Solvent drag

Solvent Drag

Solvent drag (pronunciation: /ˈsɒlvənt dræɡ/) is a phenomenon in physiology that refers to the movement of water and solutes across a cell membrane due to the bulk flow of water.

Etymology

The term "solvent drag" is derived from the English words "solvent", which refers to a substance that dissolves a solute, and "drag", which refers to the action of pulling something forcefully or with difficulty.

Definition

Solvent drag is a process that occurs during the absorption and secretion of fluids in the body. It is particularly important in the kidney where it contributes to the reabsorption of sodium and chloride ions from the glomerular filtrate.

Mechanism

The mechanism of solvent drag involves the movement of water across a semi-permeable membrane, such as the cell membrane, due to osmotic pressure. As water moves, it "drags" along with it various solutes, including ions, small organic molecules, and even larger particles such as proteins. This movement is driven by the concentration gradient of the solute, with solutes moving from areas of higher concentration to areas of lower concentration.

Related Terms

Osmosis: The process by which solvent molecules move from an area of lower solute concentration to an area of higher solute concentration through a semi-permeable membrane.
Diffusion: The process by which particles spread out from each other in a solution.
Active transport: The movement of ions or molecules across a cell membrane into a region of higher concentration, assisted by enzymes and requiring energy.