Tree pine ("Pinus" species) the bark exudes sticky resin which deters attackers whereas in rubber trees ("Hevea brasiliensis") it is a milky latex that oozes out. The quinine bark tree ("Cinchona officinalis") contains bitter substances to make the bark unpalatable. Large tree-like plants with lignified trunks in the Pteridophyta, Arecales, Cycadophyta and Poales such as the tree ferns, palms, cycads and bamboos have different structures and outer coverings. Although the bark functions as a protective barrier, it is itself attacked by boring insects such as beetles. These lay their eggs in crevices and the larvae chew their way through the cellulose
Transdermal analgesic patch Transdermal analgesic patch A transdermal analgesic or pain relief patch is a medicated adhesive patch used to relieve minor to severe pain. There are two primary types of analgesic patches: patches containing counterirritants, which are used to treat mild to moderate pain, and patches containing fentanyl, a narcotic used to relieve moderate to severe pain in opioid-tolerant patients. Counterirritant patches contain ingredients such as capsaicin, methyl salicylate, camphor, or menthol, which are thought to mask pain signals by causing other sensations (itching, warmth, or cooling) in the areas they are applied to. In the United States, patches sold under the