A note on the Fisher-Parsons surface area formula in the light of mucosal fresh and dry weights of rat small intestine.

Abstract

With the exception of the oral end, the mucosal fresh weight (mg/cm segment) of rat small intestine can be calculated using the Fisher-Parsons formula for the mucosal surface area (cm2/cm segment) multiplied by a factor of five. The dry weight does not follow the surface area formula owing to the fact that the dry weight/fresh weight ratio is not constant along the whole small intestinal length, but decreases in the aboral segments.