Microcirculation Flashcards
1
Q
the microcirculation is important b/c it is the site of
A
waste product removal, transport of nutrients to tissues
2
Q
arteries branch into more arteries which branch into
A
nutrient arteries
3
Q
nutrient arteries branch into
A
arterioles
4
Q
arterioles branch to
A
terminal arteriole
5
Q
off of terminal arteriole are
A
capillaries
6
Q
b/w arterioles and capillaries are
A
precapillary sphincters
7
Q
precarpillary sphincters regulate what
A
where blood goes in microcirculation
8
Q
as you go to smaller arteries what happens to blood flow
A
it is slow
9
Q
do capillaries have smooth muscle cells
A
no
10
Q
capillary structure
A
single layer epithelial cells w/ basement membrane, small diameter
11
Q
b/w endothelial cells in capillaries are
A
intercellular clefts
12
Q
what are intercellular clefts
A
basically pores - space b/w cells
13
Q
how do solutes and water move across capillary wall
A
intercellular cleft or plasmalemma vesicles
14
Q
what kind of “pore” in brain
A
blood brain barrier
15
Q
blood brain barrier, the endothelial cells have
A
tight junctions
16
Q
tight junctions in brain allows
A
water to move but pretty much nothing else
17
Q
liver pores, describe
A
very wide b/w endothelial cells
18
Q
why are the pores in liver so wide (b/w endothelial cells)
A
liver job is to detoxify stuff, so you want everything to be able to get into liver
19
Q
describe capillary endothelial in GI
A
pretty big pores, not as big as liver, not as small as muscle
20
Q
kidney arrangement of pores for capillaries
A
fenestrated pores that penetrate to middle of endothelial cells
21
Q
only system in body to have two capillary systems
A
kidney
22
Q
kidney microcirulation allows filtering of: what and no filtering of
A
filtering of water, small molecules like glucose, but not proteins
23
Q
you shouldn’t have what in your urine
A
proteins
24
Q
all capillaries in body are not always
A
open
25
capillaries open and close depending on
tissue needs
26
vasomotion:
intermittent bloodflow through individual capillaries
27
when do capillaries open
when a lot of oxygen is being used up, the capillaries sense it and the sphincters open
28
b/c some capillaries are open and some closed, when we talk about capillary flow we talk about
the average of it all - so average blood flow, average pressure, etc
29
how do substances move from capillaries into interstitial (or vice versa)
diffusion
30
what is diffusion
random movement
31
what is net diffusion
goes from high concentration to low concentration
32
how do lipid soluble substances diffuse through capillaries
they just go right through the cell membrane
33
how do water soluble substances cross the capillaries
they have to go through the pores in the capillaries
34
the lower the permeability, how do they cross membrane
the harder it is for them to cross the membrane
35
how easily can water cross capillary and why
easily, it has a higher permeability
36
how easily can albumin cross capillary and why
difficult time, it is bigger than pore, they have low permeability
37
for water soluble the net rate of diffultion is proportional to what three things
concentration difference b/w the two sides of the membrane
size of the molecule
size of the pore
38
space b/w cells is called
interstitium
39
what fills the interstitium
interstiial fluid
40
what solid structures is in interstitium
collagen and proteoglycan
41
what is in proteoglycan
hyaluronic acid
| proteins
42
interstitial fluid has same constituents as plasma except for:
lower concentrations of proteins
43
if you change ionic concentration of extracellular fluid (like making plasma hyperkalemic, high potassium) what will happen to potassium concentrations in interstitial fluid
it will also increase
44
what makes the extracellular fluid gell-like
the fluid is trapped in space among proteoglycan filaments
45
edema formation, you will increase what
free fluid in interstitial fluid
46
why does area swell, like with bee sting
fluida re moving into insterstitial fluid causing pockets of free fluid
47
in add'n to diffusion, what else is there in regards to movement across capillaries
filtration
48
what do you need to filter something
pressure
49
what four forces determine which way fluid moves
hydrostatic forces: capillary pressure & interstitial fluid
osmotic forces: plasma colloid osmotic pressure & interstitial fluid colloid osmotic pressure
50
what are the hydrostatic forces
capillary pressure
| interstitial fluid pressure
51
capillary pressure is what
pressure of blodo in capillary
52
capillary pressure tends to move fluid which direction
out of capillary through the pores
53
interstitial fluid pressure if positive
pushes fluids into capillary
54
interstitial fluid pressure if negative
pulls fluids out of capillary
55
what are the two osmotic pressures
plasma colloid osmotic pressure
| interstitial fluid colloid osmotic pressure
56
plasma colloid osmotic pressure:
pressure inside the capillary opposing filtration
57
colloid means
substance is bigger than what will just go through membrane
58
interstitial fluid colloid osmotic pressure:
trying to pull fluids out of the capillary
59
net filtration pressure depends on
average of all four of the forces acting on the capillary
60
what is the net filtration pressure equation
NFP) = Pc +/- Pif - pi p + pi if
61
what does NFP stand for
net filtration pressure
62
what does Pc stand for
capillary pressure
63
what does Pif stand for
interstitial fluid pressure
64
whatdoes pi p stand for
plasma colloid osmotic pressure
65
what does pi if stand for
interstitial fluid colloid osmotic pressure
66
all edema formation is
more fluids are filtered out than can be taken away, and they accumulate
67
what determines net filtration, how much totally filters out has to do with:
NFP and Kf
68
what is Kf
capillary filtration coefficient
69
what is capillary filtration coefficient, what does it tell you?
