Tubular secretion is the transfer of materials from peritubular capillaries to the renal tubular lumen; it is the opposite process of reabsorption. Usually only a few substances are secreted, and are typically waste products. Urine is the substance leftover in the collecting duct following reabsorption and secretion.Click to see full answer. People also ask, what is the site of tubular secretion? Location of Tubular Secretion In humans, and other vertebrates, tubular secretion occurs in the kidneys, where the blood is filtered in specialized structures known as nephrons. These structures consist of a long tubule surrounded by extensive capillaries.Similarly, what is tubular secretion and where does it occur? amely filtration, reabsorption, secretion, and excretion. Tubular secretion occurs throughout the different parts of the nephron, from the proximal convoluted tubule to the collecting duct at the end of the nephron. Subsequently, one may also ask, how does tubular reabsorption occur? In renal physiology, reabsorption or tubular reabsorption is the process by which the nephron removes water and solutes from the tubular fluid (pre-urine) and returns them to the circulating blood. Thus, the glomerular filtrate becomes more concentrated, which is one of the steps in forming urine.Why is tubular reabsorption important?Tubular reabsorption is the process that moves solutes and water out of the filtrate and back into your bloodstream. This process is known as reabsorption, because this is the second time they have been absorbed; the first time being when they were absorbed into the bloodstream from the digestive tract after a meal.