COURSE OBJECTIVES

The objectives of this course are to have students master the following topics and to apply this knowledge to problems and case studies relevant to clinical physiology.

INTRODUCTION

• Roles of the Kidney
• Typical composition of plasma and urine
• Urine formation rate

FUNCTIONAL ANATOMY OF THE RENAL SYSTEM

• Role of the ureter, bladder, urethra
• Components of the nephron

RENAL BLOOD FLOW

• Components of the renal circulation
• Rate and distribution of renal blood flow
• Roles
• Control of blood flow:
• Nervous system (essential?)
• Pressure; autoregulation
• Interaction of nervous and autoregulation

GLOMERULAR FILTRATION

• Glomerular filtrate composition
• Mechanism; hydrostatic and osmotic pressures; role of afferent and efferent arterioles
• Glomerular filtration rate; autoregulation of GFR

PROXIMAL TUBULE TRANSPORT

• Role; reabsorption and secretion; transcellular and paracellular transport
• Primary active transport; Na-K-ATPase pump; Na reabsorption
• Secondary active transport; mechanism, glucose, amino acids, etc.
• Passive reabsorption; mechanism, chloride, potassium, urea
• Water reabsorption; forces and consequences for solute transport
• Active secretion
• Rate and composition of fluid leaving the proximal tubule
• Tubular transport maximum; glucosuria

CLEARANCE

• Formula
• Interpretation; relation to filtration and tubular transport
• Significance of creatinine/inulin and PAH clearance

RENAL WATER EXCRETION

• Functional anatomy of cortical and juxtamedullary nephrons
• Permeability and transport in the Loop of Henle and initial distal tubule
• thin descending limb, thin ascending limb, thick ascending limb
• Osmolar concentration in the renal medulla; countercurrent multiplication
• Role of urea
• Role of the vasa recta; countercurrent exchange
• Volume and composition of fluid leaving the Loop of Henle and initial distal tubule
• Water transport and permeability of the later distal tubule and collecting duct

RENAL WATER REGULATION

• ADH synthesis and release
• ADH action
• Control of ADH release and mechanisms
• Plasma osmolality and hypothalamic osmoreceptors
• Blood volume and low pressure baroreceptors
• Systemic arterial pressure and high pressure baroreceptors
• Other influences
• Osmolality of urine and rate of urine excretion
• Defense of body osmolar homeostasis

RENAL ELECTROLYTE TRANSPORT

• Sodium transport: proximal tubule, Loop of Henle, distal tubule and collecting ducts
• Chloride transport: proximal tubule, Loop of Henle, distal tubule and collecting ducts
• Potassium transport: proximal tubule, Loop of Henle, distal tubule and collecting ducts

RENAL ELECTROLYTE REGULATION

• Renin: synthesis and release; control; actions
• Angiotensin: synthesis and release, control; actions
• Aldosterone: synthesis and release; control; actions
• Atrial Natriuretic Peptide (ANP): synthesis and release; control; actions
• Urodilatin
• Summary of control
• Defense of extracellular Na and K composition

EXTRACELLULAR VOLUME REGULATION

• Sodium and extracellular volume
• Role of ADH, Renin-Angiotensin-Aldosterone system, ANP
• Defense of body extracellular volume

ACID-BASE BALANCE

• Introduction: normal pH values; acidosis, alkalosis vs. acidemia, alkalemia; pathophysiology
• Forms and Sources of H+: acid, base definition, metabolic sources, buffers, bicarbonate-CO2 system
• Disturbances of Acid-Base Balance
• Defenses Against pH Disturbance: buffers, respiratory compensation, renal compensation
• Evaluation of Acid-Base Status
• Diagnosis from Blood Values