Which of the following is not considered a function of the kidneys?

Which of the following is not considered a function of the kidneys?

A. secretion

B. reabsorption

C. transport

D. filtration

Answer: A. secretion

Kidneys cleanse the blood from the products of the metabolism, the level of certain chemicals being adjusted, the level of fluid in the blood and a role in the synthesis of hormones that control blood pressure and the number of red blood cells. The main function of the kidneys includes filtration, reabsorption, and excretion. Based on the filtration process, the blood flows through the kidney for the elimination of waste products, water, and other unnecessary items with the help of the glomeruli. Re-absorption requires the process of absorption of some elements, water, glucose, and electrolytes amongst them, from the filtrate and returns it inside the bloodstream. Transport is defined as the capacity to move substances through the blood and parietal kidney tubules. Of the many functions of the kidneys, one that can be considered as secretion or the active process of including some substances in the kidney tubules from the blood is not among the most important.