Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Dee Unglaub Silverthorn, Ph.D.
HUMAN PHYSIOLOGYHUMAN PHYSIOLOGY
PowerPoint® Lecture Slide Presentation byDr. Howard D. Booth, Professor of Biology, Eastern Michigan University
AN INTEGRATED APPROACH
T H I R D E D I T I O N
Chapter 19, part AThe Kidneys
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
About this ChapterAbout this Chapter
• Anatomy of the excretory system
• How the kidney is organized
• How the nephron works to filter blood, recycle, secrete, and excrete
• How filtration is regulated
• Urination reflex
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
• Homeostatic regulation: ECF volume, osmolarity, ion & pH balance
• Excretion: Metabolic wastes & foreign molecules
• Regulating hormones & enzymes
Kidney Functions: OverviewKidney Functions: Overview
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Kidney Functions: OverviewKidney Functions: Overview
Figure 19-3: The excretion of a substance depends on the amount that was filtered, reabsorbed, and secreted
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Excretory System: Anatomy ReviewExcretory System: Anatomy Review
Figure 19-1: Anatomy Summary: The Urinary System
• Kidney
• Cortex
• Medulla
• Pelvis
• Nephrons
• Ureter
• Bladder
• Urethra
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Nephron Functions: OverviewNephron Functions: Overview
• Filtration, reabsorption, secretion & excretion
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Nephron Functions: OverviewNephron Functions: Overview
Figure 19-2: Filtration, reabsorption, secretion, and excretion
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Glomerulus & Bowman's Capsule: Blood FiltrationGlomerulus & Bowman's Capsule: Blood Filtration
• Capillaries
• Podocytes
• Mesanglial cells
• Bulk flow
• Solutes
• Water
• (Few proteins)
• (Not cells)
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Glomerulus & Bowman's Capsule: Blood FiltrationGlomerulus & Bowman's Capsule: Blood Filtration
Figure 19-4: Structure of the renal corpuscle
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Glomerular Flow Rate (GFR)Glomerular Flow Rate (GFR)
Figure 19-6: Filtration pressure in the renal corpuscle
• Capillary
• Hydrostatic pressure
• Colloidal
• Capsule pressure
• Back pressure
• Net Filtration p
• GFR 180L/day (about 1% is excreted)
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Glomerular Flow Rate (GFR)Glomerular Flow Rate (GFR)
Figure 19-5: The filtration fraction
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Regulation of GFRRegulation of GFR
• Autoregulation• Myogenic stretch• Tubuloglomerular feedback
• Macula densa• J G cells
• ANS-Sympathetic• Arteriole vasoconstriction• Hormones/paracrines
• Angiotensin II• Prostaglandins
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Regulation of GFRRegulation of GFR
Figure 19-9: The juxtaglomerular apparatus