Final answer:
Dull throbbing pain and sensitivity to heat are transmitted by C fibers, which carry both thermal and pain sensations along similar neural pathways through thermoreceptors.
Step-by-step explanation:
The dull throbbing pain and pain to heat that you are asking about is transmitted by C fibers. These fibers are a type of unmyelinated, slow-conducting nerve fiber that is responsible for carrying the sensations of dull, aching, and longer-lasting pain, as well as some thermal sensations. Thermal sensations, including the perception of heat, are facilitated by various receptors, such as the Ruffini endings which detect warmth.
However, when the thermal stimulus becomes too intense, it may progress to a sensation of pain. This pain and thermal sensations from both cold and heat stimuli are conducted along similar neural pathways, involving thermoreceptors, which send signals through the spinal cord, thalamus, and finally to the primary somatosensory cortex of the brain.