Microscopic Anatomy of the Nephron

Overview

• Focus on the structure of the nephron, not its function or urine concentration.
• Parts of the nephron are located in both the cortex and the medulla of the kidney.

Nephron Structure

• Cortex Components:
  • Glomerulus
  • Proximal Tubule
  • Distal Tubule
• Medulla Components:
  • Loop of Henle (dips into medulla and back to cortex)

Types of Nephrons

• Cortical Nephrons:
  • Superficial glomerulus
  • Shallow Loop of Henle
• Juxtamedullary Nephrons:
  • Glomerulus deeper, near medulla
  • Deeper Loop of Henle

Glomerulus

• Initial filtration site of blood.
• Contains a ball of capillaries.
• Arterioles:
  • Afferent Arteriole: Brings blood to the glomerulus.
  • Efferent Arteriole: Takes filtered blood away.
  • Remember order: Afferent (before) Efferent (A before E).

Tubules

• Proximal Convoluted Tubule (or Proximal Tubule)
• Loop of Henle:
  • Thick Descending Limb
  • Thin Descending Limb
  • Thin Ascending Limb
  • Thick Ascending Limb
• Distal Convoluted Tubule
  • Lies near the glomerulus and arterioles.
  • Contains the Juxtaglomerular apparatus (covered in next tutorial).
• Collecting Duct:
  • Connects to distal tubule.
  • Transports urine to the renal papilla.

Nephron Vasculature

• Efferent Arteriole: Supplies blood to two capillary beds.
  • Peritubular Capillaries: Supply proximal and distal tubules.
  • Vasa Recta: Supplies Loop of Henle.
• Capillaries provide water and solutes to filtrate, and reabsorb from the kidney.

Next Steps

• Upcoming tutorial will cover the glomerulus in more detail, including cell types and their functions.

Additional Resources

• Visit handwrittentutorials.com for more tutorials and PDF resources.