Lecture 10 Arterial and Venous Systems and Lymphatics Flashcards

1
Q

What are some of the factors that increase lymph flow, and also interstitial fluid pressure?

A

Elevated capillary hydrostatic pressure

Decreased plasma colloid osmotic pressure

Increased interstitial fluid colloid osmotic pressure

Increased permeability of capillaries

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

How do you calculate the rate of lymph flow?

A

Rate of Lymph Flow =

interstitial fluid pressure x activity of lymphatic pump

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

True or False:

Lymph vessels posses 1-way valves similar to veins.

A

True

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

At what condition does lymph flow reach its maximum?

A

When interstitial pressure rises slightly above atmospheric pressure.

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

The least amount of damping of the pressure pulses would occur in which of the following components of the circulatory system?

a) femoral artery
b) arterioles
c) capillaries
d) venules

A

a) femoral artery

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

Which of the following factors affect pulse pressure?

a) vascular elastance
b) arterial compliance
c) stroke volume
d) all the above
e) B and C only

A

e) B and C only

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Which of the following is the most important means for the exchange of substances between the blood and the interstitial fluid?

a) blood hydrostatic pressure
b) capillary oncotic pressure
c) diffusion
d) interstitial fluid hydrostatic pressure
e) osmosis

A

c) diffusion

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

What is the definition of vascular distensibility?

A

Vascular distensibility -> (increase in volume) /(increase in pressure) X (original volume)

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

What affect does increasing the pressure in a vessel have on the vascular distensibility?

A

Increasing pressure would decrease vascular distensibility.

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

Does vascular distensibility increase or decrease when volume increases?

A

The vascular distensibility will increase.

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

True or False:

Pulmonary artery distensibility are about 6 times that of systemic arteries.

A

True

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

Fill in the Blank:

Pulmonary vein distensibilities are about the _________ as for systemic veins.

A

same

**Thus, pulmonary and systemic veins have about the same distensibility.

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

How much more distensible are veins than arteries?

A

8 times more distensible

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

What does capacitance describe?

A

Capacitance describes the distensibility of blood vessels.

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

The formula for vascular compliance = increase in volume / increase in pressure. What does vascular compliance tell us?

A

That the total quantity of blood (ml) that can be stored in a given portion of the circulation for each mmHg rise in pressure.

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

Fill in the Blank:

Capacitance (ml/mmHg) is __________ proportional to elastance.

A

Inversely

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is compliance equal to?

A

compliance is equal to distensibility X volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

True or False:

Capacitance is inversely proportional to volume and directly proportional to pressure.

A

FALSE - capacitance is directly proportional to volume and inversely proportional to pressure.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Fill in the Blank:

_________describes how volume changes in response to a change in pressure.

A

Capacitance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Is capacitance much greater for veins or arteries?

A

Capacitance is much greater in veins.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

True or False:

Capacitance of arteries decreases with age.

A

TRUE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the relationship between elastic tissue, elastance, and compliance?

A

The greater the amount of elastic tissue in a blood vessel, the higher the elastance and the lower the compliance.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What does compliance measure?

A

Compliance is a measure of the ease with which a hollow viscus may be distended.

*example: volume change resulting from the application of a unit pressure differential between the inside and outside of the viscus; the reciprocal of elastance.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What does vascular compliance tell you?

A

Total quantity of blood that can be stored in a given portion of the circulatory system.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is elastance a measure of?

A

The tendency of a hollow viscus to recoil toward its original dimensions upon removal of a distending or collapsing force.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

A systemic vein is about eight times as distensible as its corresponding artery and has a volume about three times as great. How would the systemic vein’s compliance compare to that of a corresponding artery?

A

Compliance = (8) x (3) = 24

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Study figure 15-1 from the book.

A

Guyton and Hall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

How do you calculate pulse pressure?

A

pulse pressure = stroke volume / arterial compliance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Given that pulse pressure = stroke volume / arterial compliance, comment on the factors that would negatively affect pulse pressure? Thus, what would increase pulse pressure and what is the most important determinant of pulse pressure?

A

Stroke Volume Output of the Heart:

  • most important determinant of pulse pressure
  • diastolic pressure remains unchanged during ventricular systole
  • pulse pressure increases to the same extent as the systolic pressure

Compliance of the Arterial Tree:
-Decreases in compliance (capacitance)
>e.g., aging, result in an increase in pulse pressure

30
Q

What are 2 of the 4 conditions that cause abnormal contours of the pressure pulse wave?

A

Aortic Valve Stenosis

  • diameter of aortic valve opening is reduced
  • aortic pressure pulse is decreased significantly

Atherosclerosis

Patent Ductus Arteriosus
-half or more of cardiac output flows back into pulmonary artery and lung blood vessels
-diastolic pressure falls very low before next heartbeat
>because blood is being shunted away from the aorta

Aortic Regurgitation

  • aortic valve is absent or will not close completely
  • aortic pressure may fall to 0 between heartbeats
31
Q

Look over figure 15-4: aortic pressure pulse contours in arteriosclerosis and other pathologies.

A

Help to understand objective 2

32
Q

Does diastolic or systolic have more of an effect on the mean arterial pressure?

A

Diastolic has more effect on mean pressure.

*refer to figure 15-8 if more understanding is needed.

33
Q

How is mean arterial pressure calculated?

A

MAP = diastolic pressure + 1/3 pulse pressure

34
Q

What is the calculation of mean arterial pressure not the simple average of diastolic and systolic pressures?

A

Because a greater fraction of the cardiac cycle is spend in diastole than in systole.

35
Q

What is meant by the “damping of the pressure pulses”?

A

Changes in pressure pulse as pulse wave travels toward smaller vessels.

