The kidney is divided into 2 parts:  the cortex and the medulla.  The fundamental unit of the kidney is the nephron (review the parts of the nephron). The renal corpuscles are located in the cortex.  The medulla is made primarily of collecting ducts.
As a result, you can identify the cortex and the medulla based upon the presence or absence of the renal corpuscles.

Photo taken by T. Carrera

Cortex of Kidney (200x).  Renal corpuscles (circled in black) is a collective term for both the glomerular (Bowman's) capsule and a specialized capillary bed  (the glomerulus).  Both the glomerulus and the capsule are made of simple squamous epithelium.   Surrounding the corpuscles are multiple convoluted tubules (two of them are circled in blue) made of simple cuboidal epithelial tissue.  We may have used both of these structures as examples in the histology lab.  Renal corpuscles are only found in the cotex of the kidney.

Photo taken by T. Carrera

Kidney (400x) Renal corpuscles are circled in black. Surrounding the corpuscles are the convoluted tubules (three of them are circled in blue) made of simple cuboidal epithelial tissue.

Photo taken by T. Carrera

Renal Corpuscle (1000x) While we do not have microscopes that can obtain this magnification in lab, this image is useful because the components of the renal corpuscle are easy to label.  Once you have viewed them here, look at the previous slides and identify the structures there.  The black line is designating the basement membrane of the parietal layer of the glomerular corpuscle.  The green arrows are pointing some of the many nuclei of the simple squamous epithelium.  The yellow line encompasses both the visceral layer of the glomerular capsule and the glomerulus.  Remember, this is where filtration takes place.

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See the transitional epithelium in both the contracted and distended bladder.

Photo taken by T. Carrera

Distended bladder (200x)  The light blue arrow indicates the mucosa (transitional epithelium), the green bracket indicates the submucosa and the yellow bracket indicates the muscularis.