Functional Murmur

Question 1

What is the equation of Hemodynamics that describes flow?

*What is it after all substitutions are made?

Answer 1

Flow (Q) = Pressure Differential (P) / Resistance (R)
**Becomes Q = R^4
(24-26)

Question 2

True or False: People with anemia or polycythemia will have altered blood flow in their life? Why or why not?

Answer 2

True
Change in RBC’s will change viscosity of blood, which will effect blood flow
(25)

Question 3

What is the single greatest determinant of flow through a blood vessel?

Answer 3

Diameter

26

Question 4

How does blood flow through a blood vessel…in bulk downstream?

Answer 4

No, there is a parabolic velocity created by symmetrical streamlines of flow (due to drag against the vessel walls) and is called **Laminar Flow
(27)

Question 5

In Laminar Flow of blood, where is blood flowing the fastest?

Answer 5

Fastest in the center (slower on the edges)

27

Question 6

Turbulent flow happens when streamlines are disturbed; What is noise in a vessel referred to? What is noise in valves referred to?

Answer 6

Vessel noise = Bruit
Valve noise = Murmur
(27)

Question 7

What effect will stenosis have on velocity and flow of blood?

Answer 7

Velocity increases while flow decreases

27

Question 8

What is Reynolds Number?

What is the equation for Reynolds Number?

Answer 8

= the point where turbulence happens
Velocity/Viscosity
(27)

Question 9

What is the usual de-stabilizing factor for Reynolds Number?

Answer 9

Velocity

28

Question 10

What effect does turbulence have on shear forces?

Answer 10

Increases shear forces = damage to blood vessels causing clotting
(27)

Question 11

When intravascular pressure stretches blood vessels in proportion to their ability to absorb more blood, this is called?

Answer 11

Compliance (or distensibility)
= change in volume / change in pressure
(28)

Question 12

True or False: Arteries are very compliant and veins are not very compliant?

Answer 12

False: Arteries are NOT very compliant
Veins are very compliant
(29)

Question 13

What would happen to pressure in the venous and arterial system with a little increase in volume?

Answer 13

Venous system would not change much (=compliant) and Arterial system would dramatically increase in pressure (not very compliant)
(29)

Question 14

True or False: The arterial system vessels are known as capacitance vessels?

Answer 14

False. The arterial system is known as the resistance vessels
Venous system = capacitance vessels
(29)

Question 15

About how much blood is stored in the systemic veins? Systemic arteries?

Answer 15

2/3 in veins
15% in arteries
(29)

Question 16

Which statement is true:
A) Functional murmur is a normal condition of hemodynamics
B) Reynolds number is briefly exceeded in functional murmur due to cardiac vibrations OR turbulence in the aortic arch
C) Functional murmur is seen in about 80% or more of children

Answer 16

All are true

31