Topic overview

Start with the big picture

Pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage, and it serves a protective role. The topic introduces nociceptive, neuropathic, inflammatory, and functional pain, including the distinction between somatic and visceral nociceptive pain. It follows nociceptor signals through the dorsal horn and ascending pathways, alongside descending inhibitory systems, and defines sensitization phenomena such as hyperalgesia and allodynia. The inflammation section covers its cardinal signs, key mediators, and the arachidonic acid pathways that produce prostaglandins and leukotrienes. It also contrasts acute inflammation, commonly associated with neutrophils, with chronic inflammation involving mononuclear cells and fibroblasts. Together, these mechanisms provide context for the pharmacologic and non-pharmacologic approaches introduced later in the lesson.