BME 2101 Test 3 Guide With
Complete Solution
Direction of blood flow - ANSWER arteries, arterioles, capillaries, venules,
veins
Diameter of arterioles - ANSWER 10-15 micrometers
Diameter of capillaries - ANSWER 5-9 micrometers
Pressures from highest to lowest? (capillary, arteriole, venular) - ANSWER
highest=ateriolar
middle=capillary
lowest=venular
equation for flow resistance? - ANSWER (8*mu*L)/(pi*a^4)
flow resistance is most sensitive to which parameter? - ANSWER vessel radius
radius increases, flow decrease
radius decreases, flow increases
what is the continuous smooth muscle layer? - ANSWER wraps around
arterioles to regulate vessel diameter
vasodilation or vasoconstriction
how are pressure and resistance related? - ANSWER directly proportional
"resistance vessels" - ANSWER arterioles
,"blood volume storage vessels" - ANSWER veins
function of capillaries - ANSWER to exchange of materials such as oxygen &
carbon dioxide between plasma and interstitial fluid
why is the rate of diffusion of solutes faster in the kidneys than in the brain?
- ANSWER leaky junctions vs tight junctions
how to measure rate of solute diffusion across capillaries - ANSWER mass
flux
Fick's 1st Law
J=-P*delta c
(mass flux = permeability * concentration gradient)
equation for net filtration pressure - ANSWER NFP = Pc - Pif - (PIc - PIif)
+NFP - ANSWER change in fluid pressure is greater than change in osmotic
pressure, fluid pressure inside the capillaries is greater than outside, fluid
flows from high pressure to low pressure, so fluid will flow out of capillaries
-NFP - ANSWER change in osmotic pressure is greater than change in fluid
pressure, osmotic pressure inside the capillaries is greater than outside the
capillaries, water moves from low pressure to high pressure, fluid will flow
into the capillaries
equation used to show osmotic pressure - ANSWER vant hoff's law
pi = phi * i * c * R * T
overall, does water move into or out of capillaries? Is this filtration or
absorption? - ANSWER out of capillaries because fluid pressure is greater
than osmotic pressure, so NFP will be positive. this is called filtration
, net filtration rate equation - ANSWER starling hypothesis
net filtration rate = Kf * NFP
what prevents edema? - ANSWER the fluid is taken in by the lymph vessels
and returned to the circulation
why do feet swell on plane? - ANSWER lymph pump isn't working to drain
interstitial fluid
Possible pathways for solute transport across capillary walls? - ANSWER
diffusion through intercellular clefts, transcytosis using caveolae, diffusion
through fenestrae, diffusion through cell membranes and cells
What is Starling's Law of filtration? - ANSWER the rate of fluid movement
across the capillary wall as a function of the balance between hydrostatic and
osmotic pressures
What is most of the interstitial colloid osmotic pressure due to? - ANSWER
The plasma protein albumin
In general, physiological hydrostatic pressure gradients tend to push fluid...?
- ANSWER from the capillaries into the interstitial fluid
What increases lymph flow? - ANSWER muscle pump activity, increased
interstitial fluid pressure, coordinated contraction waves of smooth muscle in
the wall of lymphatic vessels
What is edema caused by? - ANSWER accumulation of fluid in the
interstitium
what is autoregulation - ANSWER keeping flow rate constant over a range of
pressures
Complete Solution
Direction of blood flow - ANSWER arteries, arterioles, capillaries, venules,
veins
Diameter of arterioles - ANSWER 10-15 micrometers
Diameter of capillaries - ANSWER 5-9 micrometers
Pressures from highest to lowest? (capillary, arteriole, venular) - ANSWER
highest=ateriolar
middle=capillary
lowest=venular
equation for flow resistance? - ANSWER (8*mu*L)/(pi*a^4)
flow resistance is most sensitive to which parameter? - ANSWER vessel radius
radius increases, flow decrease
radius decreases, flow increases
what is the continuous smooth muscle layer? - ANSWER wraps around
arterioles to regulate vessel diameter
vasodilation or vasoconstriction
how are pressure and resistance related? - ANSWER directly proportional
"resistance vessels" - ANSWER arterioles
,"blood volume storage vessels" - ANSWER veins
function of capillaries - ANSWER to exchange of materials such as oxygen &
carbon dioxide between plasma and interstitial fluid
why is the rate of diffusion of solutes faster in the kidneys than in the brain?
- ANSWER leaky junctions vs tight junctions
how to measure rate of solute diffusion across capillaries - ANSWER mass
flux
Fick's 1st Law
J=-P*delta c
(mass flux = permeability * concentration gradient)
equation for net filtration pressure - ANSWER NFP = Pc - Pif - (PIc - PIif)
+NFP - ANSWER change in fluid pressure is greater than change in osmotic
pressure, fluid pressure inside the capillaries is greater than outside, fluid
flows from high pressure to low pressure, so fluid will flow out of capillaries
-NFP - ANSWER change in osmotic pressure is greater than change in fluid
pressure, osmotic pressure inside the capillaries is greater than outside the
capillaries, water moves from low pressure to high pressure, fluid will flow
into the capillaries
equation used to show osmotic pressure - ANSWER vant hoff's law
pi = phi * i * c * R * T
overall, does water move into or out of capillaries? Is this filtration or
absorption? - ANSWER out of capillaries because fluid pressure is greater
than osmotic pressure, so NFP will be positive. this is called filtration
, net filtration rate equation - ANSWER starling hypothesis
net filtration rate = Kf * NFP
what prevents edema? - ANSWER the fluid is taken in by the lymph vessels
and returned to the circulation
why do feet swell on plane? - ANSWER lymph pump isn't working to drain
interstitial fluid
Possible pathways for solute transport across capillary walls? - ANSWER
diffusion through intercellular clefts, transcytosis using caveolae, diffusion
through fenestrae, diffusion through cell membranes and cells
What is Starling's Law of filtration? - ANSWER the rate of fluid movement
across the capillary wall as a function of the balance between hydrostatic and
osmotic pressures
What is most of the interstitial colloid osmotic pressure due to? - ANSWER
The plasma protein albumin
In general, physiological hydrostatic pressure gradients tend to push fluid...?
- ANSWER from the capillaries into the interstitial fluid
What increases lymph flow? - ANSWER muscle pump activity, increased
interstitial fluid pressure, coordinated contraction waves of smooth muscle in
the wall of lymphatic vessels
What is edema caused by? - ANSWER accumulation of fluid in the
interstitium
what is autoregulation - ANSWER keeping flow rate constant over a range of
pressures
