Psychology 2036A/B Lecture : Psychology Notes
22 Apr 2012
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The significance of pain: although not enjoyable, the experience of pain serves important functions : produces withdrawal that prevents further injury. Serves as a basis of learning to avoid injurious objects/situations. Sets limits on activity and enforces inactivity and/or rest. Pain perception: when contact with injurious stimuli occurs, signals of tissue damage follow a particular route. Nociceptors of the afferent (sensory) neurons of the pns respond to the stimuli and they generate impulses that travel to the cns. Nociceptors are the afferent nerve endings that respond to pain stimuli. Nociceptors exist as free nerve endings, which means they are not encapsulated by any other tissue and they are freely exposed to the environment. Nociceptors or fibre types: a has thinly myelinated axons that carry thermal or mechanical nociception and is associated with sharp or pricking pain. They transmit impulses quickly (5 to 30 m/s). These fibres send messages through the thalamus and to the cerebral cortex.
