart rate
Nodal areas have high _____ _____ activity so the transmitter is cleared rapidly.
ACh esterase
Sympathetic fibers originate from _____ _____ ganglia and primarily innervate the _____ _____.
Sympathetic chain; Sinoatrial node
_____ is the transmitter which increases heart rate.
Elevated _____ and _____ can act directly on the SA node to increase the heart rate.
Temperature; Stretch
Sympathetics also innervate the _____ _____ where norepinephrine increases _____ _____.
Atrioventricular node; Conduction velocity
The sinus (sinuatrial) node is a specialized _____ located in the _____ _____ wall of the _____ atrium just _____ and _____ to opening of _____ vena cava.
Muscle; Superior Posterior Lateral; Right; Below; Lateral; Superior
The sinus (sinuatrial) node contains almost no _____ filaments, however nodal fibers connect directly with _____ muscle fibers.
Contractile; Atrial
_____ _____ that begin in the sinus (sinuatrial) node spread immediately into the _____ muscle wall.
Action potentials; Atrial
The conducting system has the capability of _____-_____ that results in automatic _____ _____ and _____.
Self-excitation; Rhythmical discharge; Contraction
The sinus (sinoatrial) node has the capability of _____-_____ and it will _____ the rate of the heart beat.
Self-excitation; Control
Resting membrane potential of _____ fibers is _____ negative (-55 to -60 mv) in comparison to _____ muscle (-85 to -90 mv)
Nodal; Less; Ventricle
Cell membranes of nodal fibers are leaky to _____ and _____ ions that _____ intracellular negativity.
Na+; Ca++; Neutralize
Differences in the functioning of _____ _____ in the nodal fibers are due to less negative resting potential.
Ion channels
Fast _____ channels cause upstroke of action potential from ~-90 mv as _____ enters the cell.
Slow _____-_____ channels create the plateau of the action potential.
Na+; Ca++
Opening of _____ channels allowing outflow of _____ ions returns membrane potential to resting levels.
K+; K+
Action potentials begin at a less negative _____ _____ (-55 mv, and some _____ channels are blocked or inactivated.
Resting potential; Na+
High _____ ion concentration outside of _____ fibers with open channels results in _____ ions leaking into fiber and a slow rise in the _____ potential in a _____ direction.
Na+; Nodal; Na+; Resting; Positive
At the threshold voltage of ___ mv, slow Na+ - Ca++ channels _____ causing the _____ potential, which is _____ to develop than the _____ potential in the muscle fiber.
-40 mv; Open; Action; Slower; Action
What does the inherent leakiness of the sinus nodal fibers to Na+ and Ca++ ions cause?
Self-excitation of the sinus nodal fibers
Return to the _____ state occurs more _____ in sinus nodal fiber when compared to the ventricular muscle fiber.
Resting; Slowly
_____ channels remain _____ a few tenths of a second resulting in excess negativity (_____) of the nodal fiber to -55 to -60 mv at the termination of the _____ potential when the _____ channels _____.
K+; Open; Hyperpolarization; Action; K+; Close
The action potential generated in the sinus node spreads outward in specialized _____ of _____ fibers.
Bands; Atrial
What band goes through the anterior wall of the atrium into the left atrium?
Anterior interatrial band
What internodal pathways traverse the atria and terminate in the AV node?
Anterior, Middle, Posterior
The anterior, middle, and posterior internodal pathways traverse the _____ and terminate in the _____ node.
Atria; Atrioventricular (AV)
The internodal pathways have an inherent conduction delay (0.03 sec) of the cardiac impulse that allows time for the _____ to _____ blood into the _____ before _____ contraction begins.
Atria; Empty; Ventricles; Ventricular
The atrioventricular node and its adjacent conductive fibers delay the _____ impulse transmission into the _____.
Cardiac; Ventricles
What two structures delay the cardiac impulse transmission into the ventricles?
Atrioventricular (AV) node, Adjacent conductive fibers
Where is the atrioventricular (AV) node located?
Posterior wall of the right atrium
What do the fibers of the atrioventricular (AV) bundle penetrate?
Fibrous tissue between atria and ventricles
The _____ portion of the atrioventricular (AV) bundle divides into the _____ and _____ _____ branches.
Distal; Left; Right bundle
How long is the total delay in the atrioventricular (AV) nodal and bundle system?
0.13 sec
There is a one-way _____ through the atrioventricular (AV) bundle that prevents the _____ from traveling backward from ventricles to atria.
Conduction; Impulse
A _____ barrier exists between the _____ tissue of the atria and the ventricles such that the atrioventricular (AV) node and bundle system is the only means of _____ _____ between atria and ventricles.
Fibrous; Muscle; Impulse conduction
Purkinje fibers lead from the _____ _____ through the _____ _____ into the _____.
Atrioventricular (AV) node; AV bundle; Ventricles
Purkinje fibers are _____ diameter fibers.
Purkinje fibers have _____ permeability at the _____ junctions.
High; Gap
After Purkinje fibers penetrate the _____ barrier, they transmit the action potential ___x faster than the _____ muscle.
Fibrous; 6; Ventricular
Purkinje fibers transmit the action potential _____ through the ventricles.
Purkinje fibers penetrate ___ of the way into the ventricle wall and become continuous with _____ _____.
1/3; Muscle fibers
The sinus node controls heart beat because its _____of _____ is faster than that of other parts of the heart.
Rate of discharge
List the range of rates of discharge:
Sinus node
AV node
Purkinje fibers
70 - 80 / min
40 - 60 / min
15 - 40 / min
A pacemaker elsewhere than the sinus node is called an _____ pacemaker.
An ectopic pacemaker causes abnormal _____ of _____ and affects heart _____.
Sequence of contraction; Pumping
What is the condition where impulse from the sinus node to the heart is blocked and the AV node or bundle becomes the pacemaker?
Sinoatrial Block
What is the condition where impulse from the atria to ventricles is blocked?
Atrioventricular (AV) block
during an AV block, the atria beat normally with _____ _____ impulse and the _____ _____ in the ventricles becomes the pacemaker
Sinus node; Purkinje system
What is the syndrome which follows a sudden AV block where impulses are not conducted and a delay of about 5 - 20 seconds occurs before the ventricles contract?
Stokes-Adams syndrome
What may result from Stokes-Adams syndrome?
Fainting; Death
In Stokes-Adams syndrome, what part of the heart becomes the pacemaker?
Purkinje system--usually distal AV node or bundle
Parasympathetics (from ______) are distributed mainly to the _____ and _____ _____, and to a lesser extent, the muscle of the _____ and, lesser still, the _____ muscle.
Vagus (CN X); Sinus; AV nodes; Atria; Ventricular
Sympathetics (from _____ _____ _____) are distributed to _____ parts of the heart, with strong innervations to _____ and other areas.
Sympathetic chain ganglia; All; Ventricles
Vagal stimulation releases _____ into the heart.
Acetylcholine _____ rate and rhythm of the _____ node and _____ the excitability of the _____ junctional fibers between _____ musculature and the _____ node. _____ transmission of the cardiac impulse into the _____.
Decreases; Sinus; Decreases; Atrioventricular (AV); Atrial; AV; Slowing; Ventricles
Weak to moderate _____ stimulation slows the rate of heart pumping.
Strong vagal stimulation can block signal transmission from _____ to _____ _____.
Sinus; Atrioventricular (AV) nodes
Strong vagal stimulation may cause the ventricles to stop beating for 5 - 20 seconds after which part of the Purkinje stem (AV bundle) establishes a rhythm of ventricular contraction ~ 15 - 40 bpm. What is this called?
Ventricular escape
Sympathetic stimulation releases _____ and _____ overall activity of the heart.
Norepinephrine; Increases
Sympathetic stimulation:
Increases rate of _____ _____ discharge.
Increases rate of _____ and _____ in all of the heart.
Increases _____ of _____ in all cardiac muscle
Sinus node; Conduction; Excitability; Force of contraction
The increased force of contraction from sympathetic stimulation may be due to increased _____ of fibers to _____ and _____ ions.
Permeability; Na+; Ca++
The electrocardiogram (ECG) is composed of _____, _____ and _____.
Waves; Segments; Intervals
What are the three major waves on a lead I electrocardiogram?
P wave, QRS complex, T wave
P wave signifies _____ _____.
Atrial depolarization
QRS complex signifies _____ _____.
Ventricle depolarization
T wave signifies _____ of _____.
Repolarization of ventricles
P wave immediately precedes _____ contraction.
QRS complex immediately precedes _____ contraction.
Ventricles remain _____ until a few msec after the end of the T _____ wave.
Contracted; Repolarization
Atria remain contracted until they _____; but this wave is obscured by the _____ wave.
Repolarize; QRS
What is the time between the beginning of the P wave and the beginning of the QRS complex?
P-Q or P-R interval
The P-Q or P-R interval represents the time between the beginning of _____ of the atria and of the ventricles.
The Q-T interval represents the time from the _____ of the Q wave to the _____ of the T wave.
Beginning; End
The Q-T interval approximates the time of _____ contraction.
What are the sections of baseline between two waves called?
What are the segments on the lead 1 tracing of the ECG?
P-R Segment, S-T Segment
An ECG (is/is not) the same as a single action potential.
Is not
The action potential is _____ electrical event in a _____ cell.
One; Single
ECG is a(n) _____ recording that represents the sum of multiple _____ _____ taking place in many cardiac cells.
Extracellular; Action potentials
An ECG is an electrical "view" of a _____ object.
ECG provides info on _____ _____, _____, _____ _____, and _____ of _____ in the heart.
Heart rate; Rhythm; Conduction velocity; Condition; Tissues
during depolarization the normal _____ potential inside the cardiac muscle fiber reverses and becomes slightly _____ inside and _____ outside.
Negative; Positive; Negative
In an ECG, complete _____ has both electrodes reading a negative potential.
In an ECG, _____ has positivity returning to the outside of the fiber.
In an ECG, complete _____ has both electrodes reading a positive potential.
What is the heart rate?
Time between two successive heart beats
Heart rate is normally timed from the beginning of one ___ peak to the next (the ___-___ interval).
R; R-R
If the timed R-R interval is 1.0 second, the heart rate is ___ bpm.
Commonly, the heart interval is ___ sec, resulting in a heart rate of ___ bpm.
0.83; 72
What type of circulation serves all tissues except lungs?
Systemic (Peripheral)
What type of circulation serves the lungs?
Systemic (Peripheral) Circulation contains ___% of blood volume (___% in veins, ___% in arteries, ___% in arterioles and capillaries).
84; 64; 13; 7
Pulmonary circulation contains ___% of blood volume (heart contains ___%, vessels contain ___%)
16; 7; 9
What types of vessels have the largest area and function in storage?
Velocity of blood flow is _____ proportional to cross-sectional area.
Blood pressure is highest in _____ and decreases continuously as blood flows through the system.
Blood pressure decreases as energy is lost as a result of _____ to flow by vessels and friction between blood _____.
Resistance; Cells
Highest blood pressure is in the _____ of ___ mm Hg during ventricular _____ (_____ pressure)
Aorta; 120; Systole; Systolic
Blood pressure falls to a low of ___ mm Hg during ventricular _____ (_____ pressure)
80; Diastole; Diastolic pressure
What type of blood pressure reflects driving pressure created by the pumping of the heart.
What type of blood pressure reflects ventricular pressure?
What is used to represent the driving pressure for blood flow?
Mean Arterial Pressure (MAP)

