Function & Neurobiology of Pain
- Created by: Ria
- Created on: 05-01-16 11:19
View mindmap
- The Function and Neurobiology of Pain
- Learning Outcomes
- Describe the function of pain
- Differentiate between pain and nociception
- Discuss how the experience of pain can be modulated by cognitive and emotional factors
- Discuss the influence of cognitive distraction on pain
- What is pain?
- Pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage - International Association for the Study of Pain, 2011
- Pain exists when and where the client says it exists (McCaffery & Beebe, 1989)
- Purpose of pain: protect organism and increase chances of survival
- Pain as a warning: occurs before serious injury and promotes immediate withdrawal from stimulus
- Pain to facilitate healing: damaged joints, diseases or serious injuries causing pain sets limits on activities and enforces rest - essential for body's recuperative mechanisms
- Pain as education: can help to aid learning by avoiding injurious objects/ situations. In humans, this also involves language and symbols
- Pain can serve NO APPARENT PURPOSE
- Types of pain - duration
- Transient pain
- - Pain of brief duration and little consequence (Melzack and Wall, 1988). - Ubiquitous in everyday life, yet rarely a reason for seeking health care
- Acute pain
- - Pain of recent onset and probably limited duration. Usually identified by its temporal and causal relationship to injury and disease. - The local injury doesn't overwhelm the body's reparative mechanisms: healing can occur without medical attention although many look for medical care
- Chronic pain
- - Pain lasting a long period of time. - Commonly accepted arbitrary cut off between acute and chronic pain: 3-6 months. - Injury may exceed body's capability for healing. - Therapies providing transient pain relief don't resolve underlying pathological process
- Transient pain
- Why are Psychologists interested in pain?
- 1. Pain is highly prevalent
- 19% of Europeans suffer from some form of chronic pain. Back pain most common, then headache (Breivik et al., 2006).
- Estimated that 14m people suffer in England alone. 2011 - 31% M & 37% F reported chronic pain (BPS, 2015)
- Internet-based survey of US - chronic pain prevalence 30.7%. Higher for F (34.3%) then M (26.7%) & increased with age (Johannes et al., 2010)
- 2. Pain can have profound effects on QoL
- Evidence for probably anxiety in 38.2% of cases & probable depression in 30.1% (Pallant & Bailey, 2005)
- High fear of movement in 79.6% of patients with chronic lower back pain (Thomas et al., 2010)
- Associated with disturbances in family functioning, inc. emotional & physical intimacy, alcoholism & depression (Schwartz et al., 2001; Smith, 2003; Ferrari et al., 2007)
- 3. Pain can have profound effects on society
- Chronic pain & its burden places big costs on society
- Untitled
- UK - back pain costs NHS £1 billion per annum (Maniadakis & Gray, 2000)
- 4.6 million appointments worth £69 million (Belsey, 2003)
- Australia - total absent workdays @ 9.9 million annually, reduced effectiveness workdays @ 36.5 million annually (Van Leeuwen et al., 2006)
- 1. Pain is highly prevalent
- Nociception
- Functions of the nervous system
- Three main functions: sensory input, integration of data, & motor output
- NS provides info about threat or injury. Sensation of pain, by its inherent aversive nature, contributes to this function
- 2 major components to the somatosensory NS: subsystem for detection of mechanical stimuli (light, touch, vibration, pressure & cutaneous tension) & a subsystem for detection of noxious stimuli & temperature
- The neural process of encoding & processing noxious stimuli. Not a perception of pain - a response to a stimulus
- Noxious stimulus: an actually/ potentially tissue damaging event
- Nociceptors: "pain receptors", though not accurate as nociception doesn't always result in pain
- Nociceptors
- Respond to multiple energy forms that produce energy (thermal, mechanical & chemical stimuli) & provide info to the CNS regarding location & intensity
- Skin densely innervated by nociceptors. Also present in other body tissues (bone, muscle, joint capsules, viscera & blood vessels)
- Not found in brain or spinal cord
- A? & C-fibers major nociceptive nerve fibres
- A? (delta)-fibers associated with fast or first pain: discretely localised sharp, prickling pain. Responsible for sensation of quick, shallow pain specific in 1 area, & respond to a weaker intensity of stimulus than C fibers
- C-fibers associated with slow or second phase pain: less discretely localised burning, gnawing sensation quantitatively distinct to first pain. As stimulus strength increases, C fibers are recruited & an intense, burning pain is experienced which continues after cessation of the noxious stimulus
- Functions of the nervous system
- Cognitive modulation of pain/ GATE CONTROL THEORY
- Modulation of pain
- Brain doesn't passively receive pain info from the body, & instead actively regulates sensory transmission
- Experience of pain can be modulated by cognitive & emotional factors - Distraction a common tool (Johnson, 2005) - Manipulations inducing positive mood associated with reduction in pain perception & vice versa for NA
- Gate control theory of pain
- Untitled
- Modulation of pain
- The role of distraction in pain
- Congenital insensitivity to pain
- Learning Outcomes
Comments
No comments have yet been made