Final answer:
A completely paralyzed person may still feel pain depending on the specific nature and location of their spinal cord injury because pain sensation transmitted via the spinothalamic pathway decussates upon entering the spinal cord, potentially bypassing the site of injury.
Step-by-step explanation:
The case presented involves spinal cord injury and the subsequent paralysis as well as sensation capability in a completely paralyzed person. When an individual experiences a severing or damage to the spinal cord, particularly if this occurs at the neck or higher regions, there may be complete paralysis below the point of injury. Paralysis affects all the areas of the body below the level of the spinal cord injury because nerve impulses are unable to travel back and forth between the brain and the rest of the body. In terms of sensation, the sensory deficits can be complex. Individuals with a damaged dorsal column pathway, which ascends ipsilaterally, could lose the sense of fine touch and proprioception like the lateral corticospinal tract. However, pain sensation, which is transmitted through the spinothalamic pathway, decussates or crosses over upon entering the spinal cord. Therefore, in the case of hemisection, pain sensation may still be present because the pathway crosses to the opposite side of the injury, essentially bypassing it. Thus, a completely paralyzed person could potentially still feel pain depending on the specific nature of their spinal cord injury.