= diastolic P - 1/3 (systolic P - diastolic P)
For a person at rest whose systolic pressure is 120 and diastolic pressure is 80, what is the mean arterial pressure?
MAP = 80 + 1/3 (120 - 80)
MAP = 93 mm Hg
Mean arterial pressure is closer to _____ pressure because _____ lasts twice as long as _____ at rest (60 - 80 bpm).
Diastolic; Diastole; Systole
Arterial pressure is a _____ of flow _____ and _____ of the arteries.
Balance; In; Out
Blood flow into the aorta is equal to the _____ _____.
Cardiac output (CO)
Blood flow out of arteries is _____ by _____ _____ (flow at arteriolar level).
Influenced; Peripheral resistance

(MAP is proportional to CO x R of arterioles)
If _____ _____ increases, more blood is pumped into arteries.
Cardiac output
If cardiac output increases and _____ does not change, blood volume in arteries _____ and so does arterial pressure.
Resistance; Increases
If cardiac output is _____ but resistance _____. flow in is the same but flow out is less, so arterial blood volume and pressure _____.
Unchanged; Increases; Increases
The rate of blood flow to tissues is controlled in relation to _____ _____.
Tissue needs
Active tissues need increased supply of _____.
Increase _____ _____ has its limits, therefore increasing blood flow to the entire body is not possible when some tissues are _____.
Cardiac output; Active
Microvasculature monitors tissue needs and _____ or _____ as needed.
Constricts; Dilates
Cardiac output is mainly controlled by _____ _____ flow.
Local tissue
The heart responds automatically to blood returning to it through the _____ _____ and pumps it through the system.
Vena cava
The heart responds to the _____ of the tissues.
The ANS assists in _____ heart pumping and blood flow.
The ANS can _____ arterial pressure _____ from either local blood control or cardiac output.
Control; Independently
Should pressure _____ significantly below 100 mm Hg, the ANS _____:
_____ the force of heart pumping.
_____ large venous reservoirs to get more blood to the heart.
_____ _____ most arterioles to allow blood to accumulate in arteries to increase arterial p
Fall; Responds; Increasing; Contracting; Generally constricting
What describes the physical behavior of blood as a fluid?
Hemodynamics examines the _____ between flow, pressure gradients, resistance, vessel cross-sectional area, and velocity.
Hemodynamic relationships _____ arterial pressure, cardiac output, and tissue blood flow (and explain the appearance of murmurs and bruits).
In Hemodynamics, what does F or Q represent?
Flow: Volume of blood moved with respect to time
In Hemodynamics, what does P represent?
Pressure: Force exerted by blood over a surface

(e.g., unit area of vessel wall)
In Hemodynamics, what does ΔP represent?
Pressure difference between two ends of the vessel

