Final answer:
Reabsorption of glucose from the urinary filtrate into the blood is a tightly regulated process that occurs primarily in the proximal convoluted tubule of the kidneys, involving glucose transport proteins and based on the energy from sodium gradients.
Step-by-step explanation:
Transport of glucose from the urinary filtrate into the blood is called reabsorption, because the glucose is recovered from the primary urine and returned to the blood, reducing the amount lost in the urine. In the kidneys, this process mainly occurs in the proximal convoluted tubule (PCT). Glucose reabsorption involves glucose transport proteins (GLUTs) and is tightly regulated to prevent hyperglycemia and glycosuria. A symport mechanism uses the energy from the sodium gradient, created by sodium-potassium ATPases, to co-transport glucose against its concentration gradient back into the bloodstream.