If you were able to walk into an opening cut into the center of a large redwood tree, when you exit from the middle of the trunk (stem) outward, you would cross, in order

If you were to cross a large redwood tree, like for an example a sequoia, from the middle of the trunk you would first cross the annual rings, indicators of the trunk growth over the years, then after that you would cross the phloem, the ''piping'' of the tree responsible for the transport of water throughout the tree and in the end you would cross the tree's bark, the protective layer on surface of the trunk.