(P1 at origin, P2 at end)
In Hemodynamics, what does R represent?
Resistance: Impediment to flow in a vessel, expressed in resistance units
What does Ohm's law calculate?
Blood flow through a vessel
What is Ohm's law?
F = ΔP/R
Flow is proportional to ___ and inversely proportional to ___.
According to Ohm's law, what is the primary factor that alters the rate of flow?
Vascular resistance
What is blood flow? How is it expressed?
The amount of blood moved in a given time; ml / min or L / min
In adults the overall flow in the circulatory system is ___/___ which is the _____ _____.
5 L / min; Cardiac output (CO)
Blood flows in _____, or concentric circles, and is fastest at the _____. This flow is called _____ flow.
Streamlines; Center; Laminar
Laminar flow is _____, and due to the increasing speed of flow towards the _____ of the vessel, a ‘_____ profile for velocity of blood’ is created.
Silent; Center; Parabolic
Causes of turbulent blood flow :
_____ velocities
_____ _____ in the circulation
Passes over _____ _____ in vessels
Passes by an _____ or _____ _____
High; Sharp turns; Rough surfaces; Obstruction; Rapid narrowing
_____ currents or _____ are created resulting in greater resistance and friction in flow.
Eddy; Whorls
What 2 problems may turbulent blood flow result in?
Murmurs, Bruits
What are 2 disorders caused by the negative effects of wall stress on vessels?
Aortic aneurysm; Atherosclerosis
Resistance is the _____ to flow and is measured indirectly by dividing the _____ _____ _____ by the ____ _____.
Impediment; Vessel pressure difference (P1 – P2); Blood flow
The higher the _____, the lower the blood flow.
Blood flow will take the path of _____ _____.
Least resistance
In identical vessels, flow in _____ flow out.
With constriction, resistance _____ and flow _____. Diverted blood is divided among _____ resistance vessels.
Increases; Decreases; Lower
What is conductance?
Measure of blood flow through a vessel for a given pressure difference.
What is a measure of blood flow through a vessel for a given pressure difference termed?
Conductance is the _____ of resistance.

(C = 1 / R)
Changes in vessel _____ cause tremendous changes in the vessel’s ability to conduct blood.
Conductance of a vessel increases in proportion to the _____ power of the diameter
The relationship between vessel radius, vessel length and viscosity of the blood is described by _____ Law.

(F = πΔPr^4 / 8ηl)
The relationship between vessel _____, vessel _____ and _____ of the blood is described by Poiseuille’s Law.
Radius (r), Length (l), Viscosity (η)
_____ to _____ by the vessel increases with length of the vessel
Resistance to flow
Resistance increases as viscosity of fluid _____.
Resistance decreases as radius _____.
_____ _____ _____ contribute to blood viscosity as they exert frictional drag against the vessel wall.
Red blood cells
What is the hematocrit?
Cellular component of blood
Hematocrit of 40 means 40% of blood volume are _____, the rest is _____
Cells; Plasma
Average hematocrit values:
men = ___, women = ___
42; 38
what is an abnormally low hematocrit termed?
what is an abnormally high hematocrit termed?
What are bruits?
Abnormal blowing or swishing sounds
Hematocrit is _____ to viscosity.
All blood vessels are _____; as pressures increases the vessel stretches (dilates).
What type of blood vessels are distensible?
All types
Anatomically, _____ walls are stronger than _____.
Arterial; Veins
Veins are ___x more distensible than arteries.
What is defined as the total quantity of blood that can be stored in a given portion of the circulation for each mm Hg.
Vascular Compliance or Capacitance
What is a more meaningful parameter to measure than distensibility?
Vascular Compliance or Capacitance
Vascular Compliance or Capacitance is defined as the total _____ of blood that can be _____ in a given portion of the circulation for each ___ ___.
Quantity; Stored; mm Hg
Vascular _____ = Increase in volume / Increase in pressure
Vascular Compliance or Capacitance
Why may a highly distensible vessel not have high compliance?
The blood volume in the vessel must be accounted for
_____ = Distensibility x Volume
Vascular Compliance or Capacitance
_____ of a systemic vein is 24x that of arteries; it is 8x as _____ and has 3x the _____ (24 = 8 x 3).
Compliance; Distensible; Volume
_____-_____ relationships reflect compliance of the vascular system .
Arteries have _____ compliance so _____ _____ changes cause large pressure changes.
Low; Small volume
Veins have _____ compliance, so _____ _____ changes cause only small changes in pressure.
High; Large volume
When veins _____, more blood flows to the heart increasing _____ _____.
Constrict; Cardiac output (CO)
With each beat, _____ waves are sent through the arterial tree.
What almost equals [CO x R (of arterioles)]?
Mean arterial pressure (MAP)
What is the measure of the strength of the pressure wave?
Pulse pressure
What is defined as (systolic pressure – diastolic pressure)?
Pulse pressure
For an average person:
120 mmHg – 80 mm Hg = 40 mmHg (_____ _____ at aorta)
Pulse pressure
Increases in _____ _____ increase pulse pressure; conversely decreases in _____ _____ decrease pulse pressure.
Stroke volume; Stroke volume
Increases in stroke volume _____ pulse pressure; conversely decreases in stroke volume _____ pulse pressure
Increase; Decrease
Decreases in _____ _____ will increase pulse pressure; conversely increases in _____ _____ decrease pulse pressure.
Arterial compliance (or capacitance); Arterial compliance (or capacitance)
Decreases in compliance will _____ pulse pressure; conversely increases in compliance _____ pulse pressure
Increase; Decrease
What is the term that describes the effect where intensity of pulsations becomes progressively less in smaller arteries?
Damping describes how the intensity of pulsations becomes progressively _____ in _____ arteries
Less; Smaller
The degree of damping is proportional to the _____ and _____ of the vessels.
Resistance; Compliance
How do clinicians measure systolic and diastolic pressures indirectly?
Via the auscultatory method
Cuff inflation beyond ___ mm Hg occludes the brachial artery.
As cuff pressure is released, turbulence is generated when blood from the _____ side of the cuff meets the _____ blood .
Heart; Downstream
As cuff pressure is released, an audible event called _____ _____ occurs due to the turbulence of blood flow.
Korotkoff sounds
In general, blood pressure _____ with age.
What percentage of blood is in veins?
What can constrict and enlarge thereby storing small or large volumes of blood available when required by the circulation?

(Reservoir function)
Veins can constrict and enlarge thereby _____ small or large _____ of blood available when required by the circulation.
Storing; Volumes
Peripheral veins use the _____ ______ (_____ muscle contraction) mechanism to propel blood to heart and assist in _____ CO.
Venous pump; Skeletal; Regulating
_____, _____, _____ _____ veins and the venous _____ also serve as reservoirs.
Spleen; Liver; Large abdominal; Plexus
_____ flow goes into right atrium, so pressure in the right atrium is called the _____ _____ pressure.
Venous; Central venous
_____ _____ _____ is regulated by the balance between:
1. Ability of heart to pump blood out of the right atrium and ventricle into the lungs
2. Blood flows from the peripheral veins into the right atrium
Right atrial pressure (RAP)
If the right side of the heart is pumping strongly, Right atrial pressure (RAP) _____.
Factors that elevate Right atrial pressure (RAP):
_____ heart function
Any effect causing rapid inflow of blood into _____
_____ blood volume
_____ systemic vessel tone resulting in _____ peripheral venous pressures
_____ of arterioles
Decreased; Atrium; Increased; Increased; Increased; Dilation
Compression factors result in _____ to flow in peripheral veins.
Increased _____ _____ _____ causes blood to backup in the venous system; increasing venous pressure.
Right atrial pressure (RAP)
Increased Right atrial pressure (RAP) causes blood to backup in the _____ _____; increasing _____ pressure.
Venous system; Venous
Abdominal pressure increases _____ pressure in the legs.
To assist venous flow, some veins have internal _____ _____ that ensure blood passing the valve cannot flow backward.
One-way valves

