You will be aware that if you drink large amounts of fluids, changes in urine output of water and electrolytes occur homeostatically to maintain the volume and composition of body fluids essentially constant.

This regulation can occur through changes in:

• the amounts filtered (GFR)
• the amounts reabsorbed

In this program we will provide data from a series of experiments in which changes in urine output occur as a result of changes in reabsorption at different parts of the nephron.

Additional Information

GFR (Glomerular Filtration Rate) Plasma is filtered through glomerular capillaries and the filtrate enters the glomerular (Bowman’s) capsule of the nephron. The rate at which this occurs is the GFR (ml/min).

Nephron The nephron is the functional unit of the kidney and comprises urinary tubules and small blood vessels associated with them. The tubular components are Bowman’s capsule, proximal convoluted tubule, loop of Henle, distal convoluted tubule. The glomerular filtrate is modified by reabsorption and secretion as it passes along the tubules. The fluid leaving the distal convoluted tubule is urine. Each kidney contains more than a million nephrons.