3-1: Errors 1

Front 1

Blood flow through heart beginning with VC.

Compare pressures on each side of heart.

Back 1

VC==>RA-->RV-->PA-->PV-->LA--LV

P in R side of heart is low (2 mmHg)
P in L side of heart is highest in LV (LA is pretty low)

LV: 120/5
Ao: 120/80

Front 2

What events define the two heart sounds?

Back 2

Lub = mitral valve close
Dub = aortic and pulmonic valve close

Front 3

What is the primary pumping chamber of the heart?

Back 3

LV

Front 4

Which organ extracts the most oxygen?

Back 4

Brain

Front 5

Artery or Vein:
Contains alpha-1 and beta-2 receptors

Back 5

Artery

Front 6

Cardiac Output = ?

Back 6

Cardiac Output = Stroke Volume (cc's per beat out of ventricle) x Heart Rate

Front 7

Artery or Vein:
Innervated by symphathetic nervous system

Back 7

Vein

Front 8

Blood Pressure = ?

Back 8

Cardiac Output x Systemic Vascular Resistance (presented by aa of body)

Front 9

How is the perfusion of capillaries controlled? What branch of the nervous system is responsible for this?

Back 9

Dilation/Constriction of arterioles and pre-capillary sphincters

Regulated by symphathetic innervation of BVs and vasoactive metabolites

Front 10

If runner has increased blood flow during exercise, what is the effect on blood pressure?

Back 10

Although BP = Q x systemic vasc resist, BP stays the same, but systemic vascular resistance decreases--runners need to cool down so BP doesn't drop?

Front 11

What are the components of diastole?

Back 11

Isovolumic relaxation
Rapid Ventricular Filling (increase in volume)
Atrial Contraction (kick)

Front 12

Which blood vessel types exhibit the largest area?

Back 12

Capillaries, then veins, then arteries

Front 13

Describe volumic changes during LV filling during the cardiac cycle.

Back 13

Systole: volume drops and stops

Diastole: rapid filling, nothing happens, and then more filling (atrial kick)

Front 14

Which blood vessel types receive the greatest blood volume?

Back 14

Veins, then arteries, then capillaries

Front 15

Systole begins with closure of the ___________

Back 15

mitral valve

Front 16

What is velocity? Equation?

Back 16

Velocity = rate of displacement of blood per unit time

v = Q/A
where v = velocity
Q = flow
A = cross-sectional area

Front 17

Diastole begins with closure of the ____________

Back 17

aortic valve

Front 18

What is the relationship between area and velocity?

Back 18

Incerse relationship (v=Q/A), so
Small area-->High velocity

Front 19

What are the stages of systole?

Back 19

Isovolumic contraction (mitral and aortic valves closed), when LV Pressure exceeds aortic Pressure, aortic valve opens

[S1: closure of mitral and aortic valves]

Front 20

Where is the velocity of blood flow highest?

Back 20

v=Q/A
Thus in the vessels with the smallest area, which are:
Aorta, then vena cava, then arteries

Front 21

S1 vs S2 events

Back 21

S1: mitral and tricupsid closure
S2: aortic and pulmonic closure

Front 22

Where is the velocity of blood flow the lowest? Why would this be advantageous?

Back 22

Capillary bed (largest area)--allows for more time for exchange of nutrients

Front 23

How does splitting of the second heart sound occur?

Back 23

Aortic valve closes before pulmonic closure and these events differ even more in time upon inhalation

Front 24

What is the equation for calculating changes in pressure?

Back 24

deltaP=Q x R
Where
Q = flow (mL/min)
R = Resistance (mmHg/mL/min)

Front 25

Events of systole vs events of diastole

Back 25

Systole:
Systole begins when mitral valve closes (triscupid valve closes too)
Pressure builds with ISOVOLUMIC CONTRACTION
Pressure opens pulmonic and aortic valves
Ejection

Diastole:
Begins when aortic and pulmonic valves close
As ventricles relax, pressure falls via ISOVOLUMIC RELAXATION
When pressure low enough, mitral and tricuspid valves open
Results in PASSIVE VENTRICULAR FILLING
Followed by ATRIAL KICK

Front 26

What is the equation for calculating resistance?

Back 26

R=deltaP/Q

Front 27

Compliance vs Stiffness

Back 27

Compliance: proportional to deltaV/deltaP (more compliant less of a change in P with a change in V; a good thing)

Stiffness: deltaP/deltaV

Front 28

What is Total Peripheral Resistance?

Back 28

Resistance of entire systemic vasculature

AKA Systemic Vascular Resistance

Front 29

Calculate the vascular resistance of the left kidney given:

Blood flow to the left kidney is measured at 500 mL/min

Pressure in renal artery is 100 mmHg

Pressure in the renal vein is 10 mmHg

Back 29

R = deltaP/Q

R = (100-10)/500 = 0.18 mmHg

Front 30

In a filling curve (P vs V), how would you identify a non-compliant LV?

