Question

Which of the following processes of urine formation take place along the renal tubules and collecting duct?

• A. Ultrafiltration and tubular reabsorption
• B. Tubular reabsorption and secretion
• C. Ultrafiltration and tubular secretion
• D. None of the above

Answer 1

The correct option is B Tubular reabsorption and secretion

Urine formation is a multi step process that includes many processes like ultrafiltration, tubular reabsorption and tubular secretion.
Ultra-filtration is the fine filtering of blood through the filtration membrane and it occurs in the glomerulus.
Nearly 99 percent of the filtrate formed by the kidney is reabsorbed through the tubules, this process is called tubular reabsorption.
During urine formation, the tubular cells secrete substances like hydrogen ions, potassium ions and ammonia into the filtrate. This process is called tubular secretion.