hemodynamics Flashcards

1
Q

pressure

A
  1. highest in aorta
  2. Pressure decreases through system, especially in resistance vessels (sm arteries & arterioles)
  3. low in capillaries and venous system
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

volume

A
  1. Total blood volume ~ 5 L

2. Largest volume in veins (“capacitance vessels”)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

flow equation

A

Q= ΔP/ R

Q: blood flow
P: pressure
R: resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

flow in must equal

A

flow out

the total flow is constant throughout the CV system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Flow (Q)

A

volume per unit time (ml/min)

CONSTANT through system (since closed loop)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

cardiac output (CO) =

A

(Pa - Pv) / TPR

Pa= mean arterial blood pressure
Pv= venous blood pressure
TPR = total peripheral resitance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

V (Velocity) =

A

Q/A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

velocity is highest in the

A

aorta (lowest total cross sectional area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

velocity is lowest in the

A

capillaries (greatest cross sectional area)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is the cardiac output?

A

the volume of blood pumped per minute by the heart

5L/min at rest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Cardiac output corresponds to the

A

total flow in the cardiovascular system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

poiseuelle’s Equation

A

Q = ΔP x (π r^4)/8nl

R is the radius
n is the viscosity
l is the length

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

if you increase radius?

A

decrease R and increase Q

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

if you increase viscosity?

A

increase R and thus decrease Q

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

if you increase length?

A

increase R and thus decrease Q

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is the biggest determinant of flow?

A

Radius because flow is proprotional to the 4th power of the radius

17
Q

Resistance in parallel

A

decreases the total resistance

18
Q

Rf of a parallel network is ____ than the resistance of a single vessel

19
Q

changing the R of a single vessel effect the system how?

A

little effect on the whole system

20
Q

the total resistance in the capillary beds is

A

low and independent of the individual capillaries because there are many parallel vessels.

21
Q

resistance in a series is

A

additive

Rf= R1 + R2 + R3 + …

22
Q

total resistance of a series is ___ than the resistance of any individual vessel

23
Q

blood flow through a series is

A

constant, but the pressure drops

24
Q

laminar flow

A
  1. most efficient
  2. velocity fastest in the center, zero at the edge
  3. flow equation assumes laminar flow. Not true in the CV system
25
turbulent flow
1. irregular with eddies and vortices 2. less efficient--requires more pressure to achieve same velocity 3
26
what promotes turbulent flow?
1. large diameter 2. high velocity 3. low viscosity 4. changes in diameter 5. irregularities on walls
27
turbulent flow produces
shearing forces that can damage vascular endothelium
28
Heartbeat produces:
pulsatile flow in aorta, but pulsatile flow requires more work. Pulse pressure is dampened in arterial system.
29
in the capillaries, flow is
continuous