Back 30

Higher change in Pressure for any given Volume (up and to the left)

Front 31

What are causes of diastolic dysfunction (stiffness)?

Back 31

LV Hypertrophy (chronic HTN, valvular heart dz, cardiomyopathy)

(anything causing LV to stretch or thicken)

Myocardial ischemia or infarction

Front 32

What pressure drop would one measure to calculate the systemic vascular resistance?

Back 32

Mean Arterial Pressure - Mean Right Atrial Pressure

Front 33

Preload vs Afterload

Back 33

Preload = Wall tension during diastole (ventricular filling)

Afterload = Wall tension during systole (ventricular ejection; EMPTYING)

Where wall tension = P x radius (of sphere)/2h

h=wall thickness

Front 34

What pressure drop would one measure to calculate the pulmonary vascular resistance?

Back 34

Mean Pulmonary ARTERIAL Pressure - Mean LEFT ATRIAL Pressure (can't get into pulmonary vein!)

Front 35

What is Poiseuille's equation for resistance?

Back 35

R = 8nl/pi*r^4

Where n = blood viscosity
l = length of blood vessel
r= vessel radius

Front 36

What is the most important determining factor of preload? Why?

Back 36

Pressure change during diastole is low, but volume change is huge so radius increases!

Wall tension = P x r/2h

Front 37

Resistance increases as viscosity ________.

Back 37

Increases

Front 38

What is the most important determining factor of afterload? Why?

Back 38

Systolic Pressure (BP)

As soon as mitral valve closes, pressure increases a lot

Front 39

How can you increase preload? Decrease?

Back 39

Inc: Give fluid

Dec: Diuretic

Front 40

Resistance increases as length ________.

Back 40

Increases

Front 41

How is afterload increased?
Decreased

Back 41

Any drug that increases, lowers BP

Front 42

Resistance increases as radius __________.

Back 42

Decreases TO THE FOURTH POWER

Front 43

Frank-Starling curves demonstrate what relationship?

Back 43

Preload on x-axis (LV End-Diastolic Pressure)
Cardiac output on y-axis

As increase preload, cardiac output increases, but eventually levels off

Front 44

Is resistance in the body considered in series or in parallel? What equation would you use to calculate this?

Back 44

Resistance is in parallel (blood doesn't flow through each organ in series):
Parallel Resistance:
Rtotal = 1/R1 + 1/R2 +1/R3 etc

(Series resistance would be calculated by adding all resistances)

Front 45

As you increase LVDP, you increase ________.

Back 45

Stroke volume (cardiac output)

Front 46

What is laminar flow? How is it interrupted?

Back 46

Laminar flow is a parabolic profile (flow is quickest in the middle) of velocity and is interrupted by irregularities in the vessel (causes turbulence)

Front 47

How would a heart failure Frank-Starling curve appear?

Back 47

Would have decreased stroke volume (cardiac output) for a given LV EDP, so upon administration of fluid (to inc volume and then radius) wouldn't get as much of an inc'd output

Front 48

What are the Reynold's numbers for laminar/turbulent flow?

Back 48

Reynold's < 2000 = Laminar Flow

Reynold's > 2000 = turbulent flow

Front 49

How is LA pressure measured?

Back 49

Catheterize pulmonary arteriole (Right side of heart) bc will measure Pressure of Pulmonary Vein which = LA pressure

Front 50

What is compliance in blood vessels proportional to?

Back 50

Compliance is proportional to deltaV/deltaP

Front 51

Arteries vs Veins:
Compliance

Back 51

Compliants in veins is high (can hold large volume of blood at low pressure because they expand)

Compliance of arteries is lower (hold a lower volume at a higher pressure)

Older arteries are least compliant

Front 52

What does the Fick Method measure?

Back 52

Measures cardiac output

Done with Waters Hood

Front 53

What is the Fick Principle?

Back 53

Higher cardiac output will result in higher venous oxygen saturation (less deoxygenated blood on return of RBCs to lungs)

Front 54

Where does the largest drop in mean pressure occur in the cardiovascular system?

Back 54

At arteriolar level

Front 55

_______ pressure is pulsatile due to the cardiac cycle.

Back 55

Arterial

Front 56

How is oxygen saturation of the pulmonary vein measured?

Back 56

Measure from any artery (only difference is oxygen taken by heart which is minimal)

Front 57

Diastolic vs Systolic:
Pressure

Back 57

Diastolic: lowest pressure
Systolic: highest pressure

Front 58

If the cardiac output is low, the mixed venous O2 content is __________ than normal.

Back 58

Lower than normal

Front 59

How is mean pressure calculated?

Back 59

Mean pressure = Diastolic pressure + 1/3*Pulse Pressure

Where Pulse Pressure = (systolic pressure - diastolic pressure)

Front 60

What happens to the Frank-Starling curve with a surge of epinephrine?

Back 60

Higher cardiac output, shift curve up and to left