The functional and structural unit of the kidney is the nephron. Because the chief function of the kidney is to filter blood by regulating water concentration and soluble materials such as sodium and other salts, the nephron regulates the levels of electrolytes and controls the blood pH.
The nephron is often referred to as the basic unit of a kidney. Other functions of the nephron are to control blood pressure, normalize blood volume and expel waste from the body. Without the nephron, humans and animals would die soon after birth because they would not have a method of waste excretion.
There are hundreds of thousands of nephrons in each kidney, carrying deposits of waste from the Bowman’s capsule via the interstitial fluid. Here, urine is diluted or made more concentrated depending on water consumption levels and the concentration of salts. Kidneys regulate blood pH to prevent plasma from becoming either too acidic or too basic.
Another function is the production of hormones such as renin and erythropoietin. The kidney produces adequate amounts of plasma, standardizes osmopolarity and regulates key ions such as potassium, sodium and calcium. Other parts of the kidney include the renal column, minor calyx, renal pyramid, renal capsule, cortex and papilla of pyramid.