Question

The removal of waste products during dialysis is  ___________

(a) inversely proportional to the concentration gradient across the membrane

(b) proportional to the concentration gradient across the membrane

(c) proportional to the flow rate across the membrane

(d) inversely proportional to the flow rate across the membrane

I had been asked this question by my college director while I was bunking the class.

Origin of the question is Digital Recorders topic in chapter Recording System of Biomedical Instrumentation

Answer 1

Correct choice is (b) proportional to the concentration gradient across the membrane

Easy explanation: The removal of waste products during dialysis is proportional to the concentration gradient across the membrane. In order to effect the maximum gradient, the concentration of waste products in the dialysate should be maintained at zero. This is achieved in most currently employed machines by using the dialysate only once and then discarding it.