Final answer:
Secretion is the movement of substances out of the blood and into the tubule, aiding in kidney function and urine formation.
Step-by-step explanation:
Secretion refers to the movement of substances out of the blood and into the tubule.
For example, in the kidney, certain substances are secreted from the blood into the renal tubules, including urea, uric acid, and drugs.
This process plays a key role in kidney function and the formation of urine.
Learn more about Secretion