urinary system

• URINARY SYSTEM - Elimination of waste products (Nitrogenous wastes, Toxins, Drugs)
• URINARY SYSTEM - Regulate aspects of homeostasis (Water balance, electrolytes, acid-base balance, blood pressure, RBC production, activation of Vitamin D)
• Organs of the Urinary System

  • Kidneys
  • Ureter
  • Urinary Bladder
  • Urethra
• REGIONS OF THE KIDNEY

  • RENAL CORTEX (OUTER REGION)
  • RENAL MEDULLA (INNER REGION)
  • RENAL PELVIS (INNER COLLECTING TUBE)
• RENAL CORTEX (OUTER REGION) - region of kidney that Stains darker than medulla
• RENAL MEDULLA (INNER REGION) - region of kidney that Contains 8-12 renal pyramids containing a renal lobe
• part of RENAL PELVIS (INNER COLLECTING TUBE)

  • Renal Pyramids
  • Renal Hilum
• Renal Pyramids - apical end contains renal papilla and minor calyx that eventually become one of three major calyces
• Renal pyramids are separated by structures called renal columns
• Renal Hilum - Where renal artery and vein are located
• Renal Hilum - The ureter exits the kidney from here
• RENAL VASCULATURE

  • RENAL ARTERY
  • RENAL VEIN
• RENAL ARTERY - Largest renal vasculature
• RENAL ARTERY - renal vasculature Divides into 2 segmental arteries at hilum
• RENAL ARTERY - renal vasculature that Supplies oxygenated blood from the heart to the kidneys
• 3 types of RENAL ARTERY

  • INTERLOBAR ARTERIES
  • ARCUATE ARTERIES
  • INTERLOBULAR ARTERIES
• INTERLOBAR ARTERIES - Branch from segmental arteries
• INTERLOBAR ARTERIES - Extend between renal pyramids towards corticomedullary junction
• ARCUATE ARTERIES - Branches from interlobar arteries
• INTERLOBULAR ARTERIES - Branches from arcuate arteries and Extend all the way to renal cortex
• In the cortex, afferent arterioles enter capillary clusters called glomeruli
• glomeruli - Where blood is filtered in the kidney & Drained by efferent arteries
• Efferent arterioles - Branch into peritubular capillaries and vasa recta
• RENAL VEIN - Carries deoxygenated blood from the kidney to the heart
• types of RENAL VEIN

  • Interlobar Vein
  • Arcuate Vein
  • Interlobular Vein
• From the large blood vessel branches into smaller and smaller vessels until the blood reaches our nephrons
• Glomerulus - Filters blood to form the initial filtrate
• nephrons - Blood flows out through the renal vein back to the heart
• Peritubular Capillaries - Reabsorb important substances back into the bloodstream
• Vasa recta - Help to maintain the concentration gradient in the medulla for water reabsorption and urine concentration
• VASA RECTA and PERITUBULAR CAPILLARIES - Both provide nutrients in their surrounding region
• VASA RECTA - They are straight venules and arterioles in the medullary region
• VASA RECTA - It provides oxygen and nutrients in the renal medulla
• VASA RECTA - They surround Henle’s loop
• PERITUBULAR CAPILLARIES - They are tiny blood vessels in the cortical region of the kidney
• PERITUBULAR CAPILLARIES - It provides oxygen and nutrients in the renal cortex
• PERITUBULAR CAPILLARIES - They lie to the distal and proximal convoluted tubules
• URINE FORMATION

  • Filtration, by which water and solutes in the blood leave the vascular space and enter the lumen of the nephron [site: glomerulus]
  • The filtration membrane of glomerulus or glomerular basement membrane allows water or small solutes to pass [blocks the blood cells or large proteins to pass through; remains in the bloodstream]
  • The filtrate or fluid that has passed through the membrane will flow from the glomerular capsule further into the nephron tubules
  • Reabsorption move water back into the bloodstream.
• URINE FORMATION

  • Secretion, by which substances move from epithelial cells of the tubules into the lumens, usually after uptake from the surrounding interstitium and capillaries.
  • The filtrate now contains wastes and other substances our body needs [ions, amino acids, small proteins, and glucose)
  • The secreted ions or waste ions with the remaining filtrate becomes urine; passes out the kidney through the renal pelvis -> ureter -> bladder -> urethra
• URINE FORMATION

  • Reabsorption, by which substances move from the tubular lumen across the epithelium into the interstitium and surrounding capillaries