(e.g., lower extremity)
_____ _____ to the heart is aided by the venous pump and respiratory pump.
Venous return
_____ _____ contraction squeezes veins (e.g., in legs), compressing them and pushing blood toward heart.
Skeletal muscle
During periods of sitting or standing motionless, the venous _____ does not assist venous _____.
Pump; Return
_____ incompetence results in varicose veins.
What is a sphygmomanometer?
Device used to measure blood pressure
What is a normal measurement of right arterial pressure (RAP)?
Approximately 0 mm Hg
Valve incompetence results in varicose veins, which predisposes one to _____.
What are the five types of structures in the microcirculation?
Nutrient arteries, Arterioles, Metarterioles, Capillaries; Venules
In microcirculation, the nutrient artery enters _____ or _____.
Organ; Tissue
In microcirculation, the arterioles are highly _____.
In microcirculation, metarterioles are _____ arterioles with _____ _____ fibers encircling the tube _____.
Terminal; Smooth muscle; Intermittently
In microcirculation, capillaries originate from _____ and their entrances are encircled by the _____ _____.
Metarterioles; Precapillary sphincter
In microcirculation, venules are _____ than arterioles and the muscle in the walls is _____ than muscle in the walls of arterioles, yet they can still _____ considerably
Larger; Weaker; Contract
What have the thinnest walls of all blood vessels?
Capillaries are divided into what two categories?
Continuous, Fenestrated
_____ capillaries are found in muscle, connective tissues and neural tissue.
_____ capillaries are found in kidney and intestine.
What type of capillary has large pores in it that allow high volumes of fluid to pass between the plasma and interstitial fluid.
Fenestrated capillaries have large _____ in them that allow high volumes of fluid to pass between the _____ and _____ _____.
Pores; Plasma; Interstitial fluid
Continuous capillaries have _____ _____; thin, curving channels between cells.
Intercellular clefts
Intercellular clefts in _____ capillaries allow water, dissolved _____ and small _____ to pass through the wall.
Continuous; Solutes; Ions
_____ capillaries have pores that allow _____ through the cell
Fenestrated; Transcytosis
In _____ capillaries, transcytosis _____ can form _____ channels
Fenestrated; Vesicles; Vesicular
Blood flows _____ through capillaries.
What is the term that describes the intermittent contraction of metarterioles and precapillary sphincters.
The term vasomotion describes the intermittent _____ of _____ and _____ _____.
Contraction; Metarterioles; Precapillary sphincters
_____ _____ is the primary regulator of vasomotion.
Oxygen concentration
Increase in the _____ of _____ usage in tissue causes periods of capillary blood flow to occur more _____.
Rate; Oxygen; Often
Increase in the _____ of _____ usage in tissue causes the duration of each period of capillary blood flow to be _____.
Rate; Oxygen; Longer
In _____, dissolved solutes and gases move by _____, determined by concentration _____ between _____ and _____ fluid.
Capillaries; Diffusion; Gradients; Plasma; Interstitial

Lipid _____ substances diffuse directly through the cell membrane of the _____.
Soluble; Capillary

(e.g., O2, CO2)
Lipid _____ substances cross the cell membrane via intercellular _____.
Insoluable; Clefts

(e.g., H2O, Na, Cl, glucose)
the space between cells is the _____; substance in this space is the _____ _____.
Interstitium; Interstitial fluid
_____ _____ and _____ _____ are two major solid structures in the interstitium.
Collagen fibers; Proteoglycan filaments
Almost all interstitial fluid is in form of a _____.
Bulk flow refers to mass movement of fluid between _____ and _____ _____ as the result of _____ or _____ pressure gradients.
Blood; Interstitial fluid; Hydrostatic; Osmotic
If the direction of bulk flow is into the capillary, the fluid movement is called _____.
If the direction of flow is out of the capillary, the fluid movement is called _____.
Capillary filtration is caused by _____ pressure that forces fluid _____ _____ the capillary through _____ cell _____.
Hydrostatic; Out of; Leaky; Junctions
Most capillaries show a transition from net _____ at the arterial end to net _____ at the venous end.
Filtration; Absorption
Most capillaries show a transition from net filtration at the _____ end to net absorption at the _____ end.
Arterial; Venous
Exceptions to the rule of capillary filtration and absorption are found in the _____ (_____ entire length) and _____ (only _____).
Kidney; Filters; Intestine; Absorbs
What is the lateral pressure component of blood flow that pushes fluid out through the capillary pores?
Hydrostatic pressure
What is determined by the solute concentration differences between two compartments?
Osmotic pressure
The main difference in solutes between plasma and interstitial fluid are the _____ present in _____.
Proteins; Plasma
Hydrostatic Pressure is the _____ pressure component of blood flow that pushes fluid _____ through the capillary _____.
Lateral; Out; Pores
Osmotic Pressure is determined by the _____ _____ differences between two compartments.
Solute concentration
What is the osmotic pressure due to the presence of proteins in plasma known as?
Colloid osmotic pressure
Colloid osmotic pressure exists because of the presence of _____ in _____.
Proteins; Plasma
Colloid osmotic pressure is NOT the same as _____ osmotic pressure; it is a measure of the osmotic pressure created by _____.
Total; Proteins
Because of _____ osmotic pressure, the osmotic gradient favors H2O movement by osmosis from _____ _____ into _____.
Colloid; Interstitial fluid; Plasma
_____ _____ pressure decreases along the length of the capillary as energy is lost due to _____.
Capillary hydrostatic; Friction
The average value of capillary hydrostatic pressure at the _____ end is 32 mm Hg and 15 mm Hg at the _____ end.
Arterial; Venous
Water movement will always be directed _____ _____ the capillary, with pressure _____ from the arterial end to the venous end.
Out of; Decreasing
_____ fluid flow across the capillary is determined by the difference between the _____ _____ _____ _____ (Pcap) favoring filtration and the _____ _____ _____ (π) favoring absorption.
Net; Capillary hydrostatic pressure gradient; Colloid osmotic pressure
Continuous capillaries have _____ junctions.
_____ (Pout) = hydrostatic pressure gradient = (Pcap – PIF)
_____ (πin) = colloid osmotic pressure gradient = (πIF – πcap)
Net pressure = _____ ______ gradient + _____ _____ _____ gradient.
Hydrostatic pressure; Colloid osmotic pressure
Net pressure at the _____ end of the capillary is 7 mm Hg.
The hydrostatic pressure gradient (Pcap) is greater than the colloid osmotic pressure gradient (π) at the _____ end of a capillary, favoring _____.
Arterial; Filtration
Filtration is usually _____ than absorption, resulting in bulk flow of fluid out of the _____ into _____ _____.
Greater; Capillary; Interstitial space.
Unless fluid is returned to the _____, the blood will become a sludge of _____ and _____.
Plasma; Cells; Proteins
Restoring lost fluid from capillaries to circulation is one of the functions of the _____ _____.
Lymphatic system
Vessels of the lymphatic system interact with the _____ system, the _____ system and the _____ system.
Cardiovascular; Digestive; Immune
Functions of the lymph system:
Return _____ and _____ to the circulation
Pick up _____ from _____ intestine and transfer it to the circulatory system
Filter, capture and destroy _____ _____
Fluid; Proteins; Fat; Small; Foreign pathogens
The _____ system is designed for _____ movement of interstitial fluid from the tissues to the circulation.
Lymph; One-way
_____ _____ lie close to all blood capillaries except in the kidney and CNS.
Lymph capillaries
Large gaps in lymph capillaries allow _____, _____and _____ matter to come into the capillary via bulk flow.
Fluid; Proteins; Particulate
Fluid, proteins, and particulate matter make up the _____.
Lymph capillaries connect to larger vessels, and eventually empty into the _____ circulation just under the _____ where the _____ _____ veins join the _____ _____ veins.
Venous; Clavicles; Right subclavian; Internal jugular
At intervals along the way, vessels enter lymph _____ that contain immunologically active cells such as _____ and _____.
Nodes; Lymphocytes; Macrophages
If _____ move from plasma to interstitial fluid, the _____ _____ _____ opposing filtration decreases.
Proteins; Osmotic pressure gradient
With less opposition to _____ _____ _____, fluid moves into the interstitial space.
Capillary hydrostatic pressure
Local swelling in response to inflammation is an example of _____ caused by redistribution of _____ from plasma to interstitial fluid.
Edema; Proteins
What is a sign that normal capillary-lymph exchange is disrupted?
Edema arises from one of two causes:
1. Inadequate drainage of _____.
2. Capillary filtration that _____ _____ capillary absorption.
Lymph; Greatly exceeds
What occurs with obstruction of the lymph system, particularly at lymph nodes?
Inadequate drainage of lymph
Causes of inadequate drainage of lymph:
1. _____
2. _____
3. _____ tissue growth following radiation therapy
4. Surgical removal of _____
Parasites; Cancer; Fibrotic; Nodes
Factors disrupting balance between capillary filtration and absorption:
1. Increase in _____ _____ _____
2. Decrease in _____ _____ _____
3. Increase in interstitial _____
Capillary hydrostatic pressure; Plasma protein concentration; Proteins
Plasma protein concentrations may decrease as a result of severe _____ or _____ failure.
Malnutrition; Liver
The _____ is the main site for plasma protein synthesis.
Excessive leakage of _____ _____ ____ blood will decrease plasma colloid osmotic pressure and increase net capillary filtration.
Proteins; Out of
On occasion, changes between filtration and absorption _____ homeostasis.
If arterial blood pressure falls due to hemorrhage or severe dehydration, _____ _____ _____ also falls. This change _____ fluid absorption.
Capillary hydrostatic pressure; Increases
If pressure falls low enough, net _____ in capillaries occurs rather than net _____, maintaining blood volume.
Absorption; Filtration
Each tissue controls its own blood flow in proportion to its _____.
Each _____ controls its own blood flow in proportion to its needs.
Tissue needs:
Delivery of ___
Delivery of nutrients; _____, _____, and _____ _____.
Removal of ___, ___ and other metabolites
Transport of various _____ and other substances
O2; Glucose, Amino, and Fatty acids; CO2; H+; Hormones
Blood flow is closely related to the _____ _____ of tissues.
Metabolic rate
What percentage of cardiac output is used by the tissues of the body?
The _____ are the main site of variable resistance in the systemic circulation.
The _____ contribute more than 60% of the total resistance to flow in the system.
Resistance in the arterioles is variable because of the large amounts of _____ _____ in their walls.
Smooth muscle
When smooth muscle contracts and relaxes, the _____ of the arterioles changes.
Radius or Diameter
Arteriolar resistance is influenced by both _____ and _____ control mechanisms.
Reflex; Vocal
_____ _____ maintain mean arterial pressure (MAP) and govern blood distribution.
Sympathetic reflexes
_____ _____ matches flow to the metabolic needs of tissue.
Local control
_____ act directly on arterioles by altering autonomic reflex control.
Increases in tissue _____ lead to increases in blood flow.

