Table of Contents

Introduction to the Kidney 1 Physiology of Body Fluids OBJECTIVES PHYSICOCHEMICAL PROPERTIES OF ELECTROLYTE SOLUTIONS Molarity and Equivalence Osmosis and Osmotic Pressure Osmolarity and Osmolality Tonicity Oncotic Pressure Specific Gravity VOLUMES OF BODY FLUID COMPARTMENTS COMPOSITION OF BODY FLUID COMPARTMENTS FLUID EXCHANGE BETWEEN BODY FLUID COMPARTMENTS Capillary Fluid Exchange Cellular Fluid Exchange SUMMARY KEY WORDS AND CONCEPTS SELF-STUDY PROBLEMS 2 Structure and Function of the Kidneys OBJECTIVES STRUCTURE OF THE KIDNEYS Gross Anatomy Ultrastructure of the Nephron Ultrastructure of the Renal Corpuscle Ultrastructure of the Juxtaglomerular Apparatus Innervation of the Kidneys SUMMARY KEY WORDS AND CONCEPTS SELF-STUDY PROBLEMS 3 Glomerular Filtration and Renal Blood Flow OBJECTIVES RENAL CLEARANCE Glomerular Filtration Rate GLOMERULAR FILTRATION Determinants of Ultrafiltrate Composition Dynamics of Ultrafiltration RENAL BLOOD FLOW REGULATION OF RENAL BLOODS FLOW AND GLOMERULAR FILTRATION RATE Sympathetic Nerves Angiotensin II Prostaglandins Nitric Oxide Endothelin Bradykinin Adenosine Natriuretic Peptides ATP Glucocorticoids Histamine Dopamine SUMMARY KEY WORDS AND CONCEPTS SELF-STUDY PROBLEMS 4 Renal Transport Mechanisms: NaCl and Water Transport Along the Nephron OBJECTIVES GENERAL PRINCIPLES OF MEMBRANE TRANSPORT GENERAL PRINCIPLES OF TRANSEPITHELIAL SOLUTE AND WATER TRANSPORT NaCl, SOLUTE, AND WATER REABSORPTION ALONG THE NEPHRON Proximal Tubule Henle's Loop Distal Tubule and Collecting Duct REGULATION OF NaCL AND WATER REABSORPTION SUMMARY KEY WORDS AND CONCEPTS SELF-STUDY PROBLEMS 5 Regulation of Body Fluid Osmolality: Regulation of Water Balance OBJECTIVES ANTIDIURETIC HORMONE Osmotic Control of ADH Secretion Hemodynamic Control of ADH Secretion ADH Actions on the Kidneys THIRST RENAL MECHANISMS FOR DILUTION AND CONCENTRATION OF THE URINE Medullary Interstitium Vasa Recta Function ASSESSMENT OF RENAL DILUTING AND CONCENTRATING ABILITY SUMMARY KEY WORDS AND CONCEPTS SELF-STUDY PROBLEMS 6 Regulation of Extracellular Fluid Volume and NaCl Balance OBJECTIVES CONCEPT OF EFFECTIVE CIRCULATING VOLUME VOLUME-SENSING SYSTEMS Vascular Low-Pressure Volume Sensors Vascular High-Pressure Volume Sensors Hepatic Sensors Central Nervous System Na+ Sensors Volume Sensor Signals Renal Sympathetic Nerves Renin-Angiotensin-Aldosterone System Natriuretic Peptides Antidiuretic Hormone CONTROL OF RENAL NaCL EXCRETION DURING EUVOLEMIA Mechanisms for Maintaining the Delivery of Na+ to the Distal Tubule Constant Regulation of Distal Tubule and Collecting Duct Na+ Reabsorption CONTROL OF Na+ EXCRETION WITH VOLUME EXPANSION CONTROL OF Na+ EXCRETION WITH VOLUME CONTRACTION EDEMA Alterations in Starling Forces The Role of the Kidneys SUMMARY KEY WORDS AND CONCEPTS SELF-STUDY PROBLEMS 7 Regulation of Potassium Balance OBJECTIVES OVERVIEW OF K+ HOMEOSTASIS REGULATION OF PLASMA [K+] Epinephrine Insulin Aldosterone