Final answer:
Active transport of a solute into the renal tubule, accompanied by osmosis and diffusion of other solutes, is termed active solute secretion, which is an essential part of the tubular secretion phase in urine formation.
Step-by-step explanation:
The active transport of a solute into the renal tubule, followed by osmosis and diffusion of other solutes into the tubule, is known as active solute secretion. This mechanism occurs during the tubular secretion phase of kidney function, where specific substances are moved from the blood into the renal tubule. In this process, substances like urea, NH3, creatinine, and various drugs are secreted into the tubule. Tubular secretion is an important step in the formation of urine as it helps to eliminate wastes and maintain acid-base balance.