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Encyclopedia > Pain
Look up Pain in Wiktionary, the free dictionary.

Pain is an unpleasant sensation, ranging in intensity from slight through severe to indescribable. Sharp, throbbing, dull, nauseating, burning and shooting are among the qualities that pain can be experieced to have. Pain is a subjective experience. Scientifically it is separate and distinct from nociception.[1]. While pain often follows from nociception, it can also arise separate to nociception stimulus, and thus pain can be experienced in response to both external percieved events, i.e. seeing something, or internal cognitive events, i.e. remembering something. Also nociception frequently occurs without pain being felt. Image File history File links Information_icon. ... Shortcut: WP:-( Vandalism is indisputable bad-faith addition, deletion, or change to content, made in a deliberate attempt to compromise the integrity of the encyclopedia. ... This Manual of Style has the simple purpose of making things easy to read by following a consistent format — it is a style guide. ... Wikipedia does not have an article with this exact name. ... Wiktionary is a multilingual, Web-based project to create a free content dictionary, available in over 150 languages. ... In physiology, a stimulus is a detectable change in the internal or external environment. ...


Pain often has both a emotional quality and a sensed bodily location. In plain words; you feel bad, and your body hurts somewhere, when you experience pain.


The subjective reality of the localisation of pain to an area of the body is the basis for terms and phrases such as pain receptor, neck pain, refered pain, cutaneous pain, and "pain in my back". This useage of "pain" occurs frequently in much communication on this subject and contrasts to the scientific definition given above.


Pain can be a signal of tissue damage or inflammation, but this is often not the case. Despite it causing suffering, pain is a critical component of the body's defense system. It is part of a rapid warning relay instructing the central nervous system to initiate motor neurons in order to minimize detected physical harm. Lack of the ability to experience pain, as in the rare condition Congenital insensitivity to pain or Congenital Analgesia, can cause various health problems. Biological tissue is a collection of interconnected cells that perform a similar function within an organism. ... Inflammation is the first response of the immune system to infection or irritation and may be referred to as the innate cascade. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... With regard to living things, a body is the integral physical material of an individual, and contrasts with soul, personality and behavior. ... A diagram showing the CNS: 1. ... In vertebrates, motoneurons (also called motor neurons) are efferent neurons that originate in the spinal cord and synapse with muscle fibers to facilitate muscle contraction and with muscle spindles to modify proprioceptive sensitivity. ... Harm can be defined as causing physical or psychological/emotional damage or injury to a person, animal or other entity. ... Congenital insensitivity to pain (or congenital analgia) is a rare condition where a child cannot feel (and has never felt) physical pain. ...


The two most common forms of pain reported in the U.S. are headache and back pain. Pain is also a term specifically used to denote a painful uterine contraction occurring in childbirth. A headache (medically known as cephalalgia, sometimes spelled as cephalgia) is a condition of pain in the head; sometimes neck or upper back pain may also be interpreted as a headache. ... To meet Wikipedias quality standards, this article or section may require cleanup. ...


The word "pain" comes from the Latin: poena meaning punishment, a fine, a penalty. Latin was the language originally spoken in the region around Rome called Latium. ...

Contents

Types of pain

Pain can be classified as acute or chronic.

  • Acute pain is defined as short-term but extreme pain that comes on quickly but last only for a brief period of time. Acute pain is the body's warning of present damage to tissue or disease. It is often fast and sharp followed by aching pain. Acute pain is centralized in one area before becoming somewhat spread out. This type of pain responds well to medications.
  • Chronic pain was originally defined as pain that has lasted 6 months or longer. It is now defined as pain that persists longer than the normal course of time associated with a particular type of injury. This constant or intermittent pain has often outlived its purpose, as it does not help the body to prevent injury. It is often more difficult to treat than acute pain. Expert care is generally necessary to treat any pain that has become chronic, and coordinated treatment from an interdisciplinary health care team, including medical physicians, physical therapists, and psychologists or psychiatrists, often beneficial. An anterior cingulectomy, neurosurgery that disconnects the anterior cingulate gyrus, can be used in extreme cases to treat chronic pain. Post-surgery the patient will still feel the sensation of pain, but not the accompanying emotion. There have been some theories that not treating acute pain properly can lead to chronic pain.[2]

The experience of physiological pain can be grouped according to the source and related nociceptors (pain detecting neurons). Chronic pain was originally defined as pain that has lasted 6 months or longer. ... A nociceptor is a sensory receptor that sends signals that cause the perception of pain in response to potentially damaging stimulus. ... Drawing by Santiago Ramón y Cajal of neurons in the pigeon cerebellum. ...

