Interstitium

Part of speech: noun

Pronunciation: /ˌɪntɚˈstɪʃi.əm/

Definitions

1. A complex arrangement of small cavities within biological tissue that permits fluid flow and supports cellular networks
2. A network of interconnected microcavities found in bodily tissues that facilitates fluid movement and supports cells
3. A structure consisting of fluid-filled spaces within tissue that aids in nutrient transport and cellular interaction

Etymology: The word "interstitium" is built from two Latin parts: "inter," meaning "between," and "sistere," meaning "to stand" or "to place." Put together, the Latin noun meant something like "a space standing between things," and in classical Latin it carried that plain sense of an intervening interval, a gap in time or space. English took the word from Latin, so its sense stayed close to that gap-in-between idea for a long time. Its modern use in anatomy is a much later development. Medical writers applied it to a body structure that had been described only recently: a network of fluid-filled spaces within connective tissue, spread throughout the body, which the older picture of the body as a set of solid organs and membranes had largely overlooked. The Latin word already described a space between things, so it fit the discovery well, and the term now names those tissue spaces specifically.