The central nervous system is made up of the brain and spinal cord. The peripheral nervous system comprises the rest of the nervous system, a network of nerves that begins where the central nervous system ends, with spinal nerve roots that extend through passages in the vertebrae to supply nerve impulses to the organs and muscles while receiving nerve impulses from those same areas and sending them back to the brain. Damage to the peripheral nerves can impede sensory, motor or visceral function.
Sensory Impairment
Sensory nerves are those that provide the brain with information about pain, pressure and the spatial orientation of various body parts. Sensory nerves called nociceptors send nerve signals to the brain that alert it to the presence of potentially harmful influences that cause pain. When damage to the sensory nerves occurs, it may impair an individual's ability to feel pain and thus make the person vulnerable to further injury. Numbness is a common symptom of nerve damage.
The National Institute of Neurological Disorders and Stroke likens the effects of damage to the large sensory nerves of the hand and foot to that of wearing gloves or stockings. The ability to feel pressure or vibrations may be less sensitive over those areas, as if a layer of cloth is covering the skin.
Visceral Dysfunction
The autonomic nervous system is composed of nerves that regulate the function of the internal organs. The range of possible symptoms from autonomic nerve damage is as wide as the range of organ systems present in the body. It can affect the excretory, sexual and cardiovascