Which of the following is NOT a function of the digestive system?

Which of the following is NOT a function of the digestive system?

a. filtration.

b. compaction.

c. ingestion.

d. absorption.

e. mechanical processing.

Answer: a. filtration.

The digestive system plays a part of an organism in effectively and efficiently digesting food, assimilating the nutrients it contains, and excreting waste products. It involves ingestion, mechanical digestion, chemical digestion, absorption, and compaction i.e. taking in of food, physically breaking down of food through churning, using enzymes to breakdown food molecules, uptake of nutrients in the blood and making faeces. Of all these, filtration is not a key function that is under the digestive system. Filtration is best described as the process most related to the urinary system; the primary organ of the urinary system is the kidneys, which filter waste products from the blood. However, it should be noted that while the digestive system chooses to absorb certain nutrients, this selection is not an instance of filtration. The other options enumerated here (compaction, ingestion, absorption, mechanical processing) are other functions of the digestive system that also play a vital role in ensuring that food taken is broken down and nutrients made available to the body.