For example, a peripheral neuropathy caused by a vitamin deficiency can be treated -- even reversed -- with vitamin therapy and an improved diet. Likewise, nerve damage brought on by alcohol abuse can often be stopped and improved by avoiding alcohol.
2. Vascular tissue - xylem and phloem in leaves form in strands called veins. Xylem forms on the upper side of a vein (on a vertical leaf, on the side next to the stem), and phloem on the lower side (side away from the stem). a. Veins are like a leaf's fingerprint and can be used to identify plants.
1 Sugar diffuses from the mesophyll in the leaf to the phloem cells in the vascular bundles. 2  Specialized cells called companion cells load the dissolved sugar into the sugar-conducting cells (called sieve elements) of the phloem by using cellular ATP as an energy source. - collections of similar cells that serve a specific purpose by functioning together. 2  Unlike animals, the major organs of plants (roots, stems, and leaves) are all composed of the same three tissues (epidermis, vascular tissues, and ground tissues).