  • Cutaneous pain is caused by injury to the skin or superficial tissues. Cutaneous nociceptors terminate just below the skin, and due to the high concentration of nerve endings, produce a well-defined, localized pain of short duration. Examples of injuries that produce cutaneous pain include paper cuts, minor cuts, minor (first degree) burns and lacerations.
  • Somatic pain originates from ligaments, tendons, bones, blood vessels, and even nerves themselves. It is detected with somatic nociceptors. The scarcity of pain receptors in these areas produces a dull, poorly-localised pain of longer duration than cutaneous pain; examples include sprains and broken bones.
  • Visceral pain originates from body's viscera, or organs. Visceral nociceptors are located within body organs and internal cavities. The even greater scarcity of nociceptors in these areas produces pain that is usually more aching and of a longer duration than somatic pain. Visceral pain is extremely difficult to localize, and several injuries to visceral tissue exhibit "referred" pain, where the sensation is localized to an area completely unrelated to the site of injury. Myocardial ischaemia (the loss of blood flow to a part of the heart muscle tissue) is possibly the best known example of referred pain; the sensation can occur in the upper chest as a restricted feeling, or as an ache in the left shoulder, arm or even hand. Referred pain can be explained by the findings that pain receptors in the viscera also excite spinal cord neurons that are excited by cutaneous tissue. Since the brain normally associates firing of these spinal cord neurons with stimulation of somatic tissues in skin or muscle, pain signals arising from the viscera are interpreted by the brain as originating from the skin. The theory that visceral and somatic pain receptors converge and form synapses on the same spinal cord pain-transmitting neurons is called "Ruch's Hypothesis".
  • Phantom limb pain is the sensation of pain from a limb that has been lost or from which a person no longer receives physical signals. It is an experience almost universally reported by amputees and quadriplegics.
  • Neuropathic pain, or "neuralgia", can occur as a result of injury or disease to the nerve tissue itself. This can disrupt the ability of the sensory nerves to transmit correct information to the thalamus, and hence the brain interprets painful stimuli even though there is no obvious or known physiologic cause for the pain.

In zootomy and dermatology, skin is an organ of the integumentary system made up of multiple layers of epithelial tissues that guard underlying muscles and organs. ... This article is about skin in the biological sense. ... In medicine, a burn is a type of injury to the skin caused by heat, electricity, chemicals, or radiation (an example of the latter is sunburn). ... Definition A cut is an injury that results in a break or opening in the skin. ... A ligament is a short band of tough fibrous connective tissue composed mainly of long, stringy collagen fibres. ... A tendon (or sinew) is a tough band of fibrous connective tissue that connects muscle to bone, or muscle to muscle. ... The arterial system The blood vessels are part of the circulatory system and function to transport blood throughout the body. ... Nerves (yellow) Nerves redirects here. ... A sprain (from the French espraindre - to wring) is an injury which occurs to ligaments caused by a sudden overstretching (for the muscle injury, see strain). ... In biology, an organ is a group of tissues which perform some function. ... Referred pain is an unpleasant sensation localised to an area separate from the site of the causative injury or other painful stimulation. ... This article needs to be cleaned up to conform to a higher standard of quality. ... The heart and lungs, from an older edition of Grays Anatomy. ... The Spinal cord nested in the vertebral column. ... Illustration of the major elements in a prototypical synapse. ... The gate control theory of pain of Ron Melzack and Patrick Wall arises from evolutionary psychology. ... Amputation is the removal of a body extremity by trauma or surgery. ... Quadriplegia, also known as tetraplegia, is a symptom in which a human experiences paralysis of all four limbs, although not necessarily total paralysis. ... Neurasthenia was a term first coined by George Miller Beard in 1869 to describe a condition with symptoms of fatigue, anxiety and pessimism. ... To meet Wikipedias quality standards, this article or section may require cleanup. ...

