Which system maintains homeostasis by coordinating metabolic processes via hormones?

• A. Endocrine System
• B. Digestive System
• C. Immune System
• D. Muscular System

Answer: (A)

The endocrine system coordinates metabolic processes through hormones to maintain internal balance. Glands release hormones into the bloodstream, and these chemical messengers travel to various organs to regulate energy use, nutrient storage, growth, and responses to stress. For example, insulin and glucagon work together to keep blood glucose within a narrow range, while thyroid hormones set the body's overall metabolic rate. This system relies on feedback loops to keep everything steady: when a value deviates, the appropriate hormone adjusts activity to restore balance.

The digestive system mainly handles breaking down food and absorbing nutrients, the immune system defends against pathogens, and the muscular system enables movement. While those systems play essential roles in health, they do not coordinate metabolic processes throughout the body via hormones in the way the endocrine system does.