Arterial Physiology (Lecture 2)

Question 1

Blood will move from an area of _____ energy to an area of _____ energy.

Answer 1

high (pressure)
low (pressure)

Question 2

What does the Bernoulli principle state?

Answer 2

When a fluid flows without change in velocity from one point to another, the total energy content remains constant, providing no frictional losses

Question 3

What is more viscous - fluid or honey?

Answer 3

Honey

Question 4

Velocity and flow are related by which equation?

Answer 4

V = Q/A

Question 5

The total area occupied by the capillaries is how much greater than the aorta?

Answer 5

600 times greater

Question 6

If blood flow remains constant, velocity ____ when the area decreases, and vice versa.

Answer 6

increases

Question 7

What is the equation for Poiseuille’s Law?

Answer 7

Q= π (P1−P2) r^4 / 8ηl

Question 8

What has the biggest impact on flow?

Answer 8

Radius

Question 9

What is the most important determinant of blood flow?

Answer 9

Radius

Question 10

A decrease in the radius of a vessel by half will increase the energy losses by a factor of… ?

Answer 10

16

Question 11

A doubling in the length of a vessel will yield an increase the energy losses by a factor of… ?

Answer 11

2

Question 12

What is the equation for Ohm Law?

Answer 12

R = △P / Q

Question 13

When you combine Poiseuille Law and Ohm law, what equation do you get?

Answer 13

R = 8ηl / π r^4

Question 14

For resistances in series (one vessel after another), what is the equation?

Answer 14

Rₜ = R1 + R2 + R3

Question 15

For resistances in parallel (vessels side by side), what is the equation?

Answer 15

1/Rₜ = 1/R1 + 1/R2 + 1/R3

Question 16

The more parallel elements in a network, how will this affect the resistance of the network?

Answer 16

Lower overall resistance

Question 17

A low resistance flow profile has what type of characteristic flow throughout the cardiac cycle?

Answer 17

Antegrade

Question 18

What type of flow does a high resistance flow profile display?

Answer 18

Both antegrade and retrograde

Question 19

How can some high resistance tissue beds be changed into low-resistance beds?

Answer 19

Exercise

Question 20

How can some low resistance tissue beds be changed into high-resistance beds?

Answer 20

Eating

Question 21

What is ‘Re’?

Answer 21

The Reynolds Number; directly proportional to the velocity of blood, density of blood, and radius of blood vessel.

Question 22

Flow will be laminar with an Re below what?

Answer 22

Re below 2000

Question 23

Flow will be turbulent with an Re above what?

Answer 23

Re above 2000

Question 24

What is Capacitance?

Answer 24

The ability of a vessel to store energy

Question 25

Stiffer walls of the heart indicate what for the pressure in both systole and diastole?

Answer 25

In systole, greater pressure In diastole, reduced pressure

Question 26

If interstitial O2 levels fall, which vessel dilates?

Answer 26

arterioles

Question 27

What is the difference between Fibrous plaque and Complicated plaque?

Answer 27

Fibrous - smooth, composed of smooth muscle and fibrous tissue and lacks calcs Complicated - irregular surface, loss of the normal endothelium and calcs present

Question 28

Where does Atherosclerosis typically develop?

Answer 28

Branch points and bifurcation

Question 29

A critical stenosis is defined at which percentage?

Answer 29

Cross sectional area reduced by 75%

Question 30

A stenosis in which area can become critical with a less severe degree of narrowing?

Answer 30

high flow/ low resistance