Selected common and serious causes of pain by region

Image File history File links Information_icon. ...

Head and neck

Temporal arteritis, also called giant cell arteritis (GCA) is an inflammatory disease of blood vessels (most commonly large and medium arteries of the head). ... In medicine, a trauma patient has suffered serious and life-threatening physical injury resulting in secondary complications such as shock, respiratory failure and death. ... Otalgia is ear pain or an earache. ... Otitis media is an inflammation of the middle ear segment of the ear. ... In medicine, a trauma patient has suffered serious and life-threatening physical injury resulting in secondary complications such as shock, respiratory failure and death. ... In medicine, a trauma patient has suffered serious and life-threatening physical injury resulting in secondary complications such as shock, respiratory failure and death. ... A headache (medically known as cephalalgia, sometimes spelled as cephalgia) is a condition of pain in the head; sometimes neck or upper back pain may also be interpreted as a headache. ... Tension headaches, which were recently renamed tension-type headaches by the International Headache Society, are the most common type of headaches. ... Cluster headaches are rare, extremely painful and debilitating headaches that occur in groups or clusters. ... Cancer is a class of diseases or disorders characterized by uncontrolled division of cells and the ability of these cells to invade other tissues, either by direct growth into adjacent tissue through invasion or by implantation into distant sites by metastasis. ... A cerebral or brain aneurysm is a cerebrovascular disorder in which weakness in the wall of a cerebral artery or vein causes a localized dilation or ballooning of the blood vessel. ... Sinusitis is inflammation of the paranasal sinuses from either bacterial, fungal, viral, allergic or autoimmune issues. ... Meningitis is inflammation of the meninges. ... A myocardial infarction occurs when an atherosclerotic plaque slowly builds up in the inner lining of a coronary artery and then suddenly ruptures, totally occluding the artery and preventing blood flow downstream. ... In medicine, a trauma patient has suffered serious and life-threatening physical injury resulting in secondary complications such as shock, respiratory failure and death. ...

Thorax

To meet Wikipedias quality standards, this article or section may require cleanup. ... Cancer is a class of diseases or disorders characterized by uncontrolled division of cells and the ability of these cells to invade other tissues, either by direct growth into adjacent tissue through invasion or by implantation into distant sites by metastasis. ... The menstrual cycle is the periodic change in a womans body that occurs every month between puberty and menopause and that relates to reproduction. ... Cancer is a class of diseases or disorders characterized by uncontrolled division of cells and the ability of these cells to invade other tissues, either by direct growth into adjacent tissue through invasion or by implantation into distant sites by metastasis. ... In medicine, a trauma patient has suffered serious and life-threatening physical injury resulting in secondary complications such as shock, respiratory failure and death. ... In medicine, chest pain is a symptom of a number of serious conditions and is generally considered a medical emergency, unless the patient is a known angina pectoris sufferer and the symptoms are familiar (appearing at exertion and resolving at rest, known as stable angina). // Causes Cardiopulmonary Important cardiovascular and... A myocardial infarction occurs when an atherosclerotic plaque slowly builds up in the inner lining of a coronary artery and then suddenly ruptures, totally occluding the artery and preventing blood flow downstream. ... It has been suggested that heartburn be merged into this article or section. ... Pancreatitis is inflammation of the pancreas. ... Hiatus hernia or hiatal hernia is the protrusion (or hernia) of the upper part of the stomach into the thorax through a tear or weakness in the diaphragm. ... Aortic dissection is a tear in the wall of the aorta (the largest artery of the body). ... A disease invented by matt jadrnak to get out of school and use as a FAKE excuse. ... Each year, shoulder problems account for about 1. ... Cholecystitis is inflammation of the gallbladder. ... The human musculoskeletal system is the musculoskeletal system that gives us the ability to move. ...

