Nephron Microanatomy The Renal Corpuscle PCT The Loop

Nephron Microanatomy The Renal Corpuscle PCT The Loop of Henle DCT Tubuloglomerular Feedback Collecting Tubules and Ducts Marieb: 25

Two Types of Nephrons Cortical (85%) Juxtamedullary (15%)

The Renal Corpuscle Makes Filtrate Afferent arteriole Glomerulus Efferent Arteriole Bowman’s Capsule

Bowman’s Capsule Parietal Layer Visceral Layers Capsular Space

Bowman’s Capsule Podocytes Filtration Slits

The Filtration Membrane Fenestrated Capillaries Basement Membrane Filtration slits in podocytes

Filtrate formation Depends on Pressure Afferent arteriole - high pressure - large Efferent Arteriole - small

Filtrate versus Tubular Fluid Tubular Absorption Tubular Secretion

Renal Tubule: Proximal Convoluted Tubule Cortical Polar epithelium Mitochondria Microvilli

Capillaries Allow Material to Return to Blood Peritubular Capillaries Low pressure, very porous

Renal Tubule: Loop of Henle*** Descending Limb -Aquaporins Ascending Limb -Mg++ recovery -Na. Cl leaves ***

Vasa Recta Return Material to Blood Vasa recta is associated with the Loops of Henle ***

Renal Tubule: Distal Convoluted Tubule Cortical Polar epithelium DCT has looped back to its afferent arteriole!

Is now tubular fluid here! Filtrate from here

Juxtaglomerular Apparatus Beginning of DCT Macula Densa (wall of DCT) Afferent arteriole Granule Cells

Collecting Tubules are found in the Cortex Last part of the Nephron Intercalated Cells A cells B cells Principal Cells

Collecting Ducts form Urine Run through medullary pyramid Variable amounts of H 2 O return to the blood

Juxtaglomerular Apparatus Allows each nephron to control its own flow rate

Net Filtration Pressure (NFP) Sum of all pressures that act at the renal corpuscle. Drives filtrate into the nephron. The amount and speed of filtrate/tubular fluid movement is proportional to NFP.

Net Filtration Pressure (NFP): Pressure Glomerular hydrostatic pressure (HPg) Capsular hydrostatic pressure (HPc)

Net Filtration Pressure (NFP): Osmotic Colloid osmotic pressure (OPg)

Intrinsic Control: Control at Kidney Level Nephron by nephron control Macula densa Measures [Na] [Cl]

Intrinsic Control: Tubuloglomerular Feedback [Na] [Cl] proportional to NFP Macula densa releases vasoconstrictive substance (ATP)

https: //www. youtube. com/watch? v=8 NPz. L BSBz. PI