Morphine: Difference between revisions

In the brain, morphine works by altering the body's perception of pain. It binds to mu-receptors in the brain and keeps them from receiving pain signals<ref name=toxipedia/>. When morphine binds to and activates the mu-receptors, it also causes sedation, euphoria, physical dependence, and respiratory depression<ref name=newsmedical2/>. Morphine binds to the mu-receptors at the same sites that endorphins and dynorphins usually do. Endorphins and dynorphins are responsible for relieving pain or anxiety when a person is injures, and since morphine can bind to the mu-receptors in much greater quantities than endorphins normally do, it creates feelings of euphoria<ref name=enotes>[http://www.enotes.com/drugs-substances-encyclopedia/morphine/effects-body]</ref>. Morphine also attaches to GABA inhibitory interneurons that control the inhibition of pain. The morphine also binds to the descending pain inhibitory pathway in the spinal cord, where it inhibits the release of neurotransmitters in the opioid receptors<ref name=drugbank>[http://www.drugbank.ca/drugs/DB00295]</ref>. This decreases the amount of pain stimuli that reach the brain from the body<ref name=nda>[http://www.nda.ox.ac.uk/wfsa/html/u03/u03_016.htm]</ref>. Morphine can bind to the opioid receptors because it has the same B-phenylthylamine unit that endorphins have. LSD and many other hallucinogens also possess this unit and can bind to the same sites<ref name=toxipedia/>.

== Chemical Structure ==