Abdomen

Abdominal pain can be one of the symptoms associated with transient disorders or serious disease. ... Peptic ulcer is a non-malignant ulcer of the stomach (called gastric ulcer) or duodenum (called duodenal ulcer). ... Gastroenteritis involves diarrhea or vomiting, with noninflammatory infection of the upper small bowel, or inflammatory infection of the colon, both part of the gastrointestinal tract. ... Hepatitis is a gastroenterological disease, featuring inflammation of the liver. ... Pancreatitis is inflammation of the pancreas. ... Cholecystitis is inflammation of the gallbladder. ... A myocardial infarction occurs when an atherosclerotic plaque slowly builds up in the inner lining of a coronary artery and then suddenly ruptures, totally occluding the artery and preventing blood flow downstream. ... This article is in need of attention. ... In medicine, stomach cancer (also called gastric cancer) can develop in any part of the stomach and may spread throughout the stomach and to other organs. ... Appendicitis, or epityphlitis, is a condition characterised by inflammation of the appendix. ... Pelvic inflammatory disease (or disorder) (PID) is a generic term for infection of the female uterus, fallopian tubes, and/or ovaries. ... Diverticulitis is a common disease of the bowel, in particular the large intestine. ... Kidney stones are solid accretions (crystals) of dissolved minerals in urine found inside the kidneys or ureters. ... Pyelonephritis is an ascending urinary tract infection that has reached the pyelum (pelvis) of the kidney (nephros in Greek). ... Cancer is a class of diseases or disorders characterized by uncontrolled division of cells and the ability of these cells to invade other tissues, either by direct growth into adjacent tissue through invasion or by implantation into distant sites by metastasis. ... Colorectal cancer, also called colon cancer or bowel cancer, includes cancerous growths in the colon, rectum and appendix. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... The human musculoskeletal system is the musculoskeletal system that gives us the ability to move. ... A strain is an injury which occurs to a muscle in which the muscle fibers tear as a result of overstretching. ... Cancer is a class of diseases or disorders characterized by uncontrolled division of cells and the ability of these cells to invade other tissues, either by direct growth into adjacent tissue through invasion or by implantation into distant sites by metastasis. ... It has been suggested that Slipped disc and Lumbar disc herniation be merged into this article or section. ... Degeneration of the intervertebral disc, which is often called degenerative disc disease (DDD) of the spine, is a common disorder of the lower spine. ...

Limbs

A myocardial infarction occurs when an atherosclerotic plaque slowly builds up in the inner lining of a coronary artery and then suddenly ruptures, totally occluding the artery and preventing blood flow downstream. ... The human musculoskeletal system is the musculoskeletal system that gives us the ability to move. ... Deep-vein thrombosis, also known as deep-venous thrombosis or DVT, is the formation of a blood clot (thrombus) in a deep vein. ... Peripheral vascular disease (PVD) is a disease in the large blood vessels of the arms, legs, and feet. ... Claudication, literally limping, is used as a medical term in various contexts. ... The human musculoskeletal system is the musculoskeletal system that gives us the ability to move. ... It has been suggested that Slipped disc and Lumbar disc herniation be merged into this article or section. ... Sciatica is a pain in the leg consequent to irritation of the sciatic nerve. ...

Joints

Osteoarthritis (OA, also known as degenerative arthritis or degenerative joint disease, and sometimes referred to as arthrosis or osteoarthrosis or in more colloquial terms wear and tear), is a condition in which low-grade inflammation results in pain in the joints, caused by wearing of the cartilage that covers and... Rheumatoid arthritis (RA) is traditionally considered a chronic, inflammatory autoimmune disorder that causes the immune system to attack the joints. ... It has been suggested that this article or section be merged with Calcium pyrophosphate deposition disease. ... Osteoarthritis (OA, also known as degenerative arthritis or degenerative joint disease, and sometimes referred to as arthrosis or osteoarthrosis or in more colloquial terms wear and tear), is a condition in which low-grade inflammation results in pain in the joints, caused by wearing of the cartilage that covers and... Septic arthritis is the proliferation of bacteria in joints and resultant inflammation. ... Hemarthrosis is a bleeding in joint spaces, often occurring in life-threatening cases such as hemophilia where the bleeding does not stop. ... In medicine, a trauma patient has suffered serious and life-threatening physical injury resulting in secondary complications such as shock, respiratory failure and death. ... In medicine, inflammatory bowel disease (IBD) is a group of inflammatory conditions of the large intestine and, in some cases, the small intestine. ... Psoriatic arthritis (or Arthropathic psoriasis) is a type of inflammatory arthritis that affects around 20% of people suffering from the chronic skin condition Psoriasis. ... It has been suggested that this article or section be merged with Reactive arthritis. ...

