Final answer:
Paralysis results in a loss of bodily functions below the lesion level due to spinal cord injury. For example, a hemisection can lead to the patient experiencing pain without fine touch on the paralyzed leg while having a normal pain response on the functional leg. A LMN lesion specifically causes flaccid paralysis, characterized by a loss of muscle tone.
Step-by-step explanation:
Paralysis results in a loss of somatic, sensory, and autonomic functions below the level of the lesion. This can occur due to injuries to the spinal cord where all areas of the body below the injury no longer receive nerve impulses from the brain. The degree of paralysis and loss of function depends on the level at which the spinal cord is injured - the lower the injury on the spine, the fewer the functions that are lost because all lower segments are cut off from the brain.
In the case of a hemisection of the spinal cord, the patient may experience differing sensory deficits on each side of the body. On the paralyzed leg, the patient may acknowledge painful stimuli but not fine touch or proprioceptive sensations due to damage to the dorsal column pathway which ascends ipsilateral to the sensation. Conversely, the spinothalamic pathway decussates immediately upon entering the spinal cord and ascends contralateral to the source, thereby bypassing the hemisection. Hence, the person would have a normal pain response on the functional leg.
A lesion on the Lower Motor Neuron (LMN) would result in flaccid paralysis, or paresis, which is a partial loss of voluntary muscle control and is characterized by a complete or partial loss of muscle tone. In contrast, an Upper Motor Neuron (UMN) lesion would retain muscle tone and manifest spasticity.