ALTERATIONS OF PLASMA [K+] Acid-Base Balance Plasma Osmolality Cell Lysis Exercise K+ EXCRETION BY THE KIDNEYS CELLULAR MECHANISMS OF K+ SECRETION BY PRINCIPAL CELLS IN THE DISTAL TUBULE AND COLLECTING DUCT REGULATION OF K+ SECRETION BY THE DISTAL TUBULE AND COLLECTING DUCT Plasma [K+] Aldosterone Antidiuretic Hormone FACTORS THAT PERTURB K+ EXCRETION Flow of Tubular Fluid Acid-Base Balance Glucocorticoids SUMMARY KEY WORDS AND CONCEPTS SELF-STUDY PROBLEMS 8 Regulation of Acid-Base Balance OBJECTIVES THE HCO3- BUFFER SYSTEM OVERVIEW OF ACID-BASE BALANCE NET ACID EXCRETION BY THE KIDNEYS HCO3- REABSORPTION ALONG THE NEPHRON REGULATION OF H+ SECRETION Formation of New HCO3- RESPONSE TO ACID-BASE DISORDERS Extracellular and Intracellular Buffers Respiratory Compensation Renal Compensation SIMPLE ACID-BASE DISORDERS Metabolic Acidosis Metabolic Alkalosis Respiratory Acidosis Respiratory Alkalosis ANALYSIS OF ACID-BASE DISORDERS SUMMARY KEY WORDS AND CONCEPTS SELF-STUDY PROBLEMS 9 Regulation of Calcium and Phosphate Homeostasis OBJECTIVES CALCIUM Overview of Ca++ Homeostasis Ca++ Transport along the Nephron Regulation of Urinary Ca++ Excretion Calcium-Sensing Receptor PHOSPHATE Overview of Pi Homeostasis Pi Transport along the Nephron Regulation of Urinary Pi Excretion INTEGRATIVE REVIEW OF PARATHYROID HORMONE, CALCITRIOL, AND CALCITONIN ON Ca++ AND PI HOMEOSTASIS SUMMARY KEY WORDS AND CONCEPTS SELF-STUDY PROBLEMS 10 Physiology of Diuretic Action OBJECTIVES GENERAL PRINCIPLES OF DIURETIC ACTION Sites of Action of Diuretics Response of Other Nephron Segments Adequate Delivery of Diuretics to Their Site of Action Volume of the Extracellular Fluid DIURETIC BRAKING PHENOMENON MECHANISMS OF ACTION OF DIURETICS Osmotic Diuretics Carbonic Anhydrase Inhibitors Loop Diuretics Thiazide Diuretics K+-Sparing Diuretics Aquaretics EFFECT OF DIURETICS ON THE EXCRETION OF WATER AND OTHER SOLUTES Solute-Free Water K+ Excretion HCO3- Excretion Ca++ and Pi Excretion SUMMARY KEY WORDS AND CONCEPTS SELF-STUDY PROBLEMS Additional Reading APPENDIX A Integrative Case Studies APPENDIX B Normal Laboratory Values APPENDIX C Nephron Function APPENDIX D Answers to Self-Study Problems APPENDIX E Answers to Integrative Case Studies APPENDIX F Review Examination Index

About the Author

Bruce Koeppen, founding dean of the Frank H. Netter MD School of Medicine at Quinnipiac, recently received two prestigious awards: honored by the Patient is U Foundation - a nonprofit that aims to encourage human communication in health care and support both patients and providers and the (LCME) Liaison Committee on Medical Education's 2019 Distinguished Service Award. Bruce Stanton received the Unsung Hero Award in 2019 from the Cystic Fibrosis Foundation. He played a key role in the development of Vertex modulators and is connected with sparking the creation of a Patient Registry which has had an enormous impact on the length and quality of lives in CF patients.