Physiology of nociception (commonly Physiology of pain)

Nociception, is the neurophysiological term for activity in specific nerve pathways transmitting physiological pain. These pathways transmit the nominally "painful" signals, though the signals are not always perceived as painful. Nociception is separate to, and distinct from, psychological pain This section, except where explicitly stated, uses "pain" in the sense of the subjective reality of the localisation of pain to areas where only nociception is, in fact, occuring. Neurophysiology is a part of physiology as a science, which is concerned with the study of the nervous system. ... Psychological pain refers to pain caused by psychological stress and by emotional trauma, as distinct from that caused by physiological injuries and syndromes. ...


Pain receptors

All pain receptors are free nerve endings. There are mechanical, thermal and chemical pain receptors. They are found in skin and on internal surfaces such as periosteum and joint surfaces. Deep internal surfaces are only weakly supplied with pain receptors and will propagate sensations of chronic, aching pain if tissue damage in these areas is experienced. NERVE ENDINGS SUCK PENIS!!! ...


Pain receptors do not adapt to stimulus. In some conditions, excitation of pain fibres becomes greater as the pain stimulus continues, leading to a condition called hyperalgesia. Hyperalgesia is an extreme sensitivity to pain, which in one form is caused by damage to nociceptors in the bodys soft tissues. ...


Nociceptors are the free nerve endings of neurons that have their cell bodies outside the spinal column in the dorsal root ganglion and are named based upon their appearance at their sensory ends. These sensory endings look like the branches of small bushes. The spinal cord is a part of the vertebrate nervous system that is enclosed in and protected by the vertebral column (it passes through the spinal canal). ... This is a dorsal root ganglion (DRG) from a chicken embryo (around stage of day 7) after incubation overnight in NGF growth medium stained with anti-neurofilament antibody. ...


Two main types of nociceptor, Aδ and C fibres, mediate fast and slow pain respectively. Thinly myelinated type Aδ fibres, which transmit signals at rates of between 6 to 30 metres per second mediate fast pain. This type of pain is felt within a tenth of a second of application of the pain stimulus. It can be described as sharp, acute, pricking pain and includes mechanical and thermal pain. Slow pain, mediated by slower, unmyelinated ("bare") type C pain fibres that send signals at rates between 0.5 and 2 metres per second, is an aching, throbbing, burning pain. Chemical pain is an example of slow pain. Aδ fibres are thin, myelinated fibers with a fast conduction velocity, or speed of travel of a nerve signal (2 to 30 m/s) and are associated with acute pain, the sharp pain that triggers reflexes which result in the pulling away from the stimuli (ie: yanking hand away from... C-fibers are unmyeliniated and as a result, have a slower conduction velocity, lower than 2 m/s. ...


Transmission of pain signals in the central nervous system

The perception of pain occurs when the nociceptors are stimulated and transmit signals through sensory neurons in the spinal cord. These neurons release glutamate, a major exicitory neurotransmitter that relays signals from one neuron to another. The signals are sent to the thalamus, in which pain perception occurs. From the thalamus, the signal travels to the somatosensory cortex in the cerebrum, where the pain is localised, and the individual becomes fully aware of the pain. Glutamate is the anion of glutamic acid. ... Chemical structure of D-Aspartic Acid, a common Amino Acid neurotransmitter. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... The lateral postcentral gyrus is a prominent structure in the parietal lobe of the human brain and an important landmark. ... The telencephalon (te-len-seff-a-lon) is the technical name for a large region within the brain which is attributed many functions, which some groups would class as unique features which make humans stand out from other species. ...


There are 2 pathways for transmission of pain in the central nervous system. These are the neospinothalamic tract (for fast pain) and the paleospinothalamic tract (for slow pain). A diagram showing the CNS: 1. ...

