Final answer:
Parrison suggests that persistent changes in the spinal cord or anatomy of the spinal canal can lead to significant impacts on the central nervous system (CNS), potentially resulting in conditions like paralysis due to the interruption of nerve signals. The spinal cord is integral to sensory and motor functions, and damage to it can lead to permanent loss of function depending on the location and severity of the injury.
Step-by-step explanation:
Parrison proposes that prolonged alterations in spinal cord or spinal canal anatomy impart stretch, compression, or tensile forces to the spinal cord, with direct and indirect effects on the CNS.
Injuries to the spinal cord can lead to significant consequences including paralysis and loss of sensation and movement due to the interruption of nerve impulses between the brain and the body. The location and severity of the spinal cord injury determine the extent of paralysis and whether the effects are temporary or permanent. For instance, swelling can result in transient symptoms, but severe damage often results in permanent loss of function. Regrowth of nerve fibers is impeded by scar tissue and other factors that inhibit regenerative processes in the CNS.
The crucial role of the spinal cord in sensory and motor function is exemplified by the enlarged sections in the cervical and lumbar regions, which correspond to a higher number of neurons involved in the control of limbs. Damage to any part of this complex network, particularly to the ascending pathways such as the dorsal column or the spinothalamic pathway, can profoundly affect an individual's ability to process sensory information and perform voluntary movements.