Exam 2 – cardio Ch 16 Flashcards

1
Q

What is the function of microcirculation?

A

Important in the transport of nutrients to tissues
Site of waste product removal
Over 10 billion capillaries with surface area of 500-700 square meters perform function of solute and fluid exchange

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

How does the heart know how much blood to pump out of arteries?

A

How much venous blood flow returns

Heart pumps whatever comes to it

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

What is the structure of capillary wall?

A

Composed of unicellular layer of endothelial cells Surrounded by a basement membrane

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

What is the diameter of a capillary?

A

4-9 microns

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

How do solute and water move across capillary wall?

A

Intercellular cleft

By plasmalemma vesicles

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

What is the intercellular cleft?

A

Thin-slit, curving channel that lies at top of figure between adjacent endothelial cells

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

What do plasmalemma vesicles play a role in?

A

Endocytosis

Transcytosis

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

Why is it important that RBCs are biconcave?

A

Capillaries are smaller than RBCs so RBCs use concave characteristic and bend in order to move into capillary

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

What are the different types of capillaries?

A

Continuous
Fenestrated
Sinusoid

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

What are continuous capillaries?

A

Harder to get materials through

Continuous membrane

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

What are fenestrated capillaries?

A

A lot of fluid passes through

Ex: kidney

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

What are sinusoid capillaries?

A

Great big spaces
Nothing holding in blood
Ex: spleen

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

How does molecular size affect passage of molecules across the capillary wall?

A

The width of capillary intercellular slit pores is 6-7 nanometers
The permeability of the capillary pores for different substances varies according to their molecular diameters

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

What do capillaries in different tissues have extreme differences in?

A

Permeabilities

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

How do solutes and fluids cross the capillary wall?

A

Most important means by which substances are transferred between plasma and interstitial fluid is by diffusion

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

How do lipid soluble substances diffuse?

A

Directly through cell membrane of capillaries

CO2 and O2

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

How do lipid insoluble substances diffuse?

A

Cross capillary walls via intercellular walls

H20, Na, Cl, and glucose

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

What do concentration differences across capillaries enhance?

A

Diffusion

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

Look at relative permeability of muscle capillary pores to different-sized molecules chart

A

Look at relative permeability of muscle capillary pores to different-sized molecules chart

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

What is space between cells called?

A

Interstitium

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

What is fluid in the interstitium called?

A

Interstitial fluid

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

What are the two major types of solid structures in the interstitium?

A

Collagen fibers

Proteoglycan filaments

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

What are the purpose of collagen fibers in interstitium?

A

Provide most of tensional strength of tissues

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

What are proteoglycan filaments?

A

Coiled molecules composed of hyaluronic acid

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

What is almost all fluid in interstitium in the form of?

A

Gel

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

What is gel?

A

Fluid proteoglycan mixtures

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

Under normal conditions, is there a lot of free fluid?

A

No, very little free fluid

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

What is normal capillary hydrostatic pressure?

A

Approximately 17 mmHg

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

What is interstitial fluid pressure in most tissues?

A

Negative

30
Q

What type of pressures do encapsulated organs have?

A

Positive interstitial pressures

+5 to +10 mmHg

31
Q

What is negative interstitial fluid pressure caused by?

A

Pumping of lymphatic system

32
Q

What is colloid osmotic pressure caused by?

A

Presence of large proteins

Oncotic pressure

33
Q

What effect does presence of negative ions on proteins have on colloid osmotic effect?

A

Increased colloid osmotic effect of proteins

Donnan effect

34
Q

What is normal plasma colloid osmotic pressure?

A

28 mmHg

35
Q

What is normal plasma protein concentration?

A

7.3 g/dl

36
Q

What is the reflection coefficient of capillaries?

A

Quantitates the amount of protein that is reflected away from the capillary membrane

37
Q

What does the reflection coefficient of 1 mean?

A

All proteins are reflected and none pass through pores

38
Q

What does reflection coefficient of 0 mean?

A

Membrane is permeable to all proteins

39
Q

What are the determinants of net fluid movement across capillaries?

A

Hydrostatic capillary pressure
Hydrostatic interstitial pressure
Plasma colloid osmotic pressure
Interstitial fluid colloid osmotic pressure

40
Q

Define plasma colloid osmotic pressure

A

Oppose filtration causing osmosis of water inward through the membrane
Tends to cause osmosis of fluid inward through capillary membrane

41
Q

What are some factors that lead to changes in plasma colloid osmotic pressure?

A

Liver failure
Nephrosis
Dilutional

42
Q

Define interstitial fluid colloid pressure

A

Promotes filtration by causing osmosis of fluid outward through the membrane
Tends to cause osmosis of fluid outward through capillary membrane

43
Q

Define capillary hydrostatic pressure

A

Tends to force fluid outward through capillary membrane

44
Q

What are some factors that capillary hydrostatic pressure?

