Final answer:
Somatosensation involves the sense of touch, which encompasses modalities like pressure, vibration, temperature, and pain, and is mediated by receptors such as mechanoreceptors, thermoreceptors, and nociceptors distributed throughout the body.
Step-by-step explanation:
Somatosensation and the Gates Theory
Somatosensation, often simply referred to as the sense of touch, encompasses a variety of sensory modalities that are generally spread throughout the body rather than centralized in specialized organs. Included in somatosensation are perceptions such as pressure, vibration, light touch, tickle, itch, temperature, pain (nociception), proprioception, and kinesthesia. Mechanoreceptors in the skin and other tissues detect touch sensations, thermoreceptors are involved in temperature perception, and nociceptors are responsible for the detection of pain. These touch-related sensations are facilitated by mechanically gated channels in the cell membranes that open in response to physical stimuli, such as pressure or temperature changes, allowing ions to enter the cell and generate a sensory nerve impulse.
It is also important to understand the difference between sensation and the subsequent inference we might make from it. For instance, feeling cold is a direct sensation, while concluding that 'the air temperature must be dropping' is an inference based on that initial sensory exper