Final answer:
Homeostasis is maintained by a negative feedback loop involving a stimulus, sensor, control center, and effector, which acts to counteract changes in the body's internal environment.
Step-by-step explanation:
Maintenance of homeostasis in the body is achieved when an integrating center processes information regarding a change, and then sends a signal to a effector, which will react to produce a response in the opposite direction of the change. This process is known as a negative feedback loop. Homeostasis requires a stimulus, which is detected by a sensor, then relayed to a control center, which in turn prompts the effector to act. An effector can be a muscle that contracts or relaxes, or a gland that secretes hormones or other substances to restore equilibrium. It is primarily controlled by the nervous and endocrine systems in mammals.
For example, if body temperature rises, it's detected as a stimulus; the control center (the brain) signals to effectors (sweat glands and blood vessels) to initiate cooling processes. This type of regulation is vital to keep the body's physiological state within a narrow range compatible with life. Conditions like diabetes illustrate what happens when homeostatic mechanisms fail, leading to imbalance.