PATHOLOGY: DISEASES OF THE KIDNEY PART1 Components of the normal kidney • Blood vessels • Glomeruli o Components of the Glomerulus Endothelial cells- line the glomerular capillaries GBM- composed of collagen, laminin, proteoglycan, fibronectin; effective filtration barrier • Lamina rara interna • Lamina densa • Lamina rara externa Visceral epithelial cells (podocytes) • Foot processes- enclose/ wrap around capillaries • Filtration slits- b/w foot processes • Slit diaphragm- made up of CHONs Mesangial cells- contractile, phagocytic, secrete mediators, capable of proliferation • Tubules • Interstitium Features of the Filtration Barrier • Highly permeable to water and solutes • Impermeable to CHONs o Size of CHONs o Charge of CHONs o Slit diaphragm AZOTEMIA UREMIA • Biochemical abnormality • Elevated BUN • Elevated creatinine o d/t decreased GFR: pre-renal (CHF, shock) post-renal (obstruction) • Azotemia + clinical s/sxs • Failure of renal fxn • Metab and endo d/o • 2ndary involvement of GIT, peripheral NS, CVS Clinical presentation s of Renal Dses 1. Acut e nephrit ic syndr ome- acu te onset of gros s hematu ria, mild to moderate proteinuria, HPN 2. Nephr otic syndr ome- marke d hematur ia, hyperlip idemia 3. Asymptomat ic hema turia / prot einur ia 4. ARF- ac ute azot emia asso c with olig uria/a nuria 5. CRF- prolonged ur emia, END STAGE of all ren al dse 6. Manifestations of renal tubular defects- polyuria, nocturia, e lectrolyte imbalance 7. UTI - pyu ria, bacteu ria 8. Nephr olithiasis- r enal c olic, h ematu ria 9. Urina ry tract ob struc tion an d renal tumors NEPHRITIC NEPHROTIC • Hematuria • Mild to moderate proteinuria • HPN • Heavy proteinuria • Hypoalbuminemia • Severe edema • Hyperlipidemia • Lipiduria Stages of CRF STAGE GFR CHARACTERISTIC Diminished renal reserve 50% Susceptib le to developin g azotemia Re nal in suff ic ie n cy 20-50% Az ote mia a ss oc wit h an emia and HPN Renal failure <20- 25% Edema, metab acidosis, uremia End-stage renal dse <5% Kidney doesn’t become f xnal at all