36
Q

True or False:

Pressure in the right atrium refers to the central venous pressure.

A

True

37
Q

Why is the ability of the heart to pump blood out of the right atrium/ventricle one of the regulating factors of right atrial pressure?

A

Because the more blood that is pumped out of the right side of the heart to the lungs, means that there will be more blood coming into the right side of the heart. Thus, the more blood returned to the heart increases stroke volume.

Remember: what determines stroke volume is the amount of blood that returns to the heart.

Dr. Anderson -> “what the heart gets, it pumps out”

38
Q

Does increasing venous return to the right atrium increase right atrial pressure?

A

Yes, of course it does, but think more about secondary aspects that increases the venous return.

e.g., increased blood volume, dilation of arterioles, increased large vessel tone.

39
Q

If somebody is supine, and knowing that large veins have some resistance, how much greater much the pressure (mmHg) be in peripheral veins when compared to the right atrial pressure to return blood to the right atrium?

A

+4 to +6 mmHg

40
Q

Look-over figure 15-9 and 15-10 and 15-11

A

Hope everyone’s studies are going well!

41
Q

Fill in the Blank:

Our circulatory system is able to increase or decrease _______ to regulate right atrial pressure as volume changes.

A

COMPLIANCE

*refer to Figure 15-2 for explanation if needed.

42
Q

Arterioles are highly muscular vessels, but in which arteriole is the continuous muscular coat lost?

A

metarterioles

43
Q

What is a pre-capillary sphincter?

A

A smooth muscle fiber that encircles a capillary at the point where it originates from a metarteriole.

44
Q

What are the characteristics of a capillary wall?

A
  • unicellular layer of endothelial cells
  • thin basement membrane
  • total wall thickness = 0.5 micrometers
  • internal capillary diameter = 4-9 micrometers
45
Q

Do true capillaries have any smooth muscle?

A

NO

46
Q

Is there smooth muscle in venules?

A

YES

47
Q

What is the function of slit pores found in capillaries?

A

To allow for rapid diffusion of water, water-soluble ions, and small solutes.

48
Q

What are the plasmalemmal vesicles in capillaries formed from?

A

Formed from Caveolins

49
Q

Give examples of where in the body you can find capillaries that have pores?

A

Liver
GI Tract
Kidneys

50
Q

Describe the MOST important factor that regulates vasomotion?

A

Concentration of Oxygen in the Tissues

**This is objective 7

51
Q

True or False:

Diffusion is the least important means for the exchange of substances between the blood and the interstitial fluid.

A

False - diffusion is the MOST important

52
Q

Since non-lipid-soluble substances cannot readily diffuse across the capillary cell membrane, how do they get across?

A

Diffuse through the intercellular pores/clefts.

53
Q

True or False:

The rate of water diffusion through the capillary membrane is 80x faster than flow of plasma within the capillary.

A

True

54
Q

Fill in the Blank:

The rate of _______ is directly proportional to concentration differences of the _________ substance.

A

Diffusion ; Diffusing

55
Q

Why is the passage of substances through the interstitium mostly via diffusion rather than flow?

A

Because of large number of proteoglycan filaments, it is difficult for fluid to flow easily through the tissue gel.

56
Q

What forces determine the direction of diffusion into or out of a capillary?

A

Starling forces

57
Q

The sum of which 4 forces equals the net filtration pressure?

A

Capillary Pressure (outward force)
Interstitial Fluid Pressure (inward force)
Capillary Plasma colloid Osmotic Pressure (inward force)
Interstitial Fluid Colloid Osmotic Pressure (outward force)

58
Q

Which two Starling forces make up hydrostatic pressure?

A

Capillary Pressure (outward force) and Interstitial Pressure (inward force)

59
Q

Is the capillary plasma colloid osmotic pressure and inward or outward force?

A

Inward Force

60
Q

Capillaries that vary by the number and size of pores would have what difference?

A

Would all have a different capillary filtration coefficient (Kf).

61
Q

How do you calculate filtration?

A

Filtration = Kf x NFP

62
Q

How is a light negative pressure created in the interstitial spaces?

A

When fluid enters the lymphatics, the lymph vessel walls contract momentarily and pump fluid into the blood circulation.

63
Q

What Starling force acts to move fluid inward at the arterial end of the capillary?

A

Plasma colloid osmotic pressure (28 mmHg)

64
Q

Which 3 Starling forces move fluid outward at the arterial end of the capillary?

A

Capillary pressure (30 mmHg)
Negative Interstitial free fluid pressure (3 mmHg)
Interstitial fluid colloid osmotic pressure (8 mmHg)

65
Q

If the total outward force is 41 mmHg and the total inward force is 28 mmHg, what is the net outward force?

A

13 mmHg

66
Q

At the venous end of the capillary, which Starling force moves fluid inward?

A

Plasma colloid osmotic pressure (28 mmHg)

67
Q

At the venous end of the capillary, what forces are acting to move fluid outward?

A
capillary pressure (10 mmHg)
Negative interstitial free fluid pressure (3 mmHg)
Interstitial fluid colloid osmotic pressure (8 mmHg)
68
Q

What is the total inward force at the venous end of a capillary if the total outward force is 21 mmHg and the net inward force is 7 mmHg?

A

28 mmHg

69
Q

The net inward force is also known as what?

A

Net Reabsorption Force

70
Q

What are some factors that increase lymph flow (and also interstitial fluid pressure)?

A

elevated capillary hydrostatic pressure
decreased plasma colloid osmotic pressure
increased interstitial fluid colloid osmotic pressure
increased permeability of capillaries

71
Q

How do you calculate the rate of lymph flow?

A

(interstitial fluid pressure) x (activity of lymphatic pump)