The process by which excess substances are removed from the blood into the nephron is called?

The process described involves moving substances from the blood into the nephron, which is a key function of the kidneys. This specific process is known as secretion. During secretion, ions, drugs, and other substances such as hydrogen ions and potassium are actively transported from the bloodstream into the tubules of the nephron. This is an essential component of maintaining homeostasis by regulating the composition of body fluids and eliminating waste products.

Filtration, on the other hand, occurs at the glomerulus, where water and small solutes are filtered out of the blood into the Bowman's capsule, but it does not specifically refer to the removal of excess substances after filtration has occurred. Reabsorption is the process by which essential substances like glucose and certain ions are taken back into the bloodstream from the nephron after filtration. Excretion refers to the final elimination of waste products from the body in the form of urine. Each of these processes is crucial, yet they address different aspects of kidney function and fluid balance in the body.