Which term means the human body's maintenance of stability amidst changing conditions?

• A. Metabolism
• B. Homeostasis
• C. Equilibrium
• D. Homeostatic imbalance

Answer: (B)

The main idea is keeping the body's internal environment stable while the outside conditions change. This stability, or steady state, is called homeostasis. It relies on sensors that detect deviations, a control center that compares what is happening to the desired value, and effectors that bring about responses to restore balance. Often this works through negative feedback, where a change triggers actions that counteract it and push the system back toward a set point. For example, if body temperature rises, mechanisms like sweating and vasodilation help cool the body; if it falls, shivering and vasoconstriction help conserve or generate heat. Glucose levels are kept steady by insulin and glucagon, maintaining energy supply for cells.

Metabolism describes the chemical processes the body uses to convert energy, not the ongoing regulation of internal stability. Equilibrium is a general idea of balance and can apply to many contexts, but it doesn’t capture the active regulatory mechanism maintaining stability in living systems. A homeostatic imbalance is a disruption to this stable state, not the normal maintenance itself.