  • Fast pain travels via type Aδ fibres to terminate on lamina I (lamina marginalis) of the dorsal horn of the spinal cord. Second order neurons of the neospinothalamic tract then take off and give rise to long fibres which cross the midline through the grey commisure and pass upwards in the contralateral anterolateral columns. These fibres then terminate on the Ventrobasal Complex (VBC) of the thalamus. From here, third order neurons communicate with the somatosensory cortex. Fast pain can be localised easily if Aδ fibres are stimulated together with tactile receptors.
  • Slow pain is transmitted via slower type C fibres to laminae II and III of the dorsa horns, together known as the substantia gelatinosa. Second order neurons take off and terminate in lamina V, also in the dorsal horn. Third order neurons then join fibres from the fast pathway, crossing to the opposite side via the grey commisure, and travelling upwards through the anterolateral pathway. These neurons terminate widely in the brain stem, with one tenth of fibres stopping in the thalamus, and the rest stopping in the medulla, pons and mesencephalon. Slow pain is poorly localized.

The posterior horn (posterior column, posterior cornu, dorsal horn) of the spinal cord is dorsal (more towards the back) to the anterior horn. ... Substantia gelatinosa can refer to: Substantia gelatinosa of Rolando Substantia gelatinosa centralis This is a disambiguation page: a list of articles associated with the same title. ... Mostly enveloped by the cerebrum and cerebellum (blue), the visible part of brainstem is shown in black. ... Medulla in general means the inner part, and derives from the Latin word for marrow. In medicine it is contrasted to the cortex. ... Position of the pons in the human brain The pons (sometimes pons Varolii after Costanzo Varolio) is a knob on the brain stem. ... In biological anatomy, the mesencephalon (or midbrain) is the middle of three vesicles that arise from the neural tube that forms the brain of developing animals. ...

Analgesia

The gate control theory of pain, proposed by Patrick Wall and Ron Melzack, postulates that pain is "gated" by non-painful stimuli such as vibration. Thus, rubbing a bumped knee seems to relieve pain by preventing its transmission to the brain. Pain is also "gated" by signals that descend from the brain to the spinal cord to suppress (and in other cases enhance) incoming pain information. The gate control theory of pain, put forward by Ronald Melzack and Patrick Wall in 1962 [1], and again in 1965 [2], is the idea that physical pain is not a direct result of activation of pain receptor neurons, but rather its perception is modulated by interaction between different neurons. ...


The analgesia system is mediated by 3 major components : the periaquaductal grey matter (in the midbrain), the nucleus raphe magnus (in the medulla), and the pain inhibitory neurons within the dorsal horns of the spinal cord, which act to inhibit pain-transmitting neurons also located in the spinal dorsal horn. Periaqueductal Gray (PAG; also called the central gray) is the midbrain grey matter that is located around the cerebral aqueduct within the midbrain. ... In biological anatomy, the mesencephalon (or midbrain) is the middle of three vesicles that arise from the neural tube that forms the brain of developing animals. ... The nucleus raphe magnus, located directly rostral to the raphe obscurus, is afferently stimulated from axons in the spinal cord and cerebellum. ...


The body has several different types of opioid receptors that are activated in response to the binding of the body's endorphins. These receptors, which exist in a variety of areas in the body, inhibit firing of neurons that would otherwise be stimulated to do so by nociceptors. To meet Wikipedias quality standards, this article may require cleanup. ... Endorphins are endogenous opioid biochemical compounds. ...


Survival benefit

Despite its unpleasantness, pain is an important part of the existence of humans and other animals; in fact, it is vital to survival. Pain encourages an organism to disengage from the noxious stimulus associated with the pain. Preliminary pain can serve to indicate that an injury is imminent, such as the ache from a soon-to-be-broken bone. Pain may also promote the healing process, since most organisms will protect an injured region in order to avoid further pain. People born with congenital insensitivity to pain usually have short life spans, and suffer numerous ailments such as broken bones, bed sores, and chronic infection. A bone fracture is a medical condition in which a bone becomes cracked, splintered, or bisected as a result of physical trauma. ... Congenital insensitivity to pain (or congenital analgia) is a rare condition where a child cannot feel (and has never felt) physical pain. ... Bedsores, also called pressure sores or decubitus ulcers, are ulcers (sores) caused by prolonged pressure or rubbing on vulnerable areas of the body. ... An infection is the detrimental colonization of a host organism by a foreign species. ...


The study of pain has in recent years diverged into many different fields from pharmacology to psychology and neurobiology. It was even proposed that fruit flies may be used as an animal model for pharmacological pain research [1]. Pain is also of interest in the search for the neural correlates of consciousness, as pain has many subjective psychological aspects besides the physiological nociception.


