Question

multiple choice 1 point
a diagram of the digestive system is shown below.
mouth
esophagus
stomach
large intestine
small intestine
rectum

1. what is the main function of the digestive system?

a) to exchange oxygen and carbon dioxide gases within the body.
b) to break down food into nutrients that can be circulated throughout the body
c) to send signals from one part of the body to other parts of the body.
d) to protect the body against foreign substances, such as bacteria and viruses.

Explanation:

The digestive system's main role is digestion. It takes in food, breaks it down (through mechanical and chemical means) into smaller nutrient - rich components (like amino acids, simple sugars, and fatty acids). These nutrients are then absorbed (mostly in the small intestine) and circulated via the bloodstream to cells throughout the body for energy production, growth, and repair.

• Option A: Gas exchange (oxygen and carbon dioxide) is the function of the respiratory system.
• Option C: Sending signals is the function of the nervous system.
• Option D: Protecting against foreign substances is a function of the immune system.

Answer:

B. To break down food into nutrients that can be circulated throughout the body