Abstract Primary afferent neurons that convey somatosensory modalities comprise two large. heterogeneous populations: small-diameter neurons that give rise to slowly conducting unmyelinated axonal C fibers and medium-to-large diameter neurons with fast myelinated A fibers. Despite these two major groupings. tools to differentiate between unmyelinated and myelinated primary afferent fi... https://www.footballmediaservices.com/product-category/tig-torch-pyrex-cup/