(Acute control)
Decreases in _____ availability to tissues increases tissue blood flow.
Oxygen availability decreases:
1. At _____ altitudes
2. In _____
3. _____ _____ poisoning – Hb can’t transport oxygen
4. _____ poisoning – Tissues unable to use oxygen
High; Pneumonia; Carbon monoxide; Cyanide
What are the two basic theories about how local blood flow is regulated when the rate of tissue metabolism changes or the availability of oxygen changes?
Vasodilator Theory, Oxygen (Nutrient) Lack Theory
Vasodilator theory:
_____ rate of metabolism or _____ availability of O2 causes an increased rate of formation of vasodilator substances (_____) in the tissue cells.
Increased; Decreased; Paracrines
In vasodilator theory, _____ diffuse through to precapillary sphincters, metarterioles and arterioles to cause _____.
Paracrines; Dilation
Paracrines that act as local vasodilators:
1. _____
2. _____ _____ compounds
3. _____ byproducts such as CO2, H+, K+, Lactic Acid
Adenosine; Adenosine phosphate; Metabolic
According to vasodilator theory, _____ concentrations change with _____ activity in the cells.
Paracrine; Metabolic
In vasodilator theory, not all vasoactive paracrines reflect changes in _____.
Kinins and histamine are potent vasodilators involved with _____.
Serotonin, released by activated platelets, triggers _____ to slow blood loss.
In oxygen lack theory, oxygen (nutrients) is required for vascular (_____) _____ contraction.
Sphincter; Muscle
In oxygen lack theory, _____ of nutrients causes sphincter muscle to ‘relax’ and naturally _____.
Absence; Dilate
In oxygen lack theory, increased _____ would increase oxygen use and decrease its availability to the _____ _____, also causing local vasodilation.
Metabolism; Sphincter muscle
If _____ metabolism increases, tissue O2 levels decrease and CO2 levels increase.

(Acute control)
Low O2 and high CO2 _____ arterioles, increasing blood flow into the tissue and bringing in O2 to match _____ metabolic demand and remove CO2.
Dilate; Increased

(Acute control)
This process is called _____ _____; increased blood flow accompanies increased metabolic activity.
Active hyperemia

(Acute control)
In the process called active hyperemia; increased _____ _____ accompanies increased _____ activity.
Blood flow; Metabolic

(Acute control)
What process occurs if blood flow to tissue stops completely for a few seconds to minutes?
Reactive hyperemia.

(Acute control)
If blood flow to tissue stops completely for a few seconds to minutes, metabolically produced _____ (CO2, H+) accumulate in interstitial fluid.

