What are organs made of?

Organs are complex structures composed of specialized tissues that perform specific functions essential for the body's operation. Each type of tissue contributes to the overall task of the organ, working in harmony to enable processes such as digestion, circulation, and respiration. For instance, an organ like the heart includes muscular tissue for pumping blood, connective tissue for structure, and nervous tissue for regulation.

In contrast, single cells typically form tissues, rather than organs themselves. While fibrous tissues do play a role in some organs, they alone do not constitute an organ's composition. Fluid and cartilage may be components found within certain organs, such as cartilage in joints or fluid in the circulatory system, but they do not encompass the entirety of what makes up an organ. Therefore, the most accurate description of what organs are composed of is specialized tissues designed for specific functions.