Final answer:
The Glomerular Filtration Rate (GFR) measures renal function by determining the volume of blood filtered into the Bowman's capsule per minute, which is crucial for monitoring kidney excretory performance and safe medication dosing.
Step-by-step explanation:
The Glomerular Filtration Rate (GFR) is a laboratory assessment test that is used to measure renal function. It represents the amount of blood filtered by the glomerulus into the Bowman's capsule per minute. The GFR is an essential tool in assessing the kidney's excretory function, which is crucial for managing drug dosages and monitoring for potential toxic accumulations of substances normally cleared by the kidneys. High blood pressure in the glomerulus, due to specialized membranes in the afferent arteriole, facilitates the passage of most solutes except larger macromolecules like proteins. The estimation of GFR is usually done by measuring the concentration of creatinine in the blood, as it is produced naturally by muscle metabolism and is filtered but not reabsorbed or only minimally secreted by the kidneys.