how many capillaries are open
| number and size of pores in each capillary
70
if more capillaries are open, what happens to filtration
more filtration
71
liver vs kidney what will be easier to filter stuff out of
liver - big gaps are bigger
72
Kf is higher in kidney, skin, muscle, or liver
liver
73
where would you have the greatest net filtration: muscle, or in the liver?
liver
74
Net filtration = ? (equation)
NFP x Kf
75
capillary pressure is very
low
76
capillary presure at venous end is
10 mm Hg
77
capillary pressure at arterial end is
30 mm Hg
78
interstitial fluid pressure is always negativ with respsect to
tissue that surrounds it
79
interstitial fluid pressure is always
negative
80
osmosis is
net movement of water
81
higher concentration of solute dissolved in water, the more
osmotic pressure is going to exert
82
under normal conditions plasma protein concentration s about
7.3 g/dL
83
in capillary have the oncotic agents drawing water in b/c most proteins can't
fit through the membrane/pores
84
plasma colloid osmotic pressure is about
28 mm Hg
85
to stop water moving into capillary you would have to
push out at 28 mm Hg
86
80% of collois osmotic pressure proteins is due to
albumin
87
average concentration of interstitial fluid colloid osmotic pressure is
3 g/dl
88
is average colloid osmotic pressure higher in liver or muscle
liver
89
arterial end of capillary, capillary pressure is about
30 mm Hg
90
what kind of interstitial pressure in arterial end of capillary
negative
91
total outward force in arterial end of capillary
41
92
forces moving fluid inward in arterial end of caiplary is
plasma colloid osmotic pressure
93
arterial end of capillary, ther eis net
filtration - fluids are filtered out
94
venous end of capillary, what is only thing that changes from arterial end
capillary pressure is much less, 10 instead of 30
95
what is capillary pressure at venous end of capillary
10
96
in venous end of capillary there is net
reabsorption
97
filtered vs reabsorption in capillary
morst filtered in arterial end most reabsorbed in venous end
98
excess fluid and proteins are picked up by
lymph vessels
99
not all fluid is reabsorbed by venous end, the excess is picked up by
lymph vessels
100
what could increase the netfiltration of fluids in tissue?
increase capillary pressure
101
anything that increases capillary pressure will increase
the forces moving fluids out
102
what would increase capillary pressure (generally)
more blood through a capillary
103
if right side of heart begins to fail what happens to venous pressure
increases (check)
104
if right atrial pressure is 20, is venous end capillary pressure 10?
no b/c then there would be no blood flow, all the capillary pressure has to increase
105
anything that affects venous pressure will also affect
capillary pressure
106
if pressures get higher what happens to filtration ratio in capillaries
increase
107
if pressures get higher what happens to filtration ratio in capillaries what does it do regarding fluid
extra - might get edema
108
left side heart failure and tries to exercise, and left heart can't keep pumping out enough blood for body and eight heart pumps out a lot, how do they die?
fluid going out so much they have pulmonary edema
109
what else might increase filtration besides capillary pressure (body wise)
if the proteins decrease (albumin) then you wouldn't be able to keep the fluids int he vessel
110
if you lose protein in urine and protein concentrations start to fall, say it goes from 28 to 15, what happens to fluid movement?
they will increase everywhere in body, they will move out of vessel and will get edema everywhere
111
bodywise if you take pressure from capillaryes everywhere in body what will you see
total outward force is about 28.3 and total inward is a little less, 28, so:
net outward force everywhere in body
112
net outward force everywhere in body means
there is net filtration everywhere in body
113
how much net filtration per minute
2 ml/min
114
how much per minute is filterting out of all blood vessels in body
2 ml /min
115
when blood circulates throughout your whole body there is excess filtration of about
2 ml /min
116
2 ml/min has to be picked up or else it will
accumulate
117
what picks up the excess filtration, drains the tissues?
lymphatic system
118
accessory route through which fluid, proteins and large particulate matter can flow from the interstitial spaces into the blood: what is this
lymphatic system
119
only what are reabsorbed back into vessles (liek venuous end)
only fluids, not proteins
120
if proteins are filtered out of capillaries they can't be
reabsorbed
121
only way proteins can be reabsorbed back into system are through
lymphatics
122
lymph flows ____ from a tissue
away
123
lymph goes where
right lymphatic durct or thoracic duct
124
what is the largest lymph vessel in body
right lympahtic
125
lymph vessles drain into
right and left subclavian veins
126
if lymph vessel gets clogged you will see
edema formation in that leg b/c the edema is not drained
127
endothelial cells of lymph have
flaps on them
128
the flaps (endothelial valves) on the lymph can
open and allows large proteins to enter
129
permeability of lymph capillaries
very high
130
what tissues have greatest amount of lymph flow
liver and intestines
131
what tissue has most concentration of proteins in lymph
liver
132
as there is more water in interstitial fluid, what happens to lymph flow
increases
133
the more stuff is filtered out, the more lymph
flow increases
134
what happens at lymph plateau if we continue to increase filtration?
edema
135
when lymph becomes saturated,any further increase in filtration out of capillaries produce
edema
136
review pg 32
32
| understand why elecated capillary presure would increase lymph flow, etc
137
hemorrhage how would that change lymph flow
capillary pressure decreased so lymph flow will change to net reabsorption to try to make up for lost fluid and try to increase blood volume so individual can live
138
severe dehydration does what to lymph flow
changes from net filtration to net reabsorption
139
vasodilator will do what to caipllary pressure
increase
140
histamine does what
increase permeability of capillary & is vasodilator
141
what does EPI do
open airways, consstrict vessels, increase pumping of heart
142
lymphatics have ___ and ____ Just like veins
pumps and valves
143
review pg 34
34
