Arterial Physiology

Question 1

What is known as the flow through two points being directly proportional to the potential difference across two points, and inversely proportional to the resistance between them?

Answer 1

Ohm’s Law

Question 2

What is known as the measure of a blood vessel’s ability to increase the volume of blood it holds without a large increase in blood pressure?

Answer 2

Capacitance

Question 3

The total energy of a system is made up of?

Answer 3

Kinetic and potential energy

Question 4

What is the potential energy in the bodies arterial system?

Answer 4

Intravascular pressure

Question 5

What is the kinetic energy in the bodies arterial system?

Answer 5

Velocity of moving blood

Question 6

What is the pressure of the right atria in the heart?

Answer 6

2-6 mmHg

Question 7

What is the highest and lowest pressure chamber in the heart?

Answer 7

Highest = LV

Lowest =RA

Question 8

Is gravitational potential energy increased or decreased BELOW the reference point (RA of the heart)?

Answer 8

Decreases below the reference point

Question 9

What is known as the pressure within vessels related to the reference point? (RA)

Answer 9

Hydrostatic pressure

Question 10

Does hydrostatic pressure increase or decrease as you go lower in the body?

Answer 10

Increased due to the weight of the column of blood within the vessels

Question 11

The farther you go from the reference point does what to the hydrostatic pressure?

Answer 11

Increases

Question 12

What is the most important influence on blood viscosity?

Answer 12

Hematocrit

Question 13

Inertial energy loss is dependent on what factors?

Answer 13

1. Density of blood
2. Velocity of flow

Question 14

T or F? Energy losses because of viscosity effects are greater than those because of inertia?

Answer 14

TRUE

Question 15

Velocity and flow are related by what equation?

Answer 15

V = Q/A

Question 16

As diameter decreases, what happens to velocity?

Answer 16

Increases

Question 17

T or F?The cross-sectional area of the capillaries is greater than that of the Ao?

Answer 17

TRUE - 600x greater

Question 18

Equation for Ohm’s Law?

Answer 18

R = change in pressure / Q

Question 19

Equation for Resistance to flow?

Answer 19

R = (8 x viscosity x L) / (pi x r^4)

Question 20

Changes in vessel resistance are mostly all due to what factor?

Answer 20

Changing radius because it is calculate to the 4th power

Question 21

Resistance in series?

Answer 21

Sum of all resistances of each vessel

Question 22

Resistance in parallel?

Answer 22

Reciprocal of the total resistances of the system

Question 23

What happens to the resistance with more parallel elements in a network?

Answer 23

Resistance will decrease in the system

Question 24

What do low resistance arterial waveforms look like?

Answer 24

Antegrade forward flow (above the baseline)

Question 25

What do high resistance arterial waveforms look like?

Answer 25

Both antegrade forward flow (systole) and retrograde flow reversal (diastole)

Question 26

What is turbulent flow defined by?

Answer 26

Reynolds number (Re)

Question 27

Re is directly proportional to what factors?

Answer 27

Velocity Density Radius

Question 28

Re is indirectly proportional to what factor?

Answer 28

Viscosity

Question 29

Turbulence develops mainly due to what changing factors?

Answer 29

Velocity Radius

Question 30

What Re number will create turbulence?

Answer 30

>2000

Question 31

What is the term used for converting the pulsatile output of the heart to a steady flow through the capillaries via elastic conduits and high-resistance terminals?

Answer 31

Hydraulic filtering

Question 32

What refers to the ability of a vessel to store energy?

Answer 32

Capacitance

Question 33

What is the formula for capacitance?

Answer 33

change in V / change in P

Question 34

How do stiffer vessel walls affect pressure in systole and diastole?

Answer 34

Systole = greater pressure Diastole = reduced pressure

Question 35

What happens to vessel capacitance as we age?

Answer 35

Decreases - becomes more stiff

Question 36

When oxygen levels fall in the arterioles, what happens to the vessel?

Answer 36

Vasodilation to bring more blood flow to the area, increasing oxygen

Question 37

Fibrous plaque

Answer 37

1. smooth surface 2. composed of smooth muscle and fibrous tissue 3. lacks calcification

Question 38

Complicated plaque

Answer 38

1. Irregular surface 2. Loss of the normal endothelium 3. Calcification is present

Question 39

Where does atherosclerosis typically develop?

Answer 39

1. Branch points 2. Near bifurcations

Question 40

Where is most inertial energy loss in presence of stenosis?

Answer 40

When blood EXITS a stenosis into turbulent flow

Question 41

At what point is a stenosis considered 'critical'?

Answer 41

When the cross-sectional area of a vessel has diminished 75% or greater

Question 42

What can collateral arteries be separated into?

Answer 42

1. Stem arteries 2. Midzone collateral 3. Re-entry arteries