What is the process called when solutes move from the filtrate back to the blood?

The process by which solutes move from the filtrate back to the blood is known as reabsorption. During this process, substances that the body needs, such as glucose, amino acids, and certain ions, are selectively transported from the tubular fluid (filtrate) in the nephron back into the bloodstream. This is crucial for maintaining homeostasis, as it allows the body to reclaim essential nutrients and maintain electrolyte balance.

Reabsorption occurs primarily in the proximal convoluted tubule of the nephron but also takes place in other parts, such as the loop of Henle and the collecting duct, depending on the type of solute and the body's needs. Through various mechanisms, including active transport, facilitated diffusion, and passive diffusion, the nephron can effectively regulate what is reabsorbed based on the body's current requirements.

Other processes mentioned, such as filtration, refer to the initial movement of water and solutes from the blood into the nephron, while secretion involves the transfer of substances from the blood into the filtrate, which are often waste products that the body needs to eliminate. Excretion refers to the final elimination of waste products from the body through urine. This distinction highlights the specific role of reabsorption as a means of