Cell types one touching CSF the other touching plasma Given

Cell types: one touching CSF, the other touching plasma

Given that both cell types contain 5mM protein (using a lumped average molecular weight of 70 kD (70,000 g/mole), which cell type has a greater osmotic gradient due to protein alone?

Solution

Concentration of protein- 5mM = 5 x 18 = 90mg/dL

Osmotic gradient of cell type touching CSF= 45-75mg/dL

Osmotic gradient of cell type touching plasma=( -5910)- (-7910) mg/dL

Hence, osmotic gradient of cell type touching CSF is more.