Final answer:
The renal process where molecules are selectively reabsorbed from the tubule lumen into the blood through the peritubular capillaries and the vasa recta is called tubular reabsorption. It primarily occurs in the proximal convoluted tubule and the loop of Henle, enabling the conservation of water, glucose, and amino acids.
Step-by-step explanation:
The process during which molecules are selectively removed from the tubule lumen, moved into the interstitial space, and then taken up by the peritubular capillaries and the vasa recta is known as tubular reabsorption. This is an integral part of kidney function and physiology. During tubular reabsorption, substances such as water, glucose, and amino acids are reclaimed from the filtrate and returned to the blood. About two-thirds of the filtered salts and water and all of the filtered organic solutes are reabsorbed mainly in the proximal convoluted tubule and the loop of Henle.
On the other hand, tubular secretion refers to the process where additional solutes and wastes that were not previously reabsorbed or that need to be eliminated from the body are actively transported into the renal tubules. Reabsorption and secretion together ensure that essential substances are conserved while waste products are appropriately excreted in the urine.