Structures of the Kidney and Nephron

Overview

• The lecture covers the anatomy of the kidney and nephron structures.
• Focus on the parts of the kidney, blood flow, and the nephron.

Kidney Structure

Outer Layer

• Renal/Fibrous Capsule: Surrounds the outside of the kidney.

Internal Layers

• Renal Cortex:
  • Outer tissue layer.
  • Contains renal columns.
• Renal Medulla:
  • Inner tissue core.
  • Contains renal pyramids.

Renal Pyramids

• Point towards the renal papilla.
• Urine flows from renal pyramids to minor calyces.

Calyces and Renal Pelvis

• Minor Calyx:
  • Collects urine from renal pyramids.
  • Multiple minor calyces form a major calyx.
• Major Calyx:
  • Merges with others to form the renal pelvis.
• Renal Pelvis:
  • Central urine-collecting area.

Renal Sinus

• Composed of minor calyces, major calyces, and renal pelvis.

Blood Flow in the Kidney

Arterial Supply

• Renal Artery: Main supply to the kidney.
• Segmental Arteries: Branches of the renal artery.
• Interlobar Arteries: Branches of segmental arteries between pyramids.
• Arcuate Arteries: Arc over the pyramids.
• Interlobular/Cortical Radiate Arteries: Branch from arcuate into the cortex.
• Afferent Arterioles: Carry blood to the glomerulus.

Venous Drainage

• Efferent Arterioles: Carry blood away from the glomerulus.
• Peritubular Capillaries/Vasa Recta: Associated with nephrons.
• Interlobular Veins: Collect blood from cortical veins.
• Arcuate Veins: Drain into interlobar veins.
• Interlobar Veins: Merge into renal vein (no segmental veins involved).

Nephron Structure

Renal Corpuscle

• Glomerulus: Ball of capillaries.
• Glomerular Capsule: Surrounds the glomerulus.
• Together, known as the renal corpuscle.

Tubular System

• Capsular Space: Collects filtrate from the glomerulus.
• Proximal Convoluted Tubule: First segment receiving filtrate.
• Nephron Loop (Loop of Henle): Extends into the medulla.
• Distal Convoluted Tubule: Further processes filtrate.
• Collecting Tubule/Duct: Receives processed filtrate leading to the renal pelvis.

Visual Aids

• The lecture references a kidney model and diagrams to demonstrate structures.
• Key vessel pathways and nephron segments are pointed out using a wooden probe.