Chemical pathology of the kidney by Z Ngwira-unza

Description

This comprehensive lecture by Z Ngwira explores the chemical pathology of the kidney, detailing its normal physiology and the diagnostic tests used to assess its function. It begins with the kidney's role in maintaining extracellular fluid constancy through filtration, reabsorption, and secretion, alongside its endocrine functions. The structure and function of the nephron are explained, covering glomerular filtration and the specific roles of the proximal tubule, loop of Henle, distal convoluted tubule, and collecting ducts. Key disorders such as Fanconi syndrome, diabetes insipidus, and SIADH are highlighted in relation to tubular dysfunction. The core of the presentation focuses on renal function tests, distinguishing between assessments of glomerular and tubular function. It evaluates traditional markers like serum creatinine and urea, clarifies their limitations, and explains the measurement and estimation of Glomerular Filtration Rate (GFR) through creatinine clearance and formulas like Cockcroft-Gault and MDRD. More accurate methods involving radio-isotope tracers such as inulin and Cr-51 EDTA are also discussed. Tubular function tests, including urinary sodium concentration and acidification tests, are covered. The analysis of urine protein, from microalbuminuria indicating early dysfunction to significant proteinuria in nephrotic syndrome, is explained, along with specific markers like cystatin C and ß2-microglobulin. The document concludes with an overview of acute and chronic renal failure, their aetiologies, classifications, and biochemical features. This resource is vital for medical and biomedical science students in Zambia, providing essential knowledge for interpreting renal biochemistry, diagnosing kidney disorders, and understanding the progression of renal disease. Use this guide to enhance your clinical acumen in nephrology and laboratory medicine.