Interestingly, the brain itself is devoid of nociceptive tissue, and hence cannot experience pain. Thus, a headache is not due to stimulation of pain fibers in the brain itself. Rather, the membrane surrounding the brain and spinal cord, called the dura mater, is innervated with pain receptors, and stimulation of these dural nociceptors (pain receptors) is thought to be involved to some extent in producing headache pain. Some evolutionary biologists have speculated that this lack of nociceptive tissue in the brain might be because any injury of sufficient magnitude to cause pain in the brain has a sufficiently high probability of being fatal that development of nociceptive tissue therein would have little to no survival benefit. A headache (medically known as cephalalgia, sometimes spelled as cephalgia) is a condition of pain in the head; sometimes neck or upper back pain may also be interpreted as a headache. ... The dura mater (from the Latin hard mother), or pachymeninx, is the tough and inflexible outermost of the three layers of the meninges surrounding the brain. ... In 1832, while travelling on the Beagle, naturalist Charles Darwin collected giant fossils in South America. ...


Since pain is defined as a signal of present or impending tissue damage affected by a harmful stimulus, the ability to experience pain or irritation is observable in most multicellular organisms. Even some plants have the ability to retract from a noxious stimulus. Whether this sensation of pain is equivalent to the human experience is debatable. Multicellular organisms are those organisms consisting of more than one cell, and having differentiated cells that perform specialized functions. ... Divisions Green algae Chlorophyta Charophyta Land plants (embryophytes) Non-vascular plants (bryophytes) Marchantiophyta - liverworts Anthocerotophyta - hornworts Bryophyta - mosses Vascular plants (tracheophytes) †Rhyniophyta - rhyniophytes †Zosterophyllophyta - zosterophylls Lycopodiophyta - clubmosses †Trimerophytophyta - trimerophytes Equisetophyta - horsetails Pteridophyta - true ferns Psilotophyta - whisk ferns Ophioglossophyta - adderstongues Seed plants (spermatophytes) †Pteridospermatophyta - seed ferns Pinophyta - conifers Cycadophyta - cycads Ginkgophyta...


Chronic pain, in which the pain becomes pathological rather than beneficial, is an exception to the idea that pain is helpful to survival. Furthermore, it is not clear what the survival benefit of sometimes extreme forms of pain (e.g. toothache) might be; and the intensity of some forms of pain (for example as a result of injury to fingernails or toenails) seem to be out of all proportion to any survival benefits.


Children and pain

Children have been proven to be markedly more sensitive to pain, but this fact is commonly dismissed as a fear reaction or a lack of coping abilities. Research has been carried out on how children can cope with pain due to increased sensitivity and it has been established that strategies that remove pain can help prevent long-term increases in sensitivity as the nervous system is still developing.


Ethnicity and pain

Pain may be experienced differently depending on ethnicity. A study by Liem et. al. suggests that redheads are more susceptible to thermal pain. [3]


Pain and alternative medicine

A recent survey by NCCAM found pain was the most common reason that people use complementary and alternative medicine (CAM). Among American adults who used CAM in 2002, 16.8% used CAM to treat back pain; 6.6% for neck pain; 4.9% for arthritis; 4.9% for joint pain; 3.1% for headache; and 2.4% used CAM to treat recurring pain. (Some survey respondents may have used CAM to treat more than one of these pain conditions.) The National Center for Complementary and Alternative Medicine or NCCAM, a division of the National Institutes of Health within the Department of Health and Human Services of the United States federal government, was established in October, 1991, as the Office of Alternative Medicine, which was re-established as the NCCAM... It has been suggested that this article or section be merged into Alternative medicine. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... Arthritis (from Greek arthro-, joint + -itis, inflammation; plural: arthritides) is a group of conditions where there is damage caused to the joints of the body. ... A headache (medically known as cephalalgia, sometimes spelled as cephalgia) is a condition of pain in the head; sometimes neck or upper back pain may also be interpreted as a headache. ...


