Which of the following is a function of the endocrine system?

• A. Movement of bones
• B. Processing of waste
• C. Absorption of nutrients
• D. Production of hormones

Answer: (D)

The endocrine system regulates the body's activities through hormones. Glands like the pituitary, thyroid, pancreas, and adrenal glands release chemical messengers into the bloodstream that travel to target cells to control processes such as metabolism, growth, and reproduction. Because producing and releasing these hormones is exactly how the endocrine system communicates and coordinates bodily functions, that option is the best fit. The other options describe roles belonging to other systems: moving bones involves the skeletal and muscular systems; processing waste involves the excretory and digestive systems; absorbing nutrients happens mainly in the digestive system.