From cells to tissues

A tissue is a group of similar cells, bound together, that work as a team on one job. Muscle tissue is built from cells specialised to contract. Nerve tissue is built from cells specialised to carry signals. On their own, a single muscle cell can only shorten by a tiny, unnoticeable amount — but millions of them, organised into a tissue and then into a muscle, can lift real weight. Grouping specialised cells together is what lets the body do things a single cell never could manage alone.

Cells in a tissue are not just piled together randomly. They are held in place and supported by a matrix — material the cells themselves secrete around them, ranging from a thin gel to something as hard as bone — and they are often connected directly to their neighbours so signals and nutrients can pass between them efficiently.