Final answer:
Sensitization is a biological phenomenon where nociceptors lower their threshold to painful stimuli and their receptive fields expand. This makes the nociceptors more responsive to stimuli, resulting in increased pain sensitivity. Receptor density related to this process can be assessed using the two-point discrimination test.
Step-by-step explanation:
In a phenomenon called sensitization, nociceptors develop ongoing activity, along with a decrease in the thresholds to noxious stimuli and an increase in the size of receptive fields. Sensitization can be understood by studying the properties of nociceptors, which are specialized sensory neurons that respond to potentially damaging stimuli by producing pain sensations. They are found in various parts of the human body, both internally and on the surface. During sensitization, these nociceptors become more responsive to stimuli that are typically painful, such as extreme heat, pressure, or chemical irritation.
The density of different types of receptors in the skin can be estimated using a two-point discrimination test. This test involves two sharp points being applied to the skin at varying distances, helping to determine the size of the receptive field of a single sensory receptor. Larger receptive fields suggest lower receptor density, while smaller receptive fields indicate higher density. The results of such tests are crucial in understanding the principles of somatosensory reception and perception, including how nociceptors function during sensitization.