Explain the mechanism of extra-renal salt excretion with suitable examples.
Answers
Human Excretion
General function of the kidney
The kidney has evolved so as to enable humans to exist on land where water and salts must be conserved, wastes excreted in concentrated form, and the blood and the tissue fluids strictly regulated as to volume, chemical composition, and osmotic pressure. Under the drive of arterial pressure, water and salts are filtered from the blood through the capillaries of the glomerulus into the lumen, or passageway, of the nephron, and then most of the water and the substances that are essential to the body are reabsorbed into the blood. The remaining filtrate is drained off as urine. The kidneys, thus, help maintain a constant internal environment despite a wide range of changes in the external environment.