(Acute control)
When flow resumes after being stopped, _____ concentration of paracrines immediately triggers significant _____.
Increased; Vasodilation

(Acute control)
When flow resumes after being stopped and flow washes away the _____ , the arteriole _____ gradually returns to normal.
Vasodilators; Radius or Diameter

(Acute control)
Any acute increase in arterial pressure causes an immediate rise in blood flow, but within _____ _____ flow normalizes though _____ _____ may stay elevated.
One minute; Arterial pressure

(Autoregulation of blood flow)
The return of flow towards normal is called _____ of blood flow.
What are the 2 theories of autoregulation?
Metabolic, Myogenic
In the Metabolic Theory of _____, when _____ _____ becomes too great, excess flow provides too much O2 and other nutrients to tissues.
Autoregulation; Arterial pressure
In the Metabolic Theory of _____, The excess O2 and nutrients cause vessels to _____ and the flow returns almost to normal despite the _____ pressure.
Autoregulation; Constrict; Increased
In the Myogenic Theory of _____, _____ stretch of smooth muscle causes it to _____ for a few seconds.
Autoregulation; Sudden; Contract
In the Myogenic Theory of _____, When fibers in the _____ stretch due to increased BP, the _____ contracts and flow decreases back toward normal.
Autoregulation; Arteriole; Arteriole
In the Myogenic Theory of _____, At low BP the degree of stretch is less so smooth muscle _____ and allows _____ flow.
Autoregulation; Relaxes; Increased
In the Myogenic Theory of _____, The myogenic response is _____ to vascular smooth muscle and occurs in the _____ of neural or hormonal influences.
Autoregulation; Inherent; Absence
In the Myogenic Theory of _____, The myogenic response is most pronounced in _____ , but is observed in _____, _____, _____ and _____ vessels.
Autoregulation; Arterioles; Arteries, venules, veins and lymphatic
What occurs over hours, days and weeks when long-term changes in tissues occur?
Long-term regulation of blood flow
In long-term regulation of blood flow:
1. Sustained increases in _____ _____ occur
2. Sustained _____ increases in tissue occur
Arterial pressure; Metabolic
In long-term regulation of blood flow, the _____ and _____ of vessels change.
Size; Number
In long-term regulation of blood flow, _____ is an important stimulus for regulating tissue vascularity.
What is angiogenesis?
Growth of new blood vessels
Angiogenesis occurs in response to angiogenic factors released from:
1. _____ tissue
2. _____ growing tissue
3. Tissues with high _____ _____
Ischemic; Rapidly; Metabolic rates
Angiogenic factors include:
1. _____ _____ growth factor (VEGF)
2. _____ growth factor
3. _____
Vascular endothelial; Fibroblast; Angiogenin
Substances secreted or absorbed into the body fluids such as hormones or ions exert _____ control of the circulation.
Some substances that exert humoral control of the circulation are _____ products that are transported via the circulation throughout the body.
Some substances that exert humoral control of the circulation are formed in _____and have local effects on circulation
What are these substances?
Norepinephrine and Epinephrine
Angiotensin II
Vasopressin (ADH)
What are these substances?
Nitric Oxide
Vasodilator agents
Vasodilator agents may be released when _____ is damaged.
What does all of these things?
Exit cord in all thoracic and L1, L2 spinal nerves
Enter the paravertebral chain ganglia
Goes to innervate the circulation via:
1. Specific sympathetic nerves to heart and viceral vasculature
2. Spinal nerves going to periph
Sympathetic vasomotor fibers
Sympathetic vasomotor fibers:
Exit cord in all _____ and L1, L2 spinal nerves
Enter the _____ _____ ganglia
Goes to innervate the circulation via:
1. Specific nerves to _____ and _____ vasculature
2. _____ nerves going to _____ vasculature
Thoracic; Paravertebral chain; Heart; Visceral; Spinal; Peripheral
Sympathetic stimulation _____ resistance and _____ flow in small arteries and arterioles.
Increases; Decreases
Sympathetic stimulation causes _____ to _____ volume, returning blood to the heart.
Veins; Decrease
What would cause all of these?
Marked increase in heart activity
Increasing the heart rate
Enhancing strength of pumping
Enhancing volume of pumping
Sympathetic stimulation of the heart
Sympathetic stimulation of the heart:
1. Marked _____ in heart activity
2. _____ the heart rate
3. Enhancing _____ of pumping
4. Enhancing _____ of pumping
Increase; Increasing; Strength; Volume
_____, carrying vasoconstrictor nerve fibers, innervate all vessels except _____, _____ sphincters and some _____.
Sympathetics; Capillaries; Precapillary; Metarterioles
Parasympathetics play a _____ role in regulation of circulation.
The most significant parasympathetic effect is the control of _____ _____ via parasympathetic nerve fibers in the _____ nerve going to the heart.
Heart rate; Vagus
Parasympathetic stimulation _____ heart rate and muscle contractility.
Parasympathetic stimulation decreases _____ _____ and _____ _____.
Heart rate; Muscle contractility
What is located bilaterally in the reticular area of the medulla and lower pons?
Vasomotor center (VMC)
The vasomotor center (VMC) sends ____ impulses via cord and peripheral nerves to all _____, _____ and _____.
Sympathetic; Arteries; Arterioles; Veins
The vasomotor center (VMC) sends _____ impulses via the vagus nerve to the _____.
Parasympathetic; Heart
What is composed of these:
Vasoconstrictor area
Vasodilator area
Sensory area
Vasomotor center (VMC)
The vasomotor center (VMC) _____ area has neurons that become preganglionic fibers in the cord.
The vasomotor center (VMC) _____ area neurons project up to the vasoconstrictor area.
The vasomotor center (VMC) _____ area receives sensory input from CN X and IX: output goes to the other 2 areas (‘reflex’ loop, ex. baroreceptor)
The VMC vasoconstrictor area transmits signals continuously to sympathetic nerve fibers, this is _____ _____ _____.
Sympathetic vasoconstrictor tone
The VMC vasoconstrictor area transmits impulses that maintain a partial state of contraction in blood vessels is called _____ _____.
Vasomotor tone
_____ _____ of the VMC control heart activity by increasing heart rate and contractility.
Lateral portions
_____ _____ of the VMC signal the _____ _____ nucleus of the vagus, which then transmits parasympathetic impulses through the vagus to the heart to decrease heart rate and contractility.
Medial portions; Dorsal motor
The vasomotor center (VMC) can either increase or decrease _____ _____.
Heart activity
Heart rate and strength of contraction ordinarily increase with _____ and decrease with _____.
Vasoconstriction; Vasodilation
Reticular area:
Lateral and superior areas _____ the VMC
Medial and inferior areas _____ the VMC
Excite; Inhibit
What do these have in common?
Motor cortex
Anterior Temporal lobe
Frontal Orbital area
Anterior Cingulate Gyrus
These higher brain centers influence the vasomotor center (VMC)
Vasoconstrictor nerves use _____ neurotransmitter that acts on _____ receptors
Norepinephrine; α adrenergic
The adrenal medulla secretes _____ and _____ into circulation and acts on α and β _____ receptors systemically to cause constriction (α) or dilation (β).
Epinepherine; Norepinephrine; Adrenergic
The nervous system can increase arterial pressure within seconds by:
1. _____ almost all arterioles of the body which increases total peripheral resistance
2. _____ large vessels of the circulation thereby increasing venous return and CO
3. Directly incr
Constricting; Constricting; Heart rate; Contractility
Rapid increases in arterial pressure can occur during _____ or with extreme _____.
Exercise; Fright
Spray type nerve endings of baroreceptors are located in the walls of the _____ _____ and _____ _____.
Carotid sinus; Aortic arch
Baroreflex signals from the _____ _____ are transmitted by the Hering’s nerve to CN IX and then to _____ _____ and _____ of the medulla.
Carotid sinus; Solitary tract; Nucleus (NTS)
Baroreflex signals from the _____ _____ are transmitted through CN X into the _____ _____ and _____ of the medulla.
Aortic arch; Solitary tract; Nucleus (NTS)
_____ _____ receptors respond to pressures between ___ and ___ mmHg
Carotid sinus; 60; 80
Baroreceptor reflex is most sensitive at a pressure of ___ mmHg.
After baroreflex signals reach the solitary tract, secondary signals:
1. _____ the vasoconstrictor center
2. _____ the vagal parasympathetic center
Inhibit; Excite
Net effects of secondary baroreflex signals:
1. _____ of the veins and arterioles systemically
2. _____ heart rate and strength of contraction
Vasodilation; Decreased
Excitation of baroreceptors by high arterial pressure reflexively causes the arterial pressure to _____.

