Nephron Microscopic Anatomy

()Map THE NEPHRON (Map)

Glomerulus

Histology section of a normal renal corpuscle (© RVC 2008)

Histology section of a normal renal corpuscle (© RVC 2008)

Histology section of a normal renal corpuscle showing the layers of the bowmans capsule (© RVC 2008)

• Made up of many parallel capillaries
• These capillaries do not connect to venules as with other capillaries
• Blood flows into these capillaries through a wide afferent arteriole and leaves through a narrower efferent arteriole
• The flow from the efferant arteriole enters the peritubular capillaries surrounding the Proximal Tubule
• This change in diameter maintains a high filtration pressure which is essential for filtration
• Also the blood entering the afferent arteriole is at very high pressure already as it from the renal artery
• The pressure actually forces molecules through the glomerular filtration barrier which is responsible for selectively filtering the blood forming the glomerular filtrate.
• As well as the the cells in the blood vessels the other component of the glomerulus are the mesangial cells:
  • These give support to the glomerulus
  • Maintain glomerular basal lamina

Bowmans Capsule

• Surrounds the capillaries of the glomerulus
• Has two layers
  • Inner visceral layer - Podocytes
  • Outer parietal layer
• It is here where the filtrate is collected before entering the proximal tubule