One such alternative, traditional Chinese medicine, views pain as a qi "blockage" equivalent to electrical resistance, or as "stagnation of blood" – theorized as dehydration inhibiting metabolism. Traditional Chinese treatments such as acupuncture are said to be more effective for nontraumatic pain than traumatic pain. Traditional Chinese medicine shop in Tsim Sha Tsui, Hong Kong. ... QI, standing for Quite Interesting, is a comedy panel game television show hosted by Stephen Fry and shown on BBC Two and BBC Four. ... Electrical resistance is a measure of the degree to which an electrical component opposes the passage of current. ... Dehydration (hypohydration) is the removal of water (hydor in ancient Greek) from an object. ... Acupuncture (from Lat. ... In medicine, a trauma patient has suffered serious and life-threatening physical injury resulting in secondary complications such as shock, respiratory failure and death. ...


These claims have not been scientifically established.


Philosophy of pain

Main article: Pain (philosophy)

The concept of pain has played an important part in the study of philosophy, particularly in the philosophy of mind. The question of what pain actually consists in is, dependent upon what subject one approaches the question from, an open one. Many identity theorists would assert that the mental state of pain is completely identical with some physical state caused by various physiological causes. Many functionalists believe pain to be defined completely by its causal role (ie in the role it has in bringing about various effects) and nothing else. Theologians have also had much to say about the nature of pain and its various religious consequences. A much-talked-about issue in philosophy is the role of pain. ... A Phrenological mapping of the brain. ... Type physicalism (also known as Type Identity Theory, Type-Type theory or just Identity Theory) is the theory, in the philosophy of mind, which asserts that mental events are type-identical to the physical events in the brain with which they are correlated. ... Functionalism is a theory of the mind in contemporary philosophy, developed largely as an alternative to both the identity theory of mind and behaviorism. ... A causal system is a system that depends only on the current and previous inputs. ... Theology is literally rational discourse concerning God (Greek θεος, theos, God, + λογος, logos, rational discourse). By extension, it also refers to the study of other religious topics. ...


See also

Flogging demonstration at Folsom Street Fair 2004. ... Pain management (also called pain medicine) is the discipline concerned with the relief of pain. ... Congenital insensitivity to pain (or congenital analgia) is a rare condition where a child cannot feel (and has never felt) physical pain. ... A headache (medically known as cephalalgia, sometimes spelled as cephalgia) is a condition of pain in the head; sometimes neck or upper back pain may also be interpreted as a headache. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... Chronic pain was originally defined as pain that has lasted 6 months or longer. ... For other uses, see Torture (disambiguation). ...

References

  1. ^ IASP pain glossary
  2. ^ Dahl JB, Moiniche S (2004). "Pre-emptive analgesia". Br Med Bull 71: 13-27. PMID 15596866.
  3. ^ Liem EB, Joiner TV, Tsueda K, Sessler DI. Increased sensitivity to thermal pain and reduced subcutaneous lidocaine efficacy in redheads. Anesthesiology. 2005 Mar;102(3):509-14.
  • Guyton & Hall, (2005), Textbook of Medical Physiology (11th edition), Elsevier-Saunders

External links

Nervous system - Sensory system - edit
Special sensesVisual system | Auditory system | Olfactory system | Gustatory system
Somatosensory systemNociception | Thermoreception | Vestibular system |
Mechanoreception (Pressure, Vibration & Proprioception)

  Results from FactBites:
 
Pain - Wikipedia, the free encyclopedia (2525 words)
Slow pain is transmitted via slower type C fibres to laminae II and III of the dorsa horns, together known as the substantia gelatinosa.
Pain is also "gated" by signals that descend from the brain to the spinal cord to suppress (and in other cases enhance) incoming pain information.
Since pain is defined as a signal of present or impending tissue damage effected by a harmful stimulus, the ability to experience pain or irritation is observable in most multicellular organisms.
Pain Control (2059 words)
But pain is also modified by remembrances of past painful episodes, the special meaning of pain to each individual, the expectations of family and friends, religious upbringing and personal coping skills and strategies.
Pain from bone involvement is often described as achy, dull, localized and brought about by activity of the surrounding muscle groups or movement of the limb or spine.
Neuropathic Pain from nerve involvement is either related to direct tumor spread, such as the spread of colon cancer into the pelvis where the nerves to the legs or pelvic structures reside, or is secondary to irritating substances that tumors secrete near nerves.
  More results at FactBites »

 
 

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