Lincoln Scholars Program    Notes for Unit 5, Kidney

Misc. notices

TikTok one-minute anatomy lectures from AnatomyLove!   by Meadow Campbell, PhD, St. Louis University School of Medicine.   [These short videos can be viewed without using a TikTok app or account.]

Core concepts of histology.

Common patterns of tissue organization.

This "Notes for Unit 5" webpage will remain available on the web.

Pop-up help sessions with Prof. King are invited.

Kidney study guide  (Bullet points below are links to topics within the renal study guide.)

• Kidney as gland.  The kidney has the fundmental architecture of a gland, with branching ducts terminating in specialized secretory structures.  But under the microscope kidney and gland have markedly different appearances.  The kidney has glomeruli in place of glandular acini, and ducts occupy most of its bulk.
   

gland	kidney
gland (pancreas)	kidney (cortex)
gland (parotid)	kidney (cortex)

 

• Cortex / medulla.  The consistent spatial arrangement of glomeruli and tubules yields distinctly appearances for cortex and medulla.  (This cartoon nephron is not drawn to scale; a human kidney contains hundreds of thousands of nephrons.
  

  medulla	cortex

 

• The nephron.  One glomerulus along with its associated tubule constitutes one "nephron."  Each portion of the nephron has its own specialized function.

  

• Renal corpuscle.  Each component of a glomerulus is significant for normal renal function.  Recognizing each cell type visually is not as important as appreciating how all of these components work together and how departures from normal can interfere with that function.

 

• Fenestrated capillary endothelium,  filtration membrane,  and podocytes:  These elements of the glomerulus are responsible for ultrafiltration of blood plasma.

 

• Mesangial cells and matrix  Mesangial cells secrete the mesangial matrix (blue-black in these images), which helps support the glomerulus.  The images here show a pathological increase in the number of mesangial cells and the amount of matrix.

 

• Tubules  Renal tubules are differentiated into several specialized segments.  Recognizing each segment visually is not as important as appreciating its function.

 

• Vasculature  In the kidney, the arrangement of blood vessels has special functional significance.

 

• Pathology.  Several pathological processes interfere with glomerular filtration and thus have a critical impact on kidney function.  Diagnosis of renal pathology often involves biopsy and histological examination of renal cortex. 

 

Certain diagnostic details can be accentuated by special stains.  The thumbnail to right links to several images of such stains.   

Electron microscopy offers additional clarity.  A couple examples can be viewed at WebPath:

• Minimal change disease (MCD).  Note that podocytes form a continuous surface over the capillary; filtration slits are missing.
• Membranous nephropathy.  Basement membrane is thickened and includes electron dense deposits.
   

Additional renal pathology images are available at WebPath.  (This page is worth an extended visit, after you have become comfortable with basic kidney histology.)


• acute pyelonephritis. 
• chronic pyelonephritis. 
• "benign" nephrosclerosis. 
• nodular diabetic glomerulosclerosis. 
• nodular diabetic glomerulosclerosis, PAS stain.   

• Contents for traditional curriculum
   
• Image index for SIU Histology website
   
• If you have a taste for history, see Eponyms in histology.

SEARCH THE SITE:	WWW histology.siu.edu

 

Comments and questions: dgking@siu.edu

SIUC / School of Medicine / Anatomy / David King

https://histology.siu.edu//LincolnScholarsProgram/kidney-intro.htm
Last updated:  4 April 2023 / dgk