BIOL 031 Lecture Notes - Lecture 13: Posterior Grey Column, Receptive Field, Desiccation
17 Sep 2020
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Describe the pathway by which touch & pressure information travels to the cortex, including: nature of primary afferents (size, myelination), location of decussation, and area of termination. Nociceptors can respond to multimodal stimuli, if stimuli is potentially harmful. Frequent stimuli include; h+, histamine, cytokines, prostaglandins, and others. Pain information travels in the anterolateral pathway. Ion channels in neurons that open within a certain temperature range known as transient receptor proteins (trp proteins) Afferent axons are small and unmyelinated (no need for rapid communication to cns) Temperature information travels in the anterolateral pathway. Secondary afferent desiccates (crosses) immediately in spinal cord then synapses on tertiary afferent in thalamus. Describe how spatial acuity of touch & pressure relates to dedicated area within the somatosensory cortex. Areas requiring fine sensation/good spatial acuity (fingertips, mouth) have small receptive field, high receptive field density and large dedicated area in the somatosensory cortex.
