Question

1. It illustrates possible changes in red blood cell volume resulting in the change in the composition of extracellular fluid in a cell that was balanced at 150 mM/L NaCl at time 0

1. illustrates the volume caused by immersion in a 300 mOsm NaCl solution?

2. represents the volume change caused by immersion in an aqueous solution of 200 mOsm/L of NaCl and 200 mOsm/L glycerol? (NOTE: TWO DIAGRAM

Answer 1

Given, 150 mM/L NaCl solution is the balanced solution for the RBC.

To convert mM into mOsm, we need to multiply with the number of osmoles.

Each mole of NaCl becomes two osmoles in a solution: one osmole of Na+ and one osmole of Cl-.

150mM/L NaCl = 150 x 2 = 300 mOsm/L.

So, 150 mM/L or 300 mOsm/L NaCl solution is a balanced one for RBC.

There would be volume change only when there is a change in the concentration of a solution. Since there is no change in the concentration from 150 mM/L NaCl to 300 mOsm/L NaCl, there would be no change in the volume of the RBC.

However, when the cell is immersed in an aqueous solution of 200 mOsm/L NaCl and 200 mOsm/L glycerol, water from the cell moves out into the solution and gets shrunk since the solution is hypertonic to the cell.