What describes a functional grouping of organs?

The term that describes a functional grouping of organs is "system." In anatomy and physiology, a system is a collection of organs that work together to perform specific functions necessary to maintain homeostasis and support the life of the organism. For example, the circulatory system includes the heart, blood vessels, and blood, all functioning collaboratively to transport nutrients and oxygen throughout the body.

Understanding that a system represents a higher level of organization than tissues and cells is essential. Tissues are groups of similar cells that perform dedicated functions, while an organ consists of multiple tissue types working together. In contrast, structures are more general and can refer to any physical part of the body, which does not specifically convey the idea of functional collaboration. Thus, the correct term for a grouping of organs that work in unison is "system."