How can multicellular animals use their dead cells?

Let’s consider everything with a specific example. Plants have conductive tissue. It consists of elongated living and dead cells. Their function is to carry water with dissolved mineral and organic substances through the plant from the root to all cells. Conducting cells play the role of a water conduit and it does not matter at all whether dead cells will pass a solution through themselves or live ones. Some organisms get rid of dead cells as they lose their function. The cell can flake off or decompose without harm to the body.