RENAL PARENCHYMAL



Individual syndromes of altered renal function can be grouped according to the structural ele­ment of the kidney affected by the disorder. These elements include the major vessels, arteries, and veins of the kidney; the glomerulus; the renal tub­ules and interstitium; and the conduits for urine flow from the renal calyces through the urethra. Specific diseases involving each of the structures will be discussed in this chapter. In addition, cer­tain diseases and conditions of systemic origin may affect one or more of these renal structures and present with renal manifestations.

Glomerular disease rarely causes local symp­toms; it is more likely detected by the presence of either edema or hypertension, the cardiovascular complications of this disorder. Smoky or bloody urine may be evident. Disordered glomerular functioneither proteinuria consequent to an al­tered glomerular filtration barrier or a reduced glomerular filtration rate (GFR) secondary to al­tered glomerular ultrafiltration dynamicschar­acterizes these diseases. Tubulointerstitial dis­eases are usually asymptomatic until renal damage is far advanced. These disorders charac­teristically present as abnormalities of urine com­position, i.e., failure of urinary concentrating abil­ity, saltwasting, failure of urinary acidification, or failure of complete resorption of organic solutes such as glucose. A decrease in GFR is a late man ifestation of these diseases. Vascular disease of the kidney may be associated with flank or ab­dominal pain and causes alteration of both glo­merular and tubular function. Obstruction of the urinary drainage system usually causes altera­tions in patterns of urination (oliguria, anuria, nocturia] and may also present with localized pain. Both glomerular and tubular function are disrupted.