hemodynamics

Question 1

as cross sectional area increases, velocity

Answer 1

increases

Question 2

olm - what two factors determine blood flow thru vessel

Answer 2

voltage diff and resistance. (PressureArterial - pVenous) / resistance.

Question 3

according to olm, increasing resistance ___ flow

Answer 3

decreases

Question 4

according to olm, increasing resistance ___ pressure

Answer 4

increases

Question 5

define BP

Answer 5

the force exerted by the blood against any unit area of the vessel wall

Question 6

conversion factor from mmHG to cmH20

Answer 6

1mm=1.36cm h20 pressure

Question 7

cerebral perfusion pressure

Answer 7

MAP - CVP or ICP (whichever is higher)

Question 8

what dose poiseullies law talk about

Answer 8

flow

Question 9

according to poissuellie, flow is ___ proportional to the pressure gradient

Answer 9

directly

Question 10

according to possueille, flow is ____ proportional to the radius

Answer 10

directly

Question 11

according to poiseuillie, flow is INDIRECTLY porportional to

Answer 11

viscosity and length

Question 12

***according to poiseulles law what factor has the greatest impact on the rate of blood flow thru a vessel

Answer 12

radius to 4th power

Question 13

if radius is tripled,

Answer 13

64 fold

Question 14

can resistance be measured directly

Answer 14

no

Question 15

SVR formula

Answer 15

MAP-CVP/ CO x 80

Question 16

PVR

Answer 16

MAP-PCWP / CO x 80

Question 17

blood vessels in series =

Answer 17

r1+r2+r3..

Question 18

blood vessels in parallel =

Answer 18

1/r1 + 1/r2 + 1/r3

Question 19

flow thru each of the parallel vessels is determined by

Answer 19

the pressure gradient and its own resistance

Question 20

if you add another blood vessel what happens to total vascular resistance

Answer 20

decreases

Question 21

laminar flow is most related to

Answer 21

viscosity

Question 22

turbulent flow is most related to

Answer 22

density

Question 23

laminar flow - blood near vessel wall is ___, blood in middle is ___

Answer 23

slow, fast

Question 24

what formula predicts laminar vs turbulent

Answer 24

reynolds. when its above 2000, turbulence usually occurs

Question 25

reynolds number formula

Answer 25

(density x tube diameter x mean velocity) / viscosity

Question 26

increasing hematocrit ____ viscosity

Answer 26

increases

Question 27

reduced hematocrit causes low viscosity, which causes ____ turbulence

Answer 27

high. because viscosity is indirectly related to reynolds number

Question 28

higher viscosity , ___ reynolds #

Answer 28

lower.. double check this

Question 29

as blood pressure increases within a vessel.. why does FLOW increase much greater than one would expect?

Answer 29

because of DILATION (arterial resistance down) and sympathetic stiumulation (increasing pa-pv gradient)

Question 30

flow takes the path of

Answer 30

least resistance.

Question 31

whats a predictor of when laminar flow becomes turbulent?

Answer 31

reynolds #