Pain sensation

Opiates are useful analgesics because they reduce pain sensation without blocking feeling or other sensations. However, they also affect mood, iaduce euphoria, reduce mental acuity, and iaduce physical dependence. They can be immunosuppressive and dismpt other homeostatic processes through... 

Health Hazards Information - Recommended Persoruil Protective Equipment Fresh air mask for confined areas rubber gloves protective clothing full face shield Symptoms Following Exposure Will bum eyes and skin. The analgesic action may cause loss of pain sensation. Readily absorbed through skin, causing increased heart rate, convulsions, and death General Treatment for Exposure ... 

Pain sensation is modulated by glial cells communication with neuronal cells (reviewed by Scholz and Woolf 2007). The involvement of the CX3CL1/CX3CR1 pair in pain modulation has been recently demonstrated in different examples of experimental neuropathic pain induced by peripheral nerve injury or inflammation... 

Opium and its derivatives have been employed for centuries for the treatment of pain. Morphine was first synthesized in 1805 and has proven to be one of the most effective analgesic agents available [1], Morphine and its analogs are particularly useful because they diminish pain sensation while maintaining consciousness. However, opiates induce severe side-effects including respiratory depression, nausea, bradycardia and constipation and long-term use of opiates can cause addiction [2]. 

NGF has effects on the physiological responses of mature neurons. NGF acts as a target-derived trophic factor for pain neurons, which innervate peripheral tissues such as the skin. Inflammation of these peripheral tissues leads to local elevation of NGF synthesis and abundance. Elevated concentartions of NGF are responsible for the enhanced sensitivity to pain that accompanies inflammation. This is due to the ability of NGF to lower the sensory threshold of the pain fibers, leading to hyperalgesia. Nocioceptive sensory neurons mediating pain sensation are entirely dependent upon NGF for their survival as these cells are selectively lost in animal in which either the NGF or TrkA genes have been knocked out. These animals are insensitive to pain and live only a few weeks. 

Story GM (2006) The emerging role of TRP channels in mechanisms of temperature and pain sensation. Curr Neuropharmacol 4 183-196... 

Users of fentanyl analogues report that these drugs produce a rapid rush or euphoria that is similar to that felt with heroin, followed by a sedated, dream-like state. As analgesics, they also produce a profound loss of pain sensation and have common unwanted side effects such as sleepiness and constipation. However, because they are so potent, fentanyl analogues can... 

Bennett, G.J. and Xie, Y.K., A peripheral mononeuropathy in rat that produces disorders of pain sensation like those seen in man, Pain, 33, 87-107,1988. 

Capsaicin (52 Qutenza , NeurogesX, 2009), an active component of chili peppers belonging to genus Capsicum, was first isolated in pure and crystalline form by John Clough Thresh in 1876." Capsaicin is currently used in topical ointments to reheve the pain of peripheral neuropathy the burning and painful sensations associated with capsaicin (capsaicin does not actually cause a chemical bum, or any direct tissue damage at all) result from its chemical interaction with sensory neurons. Capsaicin, being a member of the vanilloid family, binds to the ion channel receptor vanilloid... 

The problem of alleviating painful sensations is as old as mankind itself. It can probably be said with a fair degree of confidence that the isolation of morphine, the oldest of the known pain-relieving drugs, from opioid plants in the 19th century served as the initiation for the intensive development of the chemistry, pharmacology, and pharmacy. 

Anesthetics increase membrane fluidity due to their lipid solubility and ability to cause disordering of packed fatty acid tails in the bilayer, which Is thought to Interfere with the ability of neurons to conduct signals such as pain sensation to the brain. 

The answer is E. Anesthetics are highly lipid-soluble and experiments with isolated membranes indicate that these molecules can dissolve in the hydrophobic center of the membrane bilayer. This causes a measurable increase in the membrane fluidity by disrupting the packed structure of phospholipids tails. This is considered to be the main, direct mechanism by which this class of drugs inhibits neurotransmission (pain sensations) in neurons. Hallucinogens and opiates may also affect membrane fluidity, but their effects occur by indirect mechanisms, resulting from changes in the protein or lipid composition of the membranes. 

Peripheral nerve functions are not affected equally by local anesthetics. Loss of sympathetic function usually is followed by loss of temperature sensation sensation to pinprick, touch, and deep pressure and last, motor function. This phenomenon is called differential blockade. Differential blockade is the result of a number of factors, including the size of the nerve, the presence and amount of myelin, and the location of particular fibers within a nerve bundle. For conduction to be effectively blocked, the local anesthetic must exert its effects over the distance between several nodes of Ranvier. Since the smallest nerves (C fibers) have no myelin, they can be most easily blocked thus, sympathetic functions often are blocked soon after a local anesthetic is applied to a particular nerve bundle. Small myelinated nerves have correspondingly short distances between nodes of Ranvier and therefore are often blocked next. These nerves subserve temperature and sharp pain sensation. Larger nerves then become blocked, accounting for the loss of function up to and including motor innervation. 

Postsynaptic Hj- and Hj-receptors are responsible for a variety of processes in the CNS. Hi-receptors mediate the maintenance of wakeful states, while Hj- and Hj-receptors participate in the regulation of blood pressure, body temperature, fluid homeostasis, and pain sensation. Presynaptic Hj-receptors serve as feedback inhibitors of the release of histamine, norepinephrine, and other neurotransmitters. 

Chemesthesis. The term chemesthesis has been introduced to classify thermal and painful sensations experienced in the mouth (26). Chemesthesis refers to a chemical sensibility (mouthfeel) in which certain chemicals direcdy activate nerve fibers at the level of the basal membrane in the mouth. The sensations are analogous to similar effects at the skin surface where there is a close anatomical and functional relationship. Sensations include the "hot" of capsaicin and piperine, which are active components of chili and pepper, the coolness of menthol and the irritation of chemicals such as salt at high concentrations [FIGURE 4]. Some of the descriptive terms used to make qualitative distinctions in food sensations include pungency, freshness, tingling, burning and sharpness. 

HT3 receptors in the gastrointestinal tract activate visceral afferent pain sensation via extrinsic sensory neurons from the gut to the spinal cord and central nervous system. Inhibition of afferent gastrointestinal 5-HT3 receptors may inhibit unpleasant visceral afferent sensation, including nausea, bloating, and pain. Blockade of central 5-HT3 receptors also reduces the central response to visceral afferent stimulation. In addition, 5-HT3-receptor blockade on the terminals of enteric cholinergic neurons inhibits colonic motility, especially in the left colon, increasing total colonic transit time. 

If Heart-fire influences its external related organ, the Small Intestine, patients may have dark urine with a foul smell which may be accompanied by urgent and painful sensations. 

These two herbs are able to eliminate damp-heat, increase urination and relax the tendons and muscles. They can be used to treat Bi syndrome due to damp-heat in the Middle-Jiao when burning, heavy and painful sensations of muscles are present. 

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