(Decrease in peripheral resistance and CO)
The _____ _____ functions when you change position from lying to sitting to standing.
Baroreceptor reflex
What is the condition where, upon standing, gravity causes blood to pool in lower extremities causing arterial pressure to decrease.
Orthostatic hypotension
The baroreceptor reflex causes carotid and aortic receptors to _____ their firing rate causing an _____ in sympathetic activity.
Decrease; Increase

(Increases in HR, force of contraction, peripheral resistance and CO )
Orthostatic hypotension has minimal importance in _____ _____ control of arterial pressure.
Long term
_____ change in pressure causes _____ to reset in 1 to 2 days to the new pressure to which they are exposed.
Chronic; Baroreceptors
Interaction with other systems, specifically the _____ - _____ ______ - pressure control system, assists the baroreceptors in maintaining normal arterial pressure.
Renal; Body fluid
What are the chemosensitive cells that are sensitive to decreased O2 or increased CO2 and H+ levels?
_____ receptors are located in the carotid bodies near the bifurcation and on the aortic arch.
Activation of chemosensitive receptors results in excitation of the _____ _____.
Vasomotor center (VMC)
Chemosensitive receptors are not stimulated until pressure falls below ___ mmHg.
_____ receptors found in _____ and _____ arteries minimize arterial pressure changes in response to changes in blood volume.
Low-pressure; Atria; Pulmonary
Increases in blood volume activate _____ receptors which then lower arterial pressure.
Low-pressure receptors send sympathetics to the _____ and other centers:
Low-pressure receptors sympathetic effects:
1. Hypothalamus _____ ADH secretion
2. _____ glomerular filtration rate
3. _____ water and sodium loss in urine
Decreases; Increase; Increases
What is the reflex by which an increase in atrial pressure also causes an increase in heart rate?
Bainbridge reflex
The Bainbridge reflex:
1. Stretch of _____ sends signals to _____ _____ via vagal afferents.
2. _____ _____ efferent signals via vagus and sympathetics to _____ heart rate and contractility
3. Prevents _____ of blood in veins, atria and the pulmonary circ
Atria; Vasomotor center (VMC); Vasomotor center (VMC); Increase; Damming
What is the response where CO2 buildup stimulates the sympathetic VMC area, causing an increase in systemic arterial pressure?
Central nervous system (CNS) ischemic response
In the CNS ischemic response, _____ buildup stimulates the _____ VMC area, causing an _____ in systemic arterial pressure.
CO2; Sympathetic; Increase
Arterial pressure elevation in response to cerebral ischemia is the _____ _____ _____.
CNS ischemic response
Degree of sympathetic _____ due to the _____ _____ _____ can be so great that some peripheral vessels become totally or almost totally occluded.
Vasoconstriction; CNS ischemic response

(e.g., kidney ceases production of urine)
What is one of the most powerful of all activators of the sympathetic vasoconstrictor system?
Central nervous system (CNS) ischemic response
The CNS ischemic response does not become significant until arterial pressure falls below ___ mmHg; greatest activation is at ___-___ mmHg
60; 15-20

(“last ditch stand”)
What is the special ischemic response due to increased cerebrospinal fluid (CSF) pressure?
Cushing reaction
The Cushing reaction:
1. _____ pressure rises to AP, compresses brain and arteries initiating _____.
2. _____ response causes AP to rise to higher level than _____
3. Helps to protect the vital centers of the brain from _____ and _____ loss
CSF; Ischemia; Ischemic; CSF; O2; Nutrient
Heart rate x Stroke volume = _____ _____
Cardiac output (CO)
What do these factors affect?
Basic level of body metabolism
Activity level (exercise)
Person’s age
Body size
Cardiac output (CO)
Average cardiac output:
1. _____ _____ = 5 L/min
2. _____ _____ _____ = 5.6 L/min
3. _____ = 4.9 L/min
Resting adult; Young healthy male; Women
Average cardiac output:
1. _____ _____ = 5 L/min
2. _____ _____ _____ = 5.6 L/min
3. _____ = 4.9 L/min
Male/Female/State involved
What is the term that describes the various factors of the peripheral circulation affecting flow of blood into the heart from veins?
Venous return
What is the primary controller of cardiac output?
Venous return
The Frank-Starling Law states that the
heart pumps what flows into _____ _____.
Right atrium
Increased blood flow into the right atrium _____ muscle and the heart _____ with increased _____.
Stretches; Contracts; Force
Under most _____ _____ conditions, cardiac output is controlled almost entirely by peripheral factors that determine venous return.
Normal unstressful
(sinus node rate + ANS input) x (venous return + force of contraction) = _____ _____
Cardiac output
What is determined by the sum of all various factors that control local blood flow systemically?
Cardiac output
All local blood flows summate to form the _____ _____.
Venous return
Stroke volume increases as _____ volume increases.

(Frank-Starling law)
What is end-diastolic volume determined by?
Venous return

(Frank-Starling law)
What do these factors affect?
1. Contraction / compression of veins returning blood to heart (skeletal muscle pump)
2. Pressure changes in the abdomen and thorax during breathing (respiratory pump)
3. Sympathetic innervation to veins
Venous return
Factors affecting venous return:
1. Contraction / compression of _____ returning blood to heart (skeletal muscle pump)
2. _____ changes in the abdomen and thorax during breathing (respiratory pump)
3. _____ innervation to veins
Veins; Pressure; Sympathetic
Under most normal conditions, long-term CO level varies _____ with changes in total peripheral resistance (TPR).

(TPR increases, CO decreases and vice versa)
There are limits to how much blood the heart can pump, which can be expressed quantitatively in the _____ _____ curves.
Cardiac output
In the normal heart, the plateau of ___ L/min is ___x the normal CO of 5 L/min.
13; 2.5
The heart can pump an amount of venous return up to ~ ___x before the heart becomes a _____ factor in control of CO.
2.5; Limiting
What do these factors cause?
1. Nervous stimulation of the heart
2. Hypertrophication of the heart muscle
The heart becoming a better (stronger) pump.
_____ stimulation and _____ inhibition increases pumping effectiveness by:
1. Increasing the HR
2. Increasing strength of heart contraction (“contractility”)
Sympathetic; Parasympathetic
Combining sympathetic and parasympathetic effects can raise the _____ level of the CO curve to almost _____ that of normal.
Plateau; Twice
A long-term increased workload, but not excessive, causes an increase in muscle mass and contractile strength. This is called _____.

