What term describes a cell or organ that responds to commands from a control center in negative feedback?

The term that describes a cell or organ that responds to commands from a control center in a negative feedback loop is an effector. Effectors are essential in maintaining homeostasis; they carry out the responses necessary to restore balance when a change is detected. For instance, if the body temperature rises, the effector (such as sweat glands) will initiate sweating to cool the body down, thereby negating the initial stimulus of increased temperature.

Understanding the role of effectors in negative feedback helps illustrate how the body regulates various physiological processes. They work in conjunction with receptors, which detect changes in the environment, and integrators (also known as control centers), which process this information and send commands to the effectors. In contrast, the term stimulus refers to the initial change that triggers the feedback response but does not describe the component that acts upon commands from the control center.