Final answer:
The sensory homunculus exaggerates areas of high touch sensitivity on the body, like the fingers and face, by representing them with larger regions in the somatosensory cortex. The hands, specifically the fingers, have the largest representation.
Step-by-step explanation:
The sensory homunculus is a topographic representation of the body within the somatosensory cortex, highlighting how different regions of the body correspond to specific neurons processing stimuli. This map emphasizes areas of high sensory sensitivity, such as the fingers and the lower face, by allocating them larger regions within the cortex. Conversely, it downplays less sensitive regions, like the shoulders and back, mapping them to smaller areas of the cortex.
In response to the question, the part of the body with the largest region represented in the somatosensory cortex is the hands, particularly the fingers. This is due to the high concentration of sensory receptors in these areas, like the Meissner corpuscle and the Pacinian corpuscle, which are particularly attuned to touch and pressure.