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  <head>
    <title>017-01 Foundations</title>
    <ownerName>Integrated Medical Foundations</ownerName>
  </head>
  <body>
    <outline text="Glomerular filtration, tubular transport, concentration, and clearance">
      <outline text="Renal roles and endocrine functions">
        <outline text="Filter plasma, reabsorb, secrete, regulate electrolytes"/>
        <outline text="Acidity, pressure, erythropoietin, vitamin D"/>
        <outline text="Erythropoietin follows hypoxia-inducible signalling">
          <outline text="Chronic disease gives hypoproliferative anaemia"/>
        </outline>
        <outline text="Proximal cells activate vitamin D">
          <outline text="Parathyroid hormone and low phosphate stimulate it"/>
          <outline text="Failure brings hyperparathyroidism and bone disease"/>
        </outline>
      </outline>
      <outline text="Circulation and nephron organisation">
        <outline text="Afferent arteriole supplies each glomerular tuft"/>
        <outline text="Blood leaves through an efferent arteriole">
          <outline text="Peritubular capillaries surround cortical tubules"/>
          <outline text="Vasa recta descend into the medulla"/>
        </outline>
        <outline text="Capsule, proximal, loop, distal, collecting duct"/>
        <outline text="Juxtamedullary long loops allow urine concentration"/>
        <outline text="Cortex takes most flow, medulla little">
          <outline text="Sodium transport drives medullary oxygen demand"/>
        </outline>
      </outline>
      <outline text="Glomerular filtration barrier">
        <outline text="Fenestrated endothelium, basement membrane, podocyte slits"/>
        <outline text="Size, shape, and charge govern passage"/>
        <outline text="Albumin restricted, small amounts reclaimed proximally"/>
        <outline text="Injury gives haematuria, proteinuria, filtration loss">
          <outline text="Dysmorphic cells and casts mean glomerular bleeding"/>
          <outline text="Nephrotic: oedema, hypoalbuminaemia, lipids, thrombosis"/>
          <outline text="Inflammatory: haematuria, hypertension, low filtration"/>
        </outline>
      </outline>
      <outline text="Filtration pressure and autoregulation">
        <outline text="Glomerular hydrostatic pressure favours filtration"/>
        <outline text="Bowman&#x27;s and plasma oncotic pressures oppose it"/>
        <outline text="Rate equals net pressure times filtration coefficient">
          <outline text="Coefficient reflects permeability and surface area"/>
        </outline>
        <outline text="Moderate efferent constriction raises glomerular pressure">
          <outline text="Severe constriction lowers flow and filtration"/>
        </outline>
        <outline text="Myogenic response constricts stretched afferent muscle"/>
        <outline text="Macula densa senses sodium chloride delivery">
          <outline text="Delivery sets afferent tone and renin release"/>
        </outline>
      </outline>
      <outline text="Proximal tubule">
        <outline text="Reclaims most sodium, water, bicarbonate, phosphate"/>
        <outline text="Nearly all glucose and amino acids normally"/>
        <outline text="Sodium-potassium pump powers apical transport">
          <outline text="Water follows solute, reabsorption is iso-osmotic"/>
        </outline>
        <outline text="Bicarbonate reclaimed, no new bicarbonate made"/>
        <outline text="Transport maximum exceeded gives osmotic diuresis"/>
        <outline text="Secretes organic acids and bases, including drugs"/>
        <outline text="Injury: bicarbonate, phosphate, glucose, amino acids"/>
      </outline>
      <outline text="Loop and countercurrent system">
        <outline text="Thin descending limb concentrates tubular fluid"/>
        <outline text="Thick ascending limb moves sodium, potassium, chloride">
          <outline text="Water impermeable, so tubular fluid is diluted"/>
        </outline>
        <outline text="Opposing flow multiplies a small transverse gradient"/>
        <outline text="Urea recycling adds to the inner medulla"/>
        <outline text="Vasa recta supply tissue and limit washout"/>
      </outline>
      <outline text="Distal nephron and collecting duct">
        <outline text="Early distal tubule takes sodium and chloride"/>
        <outline text="Principal cells reabsorb sodium, secrete potassium">
          <outline text="Aldosterone raises channel and pump activity"/>
        </outline>
        <outline text="Antidiuretic hormone inserts aquaporin two channels">
          <outline text="Without it, dilute urine is excreted"/>
        </outline>
        <outline text="Alpha cells secrete acid, beta cells bicarbonate"/>
        <outline text="Distal acid and ammonium make new bicarbonate"/>
      </outline>
      <outline text="Clearance and filtration markers">
        <outline text="Virtual plasma volume cleared per unit time"/>
        <outline text="Equals filtration for an unhandled filtered marker">
          <outline text="Inulin approximates the ideal experimentally"/>
          <outline text="Creatinine is filtered and partly secreted"/>
        </outline>
        <outline text="Small creatinine rise can mean large filtration loss"/>
        <outline text="Acute change defeats steady-state equations"/>
        <outline text="Filtration fraction is filtration over plasma flow"/>
        <outline text="Fractional excretion shifts with diuretics and illness"/>
      </outline>
      <outline text="Urine testing and sediment">
        <outline text="Dipstick: pH, blood, protein, glucose, nitrite">
          <outline text="False positives and negatives both occur"/>
        </outline>
        <outline text="Microscopy: cells, casts, crystals, organisms">
          <outline text="Hyaline casts can occur normally"/>
          <outline text="Red-cell casts support glomerulonephritis"/>
          <outline text="Muddy granular casts support tubular injury"/>
        </outline>
        <outline text="Albumin and protein ratios adjust for concentration"/>
      </outline>
      <outline text="Diuretic sites as physiology probes">
        <outline text="Carbonic-anhydrase inhibitors cut proximal reclamation"/>
        <outline text="Loop diuretics weaken the medullary gradient">
          <outline text="Calcium and magnesium excretion rise"/>
        </outline>
        <outline text="Thiazides reduce distal sodium chloride uptake">
          <outline text="Calcium excretion falls"/>
        </outline>
      </outline>
    </outline>
  </body>
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