Microcirculation

Question 1

anomalous viscocity

Answer 1

increase in viscosity at low flow rate

Question 2

formation of Rouleaux affect on flow

Answer 2

at low flow rates, blood appears to have a higher resistance than at faster flow rates

Question 3

Fahraeus-Lindqvist effect

Answer 3

viscosity of blood depends on the diameter of the tube

Question 4

axial streaming

Answer 4

tendency of RBCs to accumulate in the rapidly flowing axial lamina

Question 5

Rouleaux

Answer 5

chain-like aggregates of RBCs which form at low flow rates

Question 6

plasma skimming

Answer 6

tendency of the cell free plasma to be skimmed off at a branch point of the microcirculation

Question 7

cellular deformability

Answer 7

ability of the cell membrane to bend affecting flow in the microcirculation

Question 8

four factors that determine the diffusion rat of a substance between blood and interstitial fluid

Answer 8

concentration difference, surface area for exchange, diffusion distance, permeability of the capillary wall to the diffusing substance

Question 9

chemical potential

Answer 9

measure of the free energy of a solution, presence of solute on one side of the membrane lowers the chemical potential

Question 10

osmotic pressure

Answer 10

given as the hydrostatic pressure needed to balance the movement of solute

Question 11

net shifts in fluid between capillary and interstitial compartments are important for

Answer 11

maintenance of blood volume, interstitial fluid absorption, tissue edema formation, saliva production, sweat production, urine production

Question 12

transcellular fluid movement

Answer 12

across the cells

Question 13

paracellular fluid movement

Answer 13

between the cells

Question 14

net filtration pressure

Answer 14

difference between the hydrostatic and osmotic pressure differences

Question 15

hydraulic conductivity

Answer 15

constant of proportionality that relates the amount of flow to the net driving force

Question 16

capillary hydrostatic pressure (Pc)

Answer 16

varies among different tissues, influenced by gravity, higher Pc favors filtration. Is 35 mm Hg at arteriolar end and 15 mm Hg at venous end.

Question 17

effect of arteriolar and venular constriction and dilation on capillary hydrostatic pressure

Answer 17

constriction increases capillary hydrostatic pressure, dilation decreases capillary hydrostatic pressure.

Question 18

capillary colloid osmotic pressure

Answer 18

exerts a force that favors fluid absorption, due to proteins plus the excess salt

Question 19

interstitial fluid hydrostatic pressure

Answer 19

exerts force that drives fluid filtration in loose tissues, exerts force that drives fluid absorption in rigid enclosed compartments (bone marrow or brain)

Question 20

interstitial fluid osmotic pressure

Answer 20

exerts force that drives filtration

Question 21

starling equation predicts

Answer 21

filtration at the arteriolar end and absorption at the venular end of most capillary beds

Question 22

lymphatic system

Answer 22

similar to capillaries but with one way valves, pathway for larger molecules to reenter circulatory system

Question 23

edema

Answer 23

excess salt and water in interstitial spaces

Question 24

lymphatic blockage

Answer 24

malignant neoplasms may cause local edema upstream of the sites of blockage