Glomerulonephritis: Nursing

Glomerulonephritis refers to inflammation of the glomeruli. It can be primary when the disease starts in the glomeruli, or secondary, when the glomeruli are affected by systemic disease. It can also be acute, when symptoms develop suddenly and resolve with treatment; or it can be chronic if acute disease is not treated, or when the disease process develops slowly, leading to irreversible failure of the kidneys.

First, let’s quickly review some kidney physiology! Remember that the nephron is the functional unit of the kidney, and its role is to filter waste products and water from the blood. Each nephron is made up of a renal corpuscle and a set of renal tubules, which are, in order: the proximal convoluted tubule, loop of Henle, distal convoluted tubule and finally, collecting ducts which drain urine into the renal papillae and eventually empty into the renal pelvis.

The renal corpuscle is made up of the glomerulus, which is a bundle of capillary loops, and Bowman’s capsule, which surrounds the glomerulus. Now, blood enters the glomerulus through the afferent arteriole, then moves inside the glomerulus, where glomerular filtration occurs. Then, the remaining blood exits the glomerulus through the efferent arteriole. Now, the glomerular capillary wall is a semi-permeable membrane with three layers: the endothelium, which is the inner layer; the basement membrane; and the epithelium, which is the outermost layer.

For filtration to occur, the endothelial and epithelial cells that line the capillary wall are separated by small pores that filter water and small particles from the blood and into the Bowman capsule. Only small particles are filtered from the blood and never proteins, since they are larger molecules. Also, normally, there aren’t any red blood cells in the urine. For glomerular filtration to occur, the hydrostatic pressure created by the blood pressure needs to be greater than opposing forces, such as the tubular filtrate and oncotic pressure, which is the pressure of proteins. The final product of filtration is called filtrate or primary urine, which will flow through the Bowman capsule into the proximal convoluted tubule.