22nd June 2023

Reabsorption and secretion

Compared to glomerular filtration, which is relatively non-selective, tubular reabsorption is highly selective, allowing for precise control of the body plasma composition. During reabsorption, solutes and water move from the renal tubule into the renal interstitium and then into the peritubular capillaries to rejoin the circulation.Reabsorption can be passive (i.e. diffusion of solutes down a concentration gradient) or active (i.e. transport of solutes against a concentration gradient).

Reabsorption can occur paracellularly (solutes are transported between cells) or transcellularly (solutes are transported through cells).