PSL201Y1 Chapter 18: Chapter 18.docx
Document Summary
By regulating the plasma composition the kidneys ultimately control the volume and composition of all the body"s fluids. Secondary kidney functions include: secretion of hormones and enzymes, erythropoietin -stimulates erythrocyte production, renin - enzyme that converts angiotensinogen into angiotensin i, activation of vitamin d3, gluconeogenesis during periods of need. Three basic exchange processes of the renal nephrons are: glomerular filtration, reabsorption, secretion. Filtration is driven by starling forces (hydrostatic and osmotic pressure gradients). The filtrate resembles plasma except in lacking proteins present in plasma. Together these three layers form the glomerular membrane or filtration barrier. This membrane allows the bulk flow of protein-free fluid from the blood into the lumen of. The glomerular filtration pressure is the same thing as the net filtration rate and is due to the same starling forces: glomerular capillary hydrostatic pressure. The higher hydrostatic pressure is due to the high resistance of the efferent arteriole: bowman"s capsule oncotic pressure.
