Volume+Homeostasis

Objectives
>* Description should be in terms of sensors, effectors
 * Describe how the kidney balances the body's water and salt content
 * Describe how various electrolyte salts are distributed throughout the body
 * Describe how sodium influences the extracellular volume
 * Describe how various parts of the nephron handle salt
 * Describe the various feedback mechanisms the body uses to control salt level
 * Define the concept of 'Effective Circulating Volume'

body is 60% fluids 2/3 of fluids is intracellular 3/4 of ECF is interstitial
 * kidney is major effector

Body Composition for a 70 kg person Sensor Effector Effect on GFR Effect on H2O Resorp. Effect on Na+ Resorp.
 * Compartment || Fraction || Volume || Percent Weight ||
 * Total Body Fluid || 3/5 TBW || 42L || 60% ||
 * Intracellular Fluid || 2/3 TBF || 28 || 40% ||
 * Extracellular Fluid || 1/3 TBF || 14 || 20% ||
 * ECF-Interstitial || 3/4 ECF || 10.5 || 15% ||
 * ECF-Plasma || 1/4 ECF || 3.5L || 5% ||
 * Sensor || Effector || Effect on GFR || Effect on H2O Resorp || Effect on Na+ Resorp. ||
 * JGA || RAA, Sympathetic || Decrease || Increase || Increase ||
 * Carotid Sinus, Aortic Arch || ADH, Sympathetic || Decrease || Increase || Increase ||
 * Right Atrium || ANF || Increase || Decrease in CD || Decrease in CD ||

Atrial Natriuretic Factor Aldosterone Renin RAA System Anti-Diuretic Hormone Sympathetic Agonists Macula Densa


 * 0.9%wt saline stays in ECF