Which of the following systems is responsible for releasing hormones that regulate body activities?

• A. Nervous
• B. Endocrine
• C. Skeletal
• D. Reproductive

Answer: (B)

Releasing hormones that regulate body activities is the function of the endocrine system. Glands such as the pituitary, thyroid, adrenal, and pancreas produce hormones that are released into the bloodstream and travel to distant targets to control processes like metabolism, growth, development, and homeostasis. This hormonal signaling tends to be slower to start but longer lasting than the nervous system’s rapid, electricity-based signaling via neurotransmitters. The skeletal system isn’t about hormone release for regulating activities, and while reproductive organs produce hormones, their primary role isn’t the broad, body-wide hormonal regulation described here.