Physiology: Cellular

Question 1

Diffusion (Fick’s Law)

Answer 1

Q (rate of diffusion)= kp * (A/T) * (C1-C2)

kp= Permeability Constant proportional to - solubility / v(molecular weight)
A=Area
T= Thickness of membrane
C1-C2= concentration gradient

Question 2

Total Blood Volume

Answer 2

= Plasma Volume *100 / (100- Haematocrit)

Question 3

Measurement of Fluid Compartments

Answer 3

Volume of Compartment= mass of indicator/ conc. in compartment

Total Body Water- Deuterium Oxide
Extracellular Fluid- Inulin
Plasma- Radioactive Albumin or Evan’s Blue
Interstitial Fluid= ECF- Plasma
Inter-cellular fluid= TBW- ECF

Question 4

Plasma Osmolality (mosm/kg H20)

Answer 4

= 2(Na) + glucose + urea

Question 5

Gibbs Donnan

Answer 5

Cation A * Anion A= Cation B * Anion B

Question 6

Anion Gap

Answer 6

= (Na + K) - (Cl + HCO3)
4-12

Question 7

Nernst Equation

Answer 7

Wall Potential (mV) = (R*T/F*Z_(ion)) * log_e(ion_(in)/ion_(out))

R= Universal Gas Constant

T= Absolute Temp

F= Faraday Constant

Z=Valency

Question 8

Starling Forces

Answer 8

Rate of Filtration = K*(P_(cap)-n_(Int))-(P_(Int)-n_(cap))

K= Albumin Constant

P= Hydrostatic Pressure

n= Oncotic Pressure

Cap- capillary

Int- Interstitial