Urinary system outflow obstruction and urinary system tumors
Urinary system - CBOhistologie.lf3.cuni.cz/histologie/materialy/doc/urinary system.pdf · •...
Transcript of Urinary system - CBOhistologie.lf3.cuni.cz/histologie/materialy/doc/urinary system.pdf · •...
Module A
Urinary System
Martin ŠpačekHistology and Embryology
• Pictures from:• Junqueira et al.: Basic histology• Rarey, Romrell: Clinical human embryology• Sadler: Langman’s medical embryology• Young, Heath: Wheather’s functional histology
Development of the Urinary System
• Development of the kidney– Pronephros– Mesonephros– Metanephros
• Development of excretory passages
Mesonephros
• At the end of the 4th week• Functional for a short time• Renal corpuscle
– glomerulus– Bowman’s capsule
• Tubules enter collecting duct –mesonephric or Wolffian duct
Metanephros• Permanent kidney• Development begins in the 5th week• Ureteric bud (an outgrowth of the mesonefric duct)
• Metanephric blastema
Metanephros• Ureteric bud → collecting tubules,
calyces, renal pelvis, ureter• Metanephric blastema → nephrons
Position of the Kidney• Ascent of the kidney
– initially located in the pelvic region– later more cranial position in the abdomen
Horseshoe kidney
Urinary BladderDevelops from the upper and largest part of the urogenital sinusContinuous with the allantois, but the lumen obliterates → urachus (median umbilical ligament)
Kidney
• Nephrons• Collecting tubules
& ducts• Juxtaglomerular
apparatus• Blood supply• Intersticium
Nephron
• Renal corpuscle– Glomerulus– Bowman’s capsule
• Proximal tubule• Henle’s loope• Distal tubule
Renal Corpuscle• Bowman’s capsule
– parietal layer (simple squamous epitelium)– visceral layer (podocytes with pedicels)
Renal Corpuscle• Mesangial cells
– synthesize the extracellular matrix and collagen– macrophages (?)
Proximal Tubule
• Simple cuboidalepithelium– brush border– basolateral labyrinth– abundant
mitochondria• Reabsorption of NaCl
and water (80-95%)
Henle’s loope
• Squamous simple epithelium– ascending limb is
impermeable to water• Juxtamedullary
nephrons have long HL
Distal Tubule• Simple cuboidal
epithelium– cells are smaller than
those of the proximal tubule
– no brush border– basolateral labyrinth
• Absorption of sodium, secretion of potassium
• Macula densa – modified segment– chemoreceptors
Collecting Tubules & Ducts• Collecting tubules
– simple cuboidalepithelium
• Papillary ducts– simple columnar
epithelium• ADH-dependent
water reabsorption
Juxtaglomerular Apparatus
• Macula densa of the distal tubule– sensitive to changes in NaCl concentration
• Extraglomerular mesangial cells (laciscells)
• Juxtaglomerular cells of the afferent arteriole– produce renin
Blood supply
• renal artery• interlobar arteries• arcuate arteries• interlobular arteries• afferent arterioles• efferent arterioles• peritubular capillary
network or vasa recta
Renal Intersticium
• Intersticial cells in the spaces between tubules and vessels
• Non-cellular elements• proteoglycans, glycoproteins, interstitial fluid
Excretory passages
• Mucosa (tunica mucosa)– transitional epithelium– lamina propria mucosae (connective
tissue)• Smooth muscle (tunica muscularis)• Adventitia (tunica adventitia)
Urinary bladder
• Mucosa folded• Smooth muscle layer
– mixture of randomly arranged fibers (m. detrusor)
– at the neck the fibers form a three layer sphincter (inner longitudinal, middle circular, outer longitudinal)