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.
In palmate leaves the veins radiate outward from the base of the leaf like fingers spreading out from the palm of a hand. In parallel-veined leaves, the veins all run parallel from the base of the leaf to the tip. Most leaves have a petiole or a central stalk by which they are attached to the stem. Sessile leaves have no central stalk and are attached directly to the stem. Learn more about Botany.