Proximal Tubules

The kidney’s proximal tubule is the section of the nephron that extends from the renal pole of the Bowman’s capsule to the start of the Henle loop. The proximal convoluted tubule (PCT) and the proximal straight tubule are two other kinds. The brush border cell gets its name from the luminal surface of the epithelial cells that make up this region of the nephron, which is coated in densely packed microvilli that form a border that is clearly visible under a light microscope. The microvilli greatly expand the luminal surface area of the cell, which supports the lumen’s hypothesized flow sensing and reabsorptive activity. Mitochondria are widely distributed throughout the cytoplasm of the cells. The cells appear acidophilic due to the abundance of mitochondria. The active transport of sodium ions creates a gradient in concentration that allows the luminal side to enter the cell. The proximal tubule’s cuboidal epithelial cells appear to have no distinct cell borders because of their...