Cortex: Convoluted portion

Renal corpuscles consist of the glomerular capillaries and Bowman’s capsule.  Bowman’s capsule is composed of two epithelial layers separated by Bowman’s space.  The epithelium of the visceral layer is modified to form podocytes, whose foot processes surround the capillaries forming the glomerulus.The parietal layer of the capsule is a simple squamous epithelium. 

Proximal tubules are lined by a tall, simple cuboidal epithelium with a brush border.  Because they are longer than distal tubules, more cross sections of proximal tubules will be seen in an image.  In this preparation, mitochondria did not fix well and, therefore, the cytoplasm of the cells, appears vacuolated. Also, a precipitate frequently fills the lumens of these tubules.

The proximal convoluted tubule begins at the urinary pole.  The urinary pole is the continuation of the simple squamous epithelium of the parietal layer of Bowman’s capsule with the epithelium forming the proximal convoluted tubule.  At the urinary pole, the filtrate accumulating in Bowman’s space enters the first tubular part of the nephron.

Distal tubules are lined by a simple cuboidal epithelium that is shorter than that in proximal tubules.  The epithelium also lacks a brush border, and the nuclei often appear irregularly spaced around the lumen.  Each lumen of a distal tubule is wider than that of a proximal tubule, even though its overall diameter is less.

Connecting tubules are lined by a simple cuboidal epithelium whose nuclei are evenly spaced around the tubule.  Connecting tubules connect the distal convoluted tubule with the collecting duct in the medullary ray.

Interlobular arteries are branches of arcuate arteries and travel through the convoluted portions of the cortex where they give off afferent arterioles supplying the glomerular capillaries.