A

Decreases arteriole resistance
Increases venous pressure
Overall increased capillary hydrostatic pressure

45
Q

Define interstitial fluid pressure (Pif)

A

Opposes filtration when value is positive

Tends to force fluid inward through capillary membrane when Pif is positive but outward when Pif is negative

46
Q

What is interstitial fluid pressure in most tissues?

A

-3 mmHg

47
Q

What factors determine colloid osmotic pressure?

A

75% of total colloid osmotic pressure of plasma results from the presence of albumin and 25% is due to globulins

48
Q

What is interstitial protein concentration?

A

3 gm/dl

49
Q

What is the normal interstitial colloid osmotic pressure?

A

8 mmHg

50
Q

Define filtration rate

A

Net filtration pressure multiplied by the filtration coefficient

51
Q

Ddefine filtration coefficient

A

A product of surface area times the hydraulic conductivity of membrane

52
Q

How much of filtered fluid is reabsorbed on venous end?

A

90%

53
Q

Where is the remaining 10% of blood reabsorbed at?

A

Returned to circulation via lymphatics

54
Q

What are forces causing filtration at the arteriole end of the capillary?

A
Forces tending to move fluid outward 
-Capillary pressure 30 mmHg
-Negative interstitial free fluid pressure 3 mmHg 
-Interstitial fluid colloid osmotic pressure 8 mmHg
TOTAL OUTWARD FORCE 41 mmHG
Forces tending to move fluid inward
-Plasma colloid osmotic pressure 28 mmHg
TOTAL INWARD FORCE 28 mmHg
55
Q

What is the net outward force on arteriole end of capillary?

A
Summation of forces 
-Outward 41 mmHg
-Inward 28 mmHg 
NET OUTWARD FORCE 13 mmHg 
Tending to move fluid outward through capillary pores
56
Q

What are forces causing filtration at the venous end of the capillary?

A
Forces tending to move fluid outward 
-Capillary pressure 10 mmHg
-Negative interstitial free fluid pressure 3 mmHg 
-Interstitial fluid colloid osmotic pressure 8 mmHg
TOTAL OUTWARD FORCE 21 mmHG
Forces tending to move fluid inward
-Plasma colloid osmotic pressure 28 mmHg
TOTAL INWARD FORCE 28 mmHg
57
Q

What is the net outward force on arteriole end of capillary?

A
Summation of forces 
-Outward 21 mmHg
-Inward 28 mmHg 
NET OUTWARD FORCE 7mmHg 
Force causes fluid to move into capillary is greater than opposing reabsorption
58
Q

What are net starling forces in capillaries?

A

Mean forces tending to move fluid outward
-Mean capillary pressure 17.3 mmHg
Negative interstitial free fluid pressure 3 mmHg
-Interstitial fluid colloid osmotic pressure 38mHg
TOTAL OUTWARD FORCE 28 mmHg
Mean force tending to move fluid inward
-Plasma colloid osmotic pressure 28 mmHg
TOTAL INWARD FORCE 28 mmHg

59
Q

What is the summation of mean forces for net starling forces in capillaries?

A

Outward 28.3 mmHg
Inward 28 mmHg
NET OUTWARD FORCE 0.3 mmHg

60
Q

What is the net filtration pressure?

A

0.3 mmHg which causes a net filtration rate of 2mL/min for entire body

61
Q

What is the lympathic system an accessory route for?

A

Route by which fluid and protein can flow from interstitial spaces to the blood

62
Q

What is the lymphatic system important in?

A

Prevent edema

63
Q

What is the lymph derived from?

A

From interstitial fluid that flows into lymphatics

64
Q

What is the lymphatic system a major route for?

A

Absorption of nutrients from the GI tract

65
Q

What does the lymphatic system play an important role in?

A

Immune system

66
Q

What is the thoracic duct?

A

Whole system that delivers to your entire body and they tend to join together and go on either side of your venous system

67
Q

What are some causes of thoracic duct encounters?

A

A cat gets hit by a car

Taking blood samples from pigs

68
Q

How does the lymphatic pump affect lymph flow?

A

The degree of activity of the lymphatic pump

Smooth muscle filaments in lymph vessel cause them to contract

69
Q

What contributes to lymphatic pumping?

A

External compression

70
Q

How do changes in interstitial hydrostatic pressure affect lymph flow?

A

Increase interstitial fluid hydrostatic pressure which increases lymph flow

71
Q

What are the effects of increased lymph flow?

A

Elevated capillary hydrostatic pressure
Decreased plasma colloid osmotic pressure
Increased interstitial fluid colloid osmotic pressure
Increased impermeability of capillaries

72
Q

What could cause a late term pregnant mare to have pitting edema?

A

Caused by obstruction of abdominal veins, lymphatics, and proteins (albumin) in blood