Glomerular Filtration Lab Report

Glomerular filtration is the physical method the kidney uses to sort what should be excreted from what should be kept in the bloodstream. In the first part of the process, a membrane called the filtrate membrane filters out red blood cells, large proteins, and other large plasma solutes. For example, albumin is filtered out at this point, with only a tiny amount remaining in the subsequent glomerular filtrate. Because the afferent arteriole to the glomerulus is much larger than its efferent arteriole, fluid gets slowed down here quite a bit. The fluid that escapes the glomerulus through the efferent arteriole eventually goes to the renal vein. The rest of the glomerular filtrate is absorbed by the glomerular capsule directly adjacent to the …show more content…
How is this possible? The answers are the counter current exchanger and multiplier. As the descending portion of the nephron loop is gaining solutes from the flow of glomerular filtrate entering it, the interstitial fluid it is encountering is hypertonic. At this point, the nephron loop’s membrane is permeable and since the interstitial fluid is hypertonic, some of the filtrate leaves the nephron loop and some of the solutes in the interstitial fluid cross the permeable membrane so that both fluids end up isotonic to each other. As the filtrate continues along, the ascending portion of the nephron loop is impermeable to water, so the majority of solutes are able to leave the ascending loop via diffusion into the surrounding medullary tissue instead of being redirected up to the cortex. At this point, the process starts over, as the increased solute in the interstitial tissue once again permeates into the descending loop, continuing the pattern of the interstitial tissue and glomerular filtrate being isotonic to each other. So, as a whole, the CCE and CCM allow solute to stay in the medullary interstitial fluid by loading solute in the descending potion of the nephron loop and unloading it as it passes through the ascending portion. In this way, the renal medulla is able to have a much higher osmolarity than the renal