General Physiology

·         Darrow Yannet Diagram: that describe ECF,ICF graphically

·         Tonicity is the effect of osmolality on the cell size, not to concentration of solutes.(OSMOLALITY)

UREA: NO EFFECT ON TONICITY EVENTHOUGH INCREASE OSM.

GLYCEROL: CELL INITIALLY SHRINKS, THEN SWELLS.

·         Simple diffusion is described by the Fick equation.

Carrier-mediated diffusion, called facilitated diffusion, is described by the Michaelis-Menton equation.

·         The reflection coefficient is an index of the membrane’s permeability to the solute and varies between 0 and 1.

Particles that are impermeable to the membrane have a reflection coefficient of 1.

Particles that are freely permeable to the membrane have a reflection coefficient of 0.

·         The osmotic pressure (in units of mmHg) is calculated with the van’t Hoff equation:

          π = cRT

·         The equilibrium potential is calculated with Nernst’s equation.

The resting potential is calculated with the transference equation or with the Goldman equation.

·         Since the plasma volume is approximately 8% (1/12) of the total body water volume, only 8% of the ingested water will remain in the plasma. Therefore, of the 600 mL of water ingested, approximately 50 mL remains in the plasma, 150 mL enters the interstitium, and 400 mL enters the intracellular space.