BRS 1 equations

Question 1

Poisuilles law

Answer 1

8(viscosity x length)/πr^4

Question 2

relate cardiac output, total peripheral resistance/peripheral vascular resistance and MAP

Answer 2

MAP = Q x PVR

Question 3

calculate pulse pressure from SBP and DBP

Answer 3

PP = SBP-DBP

Question 4

calculate MAP from pulse pressure and DBP

Answer 4

MAP = DBP +1/3PP

Question 5

calculate pH

Answer 5

-log10[H+]

Question 6

calculate [H+]

Answer 6

10^-pH

Question 7

darcy’s law

Answer 7

pressure gradient = flow rate x resistance

Question 8

calculate cardiac output from MAP and TPR

Answer 8

Q = MAP/TPR

Question 9

calculate stroke volume from EDV and ESV

Answer 9

SV = EDV - ESV

Question 10

stroke volume units?

Answer 10

mL

Question 11

calculate ejection fraction

Answer 11

SV/EDV x 100

Question 12

calculate cardiac output

Answer 12

heart rate x stroke volume

Question 13

calculate stroke work

Answer 13

stroke volume x pressure

Question 14

law of laplace

Answer 14

wall tension = pressure in vessel x radius / thickness

Question 15

calculate from SBP and DBP

Answer 15

1/3SBP + 2/3DBP

Question 16

compliance

Answer 16

volume difference/pressure difference

Question 17

calculate transmural pressure

Answer 17

pressure inside - pressure outside

Question 18

calculate net ultrafiltration pressure

Answer 18

hydrostatic p in glom. - hydrostatic p in bowm. - oncotic p of glomerulus

Question 19

calculate glomerular filtration rate

Answer 19

net ultrafiltration pressure x ultrafiltration coefficient

Question 20

calculate renal clearance

Answer 20

conc in urine x rate of urine pro / conc in plasma

Question 21

units of renal clearance

Answer 21

mL/min

Question 22

calculate clearance ratio

Answer 22

conc. of substance/ conc of inulin

Question 23

calculate urine flow rate

Answer 23

volume/ time

Question 24

calculate filtration fraction

Answer 24

GFR/RPF

Question 25

calculate minute ventilation

Answer 25

tidal volume (L) x breathing frequency

Question 26

calculate alveolar ventilation

Answer 26

(tidal V - dead space) x breathing frequency

Question 27

nerst equation

Answer 27

equilibrium potential = RT/zF ln[X2]/[X1]

Question 28

goldman-hodgkin-katz equation

Answer 28

describes membrane potential using log concentration inside/outside and permeability to ions. multiplied by -61