Clinical note: Kidney stones (nephrolithiasis) are concretions of calcium salts and uric acid that can form in the renal pelvis when urine contains high concentrations of substances such as calcium and uric acid. Small stones may pass down the ureters (with considerable pain) and larger stones can be destroyed by focused sound waves in a procedure called lithotripsy. (Photo courtesy of Dr. C.F. Verkoelen)

Trace the vasculature and microvasculature through the kidney in the diagram (Fig. 19-3) and indicate which vascular components are associated with specific regions and nephron components.

Examine the structures in the cortex and medulla in greater detail using the section of human kidney on slides 14 and 144.

• Study the diagram of a renal corpuscle (Fig. 19-5) and examine them on the slides to identify the simple squamous epithelium of Bowman's capsule, glomeruli, the large, pale podocytes (Fig. 19-14b).
• Study the electron micrographs of glomeruli (Figs. 19-5 and 19-6), identifying
  • Podocytes,
  • Capillary endothelial cells,
  • The intervening basement membrane, and
  • Bowman's space.
• Note especially the organization of the podocyte foot processes and the endothelial cells fenestrations at the basement membrane.
• On the slide look at many examples of glomeruli to find one cut to show one or both of the afferent or efferent arterioles (Fig. 19-5).

Describe the structural features which produce the process of renal filtration.

What is significance of having afferent and efferent arterioles in this process?

What drains Bowman’s space?

Next let's consider kidney infections and look at examples of he nephron.