1. Pathology of the Urinary System (Kidney, Urinary Tract, Bladder)

2. Plan: Lecture 1: Recap of anatomy and physiology, clinical aspects of renal disease, pathogenesis of glomerulonephritis Lecture 2:Morphologic expressions of glomerular injury, primary glomerular diseases Lecture 3:Primary glomerular disease

3. Introduction. Weight 150 g Cortex (1.5 cm) and medulla Renal pelvis - 2 to 3 major calyces - each 3-4 minor calyces.

4. Filters about 1700 L of blood to prepare 1 L of urine

5. Anatomical structure of parenchyma..  Lobe  Lobule  Cortex  Medulla

6. Anatomical structure of parenchyma.  Lobules  Cortex o Columns of Bertin  Medulla (O, I) o Pyramid o Papilla

7. The Cortex Labyrinth Medullary rays

8. Vasculature Renal artery - anterior and posterior br ---- interlobar ---- arcuate --- interlobular ---- afferent arteriole ---- glomerulus ---- efferent arteriole ---- peritubular capillaries ---- vasa recta ---- venous vasa recta ---- renal vein

9. Vascular structure of parenchyma

10. Renal vasculature Arteries are end arteries Glomerular diseases can compromise vascular supply to other components Medulla is relatively avascular and vulnerable to ischemia Cortex is more vulnerable to hypertensive changes

11. The Nephron

12. (Pathology) Compartments Glomeruli Tubules Interstitium Blood vessels

14. Glomerulus Formation Components Structure

15. Glomerulus Formation Components Structure Bowmans capsule Parietal epithelial cells Visceral epithelial cells Basement membrane Endothelial cells Mesangial cells Mesangial matrix

16. Glomerulus Formation Components Structure Bowmans capsule Parietal epithelial cells Visceral epithelial cells Basement membrane Endothelial cells Mesangial cells Mesangial matrix

17. Glomerulus Formation Components Structure Filtration membrane fenestrated endothelial cells (70-100 nm); glomerular Basement Membrane visceral epithelial cells -podocytes (20-30 nm)

18. Glomerulus Formation Components Structure Glomerular basement membrane: - Thick inner lamina densa - Lamina rara externa and interna. Collagen IV, laminin, polyanionic proteoglycans, intermediate filaments, other glycoproteins. Filtration is governed by size and charge.

19. The Glomerulus

21. Basement Membrane: (LM) Identified better using special stains such as PAS (Per-iodic acid Schiff) Silver impregation methods Invests capillaries incompletely, and is continuous with capsular BM

22. Juxta-glomerular apparatus JG cells of afferent arteriole, macula densa of DCT, Lacis cells of mesangium Principal source of renin

23. Tubules and interstitium Proximal tubules: Rich in mitochondria, microvilli, canaliculi and interdigitations - Major site for re-absorption of water, glucose, sodium, potassium, phosphate, proteins, amino acids. Vulnerable to vascular and toxic injury.

24. ... Histology of PCT

25. Proximal tubules: Abundant granular cytoplasm Distal tubules: Cuboidal cells

26. Loops of Henle, and Collecting Ducts

27. Interstitium: Scanty in the cortex and outer medulla More abundant in inner medulla