If a non-diabetic person releases glucose in urine, it may be due to a defect in selective reabsorption. Selective reabsorption is the process by which the nutrients and electrolytes which are required by the body are reabsorbed from the renal tubules. If there is a defect in this process, the reabsorption of glucose will be affected. Hence, there will be excretion of glucose in urine.

Ultrafiltration is the process by which the capillaries present in the Bowman's capsule filter the fluid which enters the renal tubules.

Tubular secretion is the process by which the fluid to be excreted out is secreted back in the renal tubules after absorption of essential substances.

Micturition is the act of urination.