(e.g., from marathon running)
The total effect of combining _____ _____ of the heart and _____, allows the heart to pump about 2.5x normal.
Nervous excitation; Hypertrophy
What effect do these have?
Coronary artery blockage (MI, heart attack)
Inhibition of nervous excitation of the heart
Pathological factors causing abnormal rhythm or rate
Valvular heart disease
Increased arterial pressure ; Hypertension
Congenital heart di
Decreased ability of the heart to pump blood
What do these factors affect?
1. Right atrial pressure that exerts backward pressure force on veins impeding flow into the right atrium
2. Degree of filling of the systemic circulation which forces blood toward heart (mean systemic filling pressure)
3. Re
Venous return

(Principle factors)
Factors affecting venous return:
1. Right atrial pressure that exerts _____ pressure force on veins impeding flow into the right atrium
2. Degree of filling of the _____ circulation which forces blood toward heart (mean _____ filling pressure)
3. _____ to
Backward; Systemic; Systemic; Resistance
The venous return curve relates venous return to the _____ _____ pressure.
Right atrial
_____ _____ into the heart is affected by right atrial pressure.
Venous return
When heart pumping capability is _____, the right atrial pressure rises and the _____ force of this rising pressure decreases venous return.
Diminished or Decreased; Backward
_____ _____ would be zero when the right atrial pressure rises to _____ the mean systemic filling pressure.
Venous return; Equal
At the same time the right atrial pressure is _____ causing venous stasis, pumping by the heart also approaches zero because of _____ venous return.
Rising or Increasing; Decreasing
Both arterial and venous pressures come to _____ when all flow in the systemic circulation ceases.

(mean systemic filling pressure = 7 mmHg)
When right atrial pressure falls below ___ mm Hg further increase in venous return ceases.

(atmospheric pressure)
_____ in the curve is caused by the _____ of the large veins entering the chest, preventing additional flow from peripheral veins.
Plateau; Collapse
Most resistance to _____ _____ occurs in the veins, though some occurs in the arterioles and small arteries as well.
Venous return
When resistance in veins _____, blood begins to be dammed up, mainly in the veins themselves.
As veins are highly _____ the rise in venous pressure is small, and _____ effective in overcoming resistance, and flow into the atrium _____ drastically.
Distensible; Not; Decreases
When _____ increase in arteries and arterioles, blood accumulates, but the _____ is much smaller than that of the veins.
Resistances; Capacitance
A slight accumulation of blood in arteries _____ the pressure greatly, and this pressure change does overcome much of the increased _____.
Raises or Increases; Resistance
Decrease in _____ to ½ normal allows 2x as much flow
_____ in resistance to 2x normal decreases flow to half that of normal
When right atrial pressure equals mean systemic filling (Psf) pressure, flow is _____.
Sympathetic stimulation makes the heart a _____ pump.
In the systemic circulation, what increases the mean systemic filling pressure because of contraction of the peripheral vessels and increases the resistance to venous return?
Sympathetic stimulation
In the systemic circulation sympathetic stimulation _____ the mean systemic filling pressure because of contraction of the peripheral vessels and it _____ the resistance to venous return
Increases; Increases
Increased _____ _____ increases CO and venous return curves. This can be maintained for _____ periods of time until other compensatory effects occur in seconds to minutes.
Sympathetic stimulation; Short
With _____ blood flow can increase from 3 - 4 ml/min to 50 to 80 ml/min in skeletal muscle.
Metabolic demand _____ flow.
Contracting muscle _____ flow transiently by compressing vessels.
With continued activity, other metabolic byproducts (paracrines) maintain increased _____ and _____ flow.
Vasodilation; Capillary
Decreased O2 concentration in muscle due to activity results in local _____.
What are these?
K+ ions
Lactic Acid
Metabolic byproducts (paracrines)
ANS-controlled redistribution of blood flow results from a combination of _____ in skeletal muscle arterioles and _____ in other tissues.
Vasodilation; Vasoconstriction
Paracrines cause local _____ that overrides the sympathetic signal for _____, resulting in shunting of blood flow from _____ to _____ tissues.
Vasodilation; Vasoconstriction; Inactive; Active

What are these effects?
1. Mass discharge of sympathetic nervous system through body with consequent stimulatory effects on entire circulation
2. Increase in arterial pressure
3. Increase in cardiac output
Effects of exercise on the circulatory system
Effects of exercise:
1. Mass discharge of _____ nervous system through body with consequent stimulatory effects on entire circulation
2. _____ in arterial pressure
3. _____ in cardiac output
Sympathetic; Increase; Increase
With onset of _____ there are multiple inputs to activate the vasomotor control center in the medulla resulting in _____ discharge.
Exercise; Sympathetic (norepinephrine)
What causes these effects?
1. Heart rate and pumping strength increase
2. Peripheral arterioles contract except those in active muscle, which are dilated
3. Veins are contracted which increases the mean systemic filling pressure, increasing venous return
Sympathetic discharge
Sympathetic discharge effects:
1. Heart rate and pumping strength _____
2. Peripheral arterioles _____, except those in active muscle, which are _____
3. Veins are contracted which _____ the mean systemic filling pressure, _____ venous return and CO
Increase; Contract; Dilated; Increases ; Increasing
Depending on the type of exercise, the arterial pressure can rise as little as ___ mmHg or as high as ___ mmHg.
20; 80
Whole body exercise shows _____ increase in CO because extreme _____ occurs simultaneously in large muscle groups.
Small; Vasodilation
_____ _____ is enhanced by skeletal muscle contraction and inspiration (respiratory pump).
Venous return
_____ of ventricles is prevented by increasing the heart rate; giving the heart less time to fill and decreasing likelihood of fiber damage.
During _____, parasympathetic activity at the sinus node is decreased and sympathetic output from cardiovascular control center esclates.
During _____, sympathetic input increases contractility and HR, increasing cardiac output.
What rises because of these?
1. Increased mean systemic filling pressure
2. Decreased resistance to venous return in active tissues
Venous return curve
Venous return curve rises during:
1. _____ mean systemic filling pressure
2. _____ resistance to venous return in active tissues
Increased; Decreased
Normal _____ blood flow at rest averages 225 ml/min or 4-5% or total cardiac output.
_____ exercise increases CO, pumps against higher arterial pressure, and _____ blood flow increases _____- to _____fold to supply increased energy needs of the cardiac muscle.
Strenuous; Coronary; Three; Four
Because the heart contracts during strenuous exercise, blood flow during systole _____ and during diastole blood flows rapidly in the _____ vessels.
Decreases; Coronary
Local flow is regulated by local arteriolar _____ in response to metabolic demands (primarily O2) of the cardiac tissue.
Decreased heart activity is accompanied by decreased _____ blood flow.
____ stimulation slows heart, decreases contractility and rate of metabolism. The result is indirect constriction of _____ arteries.
Vagus; Coronary

_____ stimulation of _____ vessels increases HR, contractility and rate of metabolism. The result is indirect dilation of _____ vessels.
Sympathetic; Coronary; Coronary

How does the ANS directly affect vasculature?
_____ stimulation (vagus, (ACh) has a direct effect to dilate the coronary arteries.

_____ stimulation (epi- or norepinephrine) can vasoconstrict or vasodilate depending on the receptor activated. α receptors ____; β receptors ____
Sympathetic; Constrict; Dilate

_____ factors – especially myocardial _____ consumption – are the major controllers of myocardial blood flow.
Metabolic; O2
Whenever the direct ANS effects alter _____ blood flow in “the wrong direction”, the _____ control of _____ flow usually overrides the direct ANS effects within seconds.
Coronary; Metabolic; Coronary
Respiratory system processes:
1. Pulmonary _____
2. _____ of O2 and CO2 between alveoli and blood
3. _____ of O2 and CO2 in the blood and body fluid
4. _____ of Ventilation
Ventilation; Diffusion; Transport; Regulation
Calculation of lung zone 2 flow:
_____: 25-15 = 10 > 0
_____: 8-15 = -7 < 0
Systole; Diastole
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