The microvilli on the luminal surface of each epithelial cell in the proximal tubule wall will:
A) form a brush border that increases absorptive surface area of the entire inner surface of the proximal tubule.
B) form an electrical gradient that drives the diffusion of negative ions from the filtrate into the interstitial fluid.
C) participate in the countercurrent mechanism, which allows the contents to flow in opposite directions.
D) increase the secretory surface area of the entire inner surface of the proximal tubule.

Question

Quizplus · Accepted Answer

Microvilli on the luminal surface of each epithelial cell in the proximal tubule wall form a brush border, which increases the absorptive surface area of the entire inner surface of the proximal tubule. This increased surface area allows for more efficient reabsorption of valuable substances from the filtrate, such as glucose and amino acids.

The Microvilli on the Luminal Surface of Each Epithelial Cell