01:830:301 Lecture Notes - Lecture 18: Secondary Somatosensory Cortex, Postcentral Gyrus, Substantia Gelatinosa Of Rolando
2 May 2016
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Document Summary
Benefits of pain perception- sensing dangerous objects. Touch sensations travel as far as 2 meters to get from skin and muscles of feet to brain. Info must pass through spinal cord: spinothalamic pathway- carries most of the info about skin temperature and pain (slower, dorsal column-medial lemniscal (dcml) pathway- carries signals from skin, muscles, tendons, and joints. Touch sensations are represented somatotopically in the brain: primary somatosensory cortex called s1; secondary somatosensory cortex called s2, analogous to retinotopy found in vision, adjacent areas on skin connect to adjacent areas in brain. Homunculus- maplike representation of regions of the body in the brain: brain contains several sensory maps of body in different areas of s1 and s2. Phantom limb- sensation perceived from physically amputated limb of the body: parts of brain is listening to missing limbs not fully aware of altered connections, so they attribute activity in these areas to stimulation from missing limb.
