The perception of pain serves as a defense system to maintain homeostasis, warning of injury that should be avoided and/or treated. Injured limbs actually inhibit voluntary movement to promote necessary healing processed (2). So essential is the painful response that those individuals born with congenital pain insensitivity do not react to pain, often resulting in severe, permanent tissue damage, and even premature death. A crucial concept in the definition of pain is that it is indeed a perception, therefore involving the brain's rumination and elaboration on corresponding input. This may be paralleled to another sensory perception, vision.
Selective activation of nociceptors can elicit the conscious occurrence of pain (Bear, Connors & Paradiso, 2007). The underlying questions remains, how is pain processed in the brain. Do we all process pain the same? What factors are responsible for contributing to the processing of pain? Damage to human tissue that would generate pain can be caused by numerous stimuli.
Innate immunity plays a critical role in central sensitization and in establishing acute pain as chronic condition. Moreover, inflammatory mediators also exhibit psychological effects, thus contributing towards emotional elements associated with pain. However, there is a considerable role of immune system as analgesic and in resolution of pain. This review also attempts to enlist various novel pharmacological approaches that exhibit their actions through modification of neuro-immune interface. Introduction One of the most vital functions of the nervous system is to provide information about the occurrence or threat of injury.
1) According to the International Association for the Study of Pain (IASP), pain is “An unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage.” As well as this definition the IASP also added an extensive list of side notes to help clarify what pain is. The list includes: Pain is subjective. For this reason this definition does not tie pain to the stimulus. Different people react to a stimulus in various ways. Similarly, the same person may respond differently to the same stimulus under different emotional circumstances.
The sensory pain is the quality of the pain experienced in a particular location and is often described as a sensational form of hurt. The affective pain is described as an emotional experience in which pain is perceived by the individual. “The perception of pain results from the brain’s processing of new sensory input with existing memories and emotions, in the same way that other perceptions are produced. Childhood experiences, cultural attitudes, heredity, and gender are factors that contribute to the development of each individual’s perception of and response to different types of pain. Although some people may be able physiologically to withstand pain better than others, cultural factors rather than heredity usually account for that ability” (Meldrum).
The dorsal horn of the spinal cord is the region of the CNS that controls the passage of pain signals by means of opening and/or closing the gate. Pain can only be perceived if reaches the brain. Events that cause excitation such pain signals and the release of excitatory or facilitatory chemicals cause the gate to open whereas inhibitory events such as competing nerve impulses caused by rubbing trigger closure of the gate. The gate can also be closed due to descending inhibition enhanced by relaxation or the use of pain-relieving medication such as morphine. The brain stem is responsible for controlling the transmission of pain signals via the ascending and descending pain pathways.
We also know that pain is an objective response to certain stimuli, there are neurons that sense and feel pain and there are nerve impulses that send these “painful” messages to the brain. What we don’t know is where the pain experience actually comes from. Understandably, we know pain happens or is perceived in the brain but is it an actual mechanical response that is controllable or is it just a sensation that the brain experiences. There are several theories and possibilities on why there can be such a separation and a divergence in people from the ones that can seemingly endure painful events and the ones that can’t. Three important claims that are related to pain are: one, pain is actually a perception, two, is that the brain mediates the suppression of pain through the “gate” in the spinal cord and three, is that the mind may be able to decide when the “gate” can open and how far open the “gate” will be.
We may wish to be invincible to pain, but pain has a purpose and it is a necessity to be felt. As humans with no natural armor, we fear pain and try to escape it; however, the rare disease of Congenital Insensitivity to pain reinforces and confirms that pain is the vital teacher essential to our survival, and above all we should all be grateful for pain. Pain can be felt in many different areas in various degrees. We all experience pain differently, but all pain is a property not only of the senses, but of our brain and our expectations as well (Myers 227). There are many different theories of how our bodies experience pain, but the most common is the Gate-Control theory.
Bond (1984) describes pain as being a personal and unique experience which arises in the brain due to injury to the body tissue, disease or due to biochemical changes in our bodies. There are two main types of pain, acute and chronic. Acute pain is experienced for a short time and usually has a specific cause and purpose such as injury t... ... middle of paper ... ...and Concepts,MACMILLAN PRESS LTD,USA. Barber,J.& Adrian,C.1982,Psychological Approaches to the management of pain,Brunner/Mazel INC,USA. Brannon, L.& Feist, J.2000, Health Psychology: An Introduction to Behaviour and Health ,4th edn ,Brooks/Cole,USA.
The underlying mechanism is not very well understood. It is essential to understand normal pain processing in order to understand the pathology in more detail. Normal pain processing involves receptors, nerve fibers and action potentials which help to carry the pain stimuli’s from the site of injury, up the afferent nerve, to the dorsal root ganglion which then relays the stimulus to the brain (Benoliel et al, 2012). There are 4 steps that make up the mechanisms of pain and they include transduction, transmission, modulation and perception. The pain originates in the periphery at the receptors in the end of nerves and can be in the form of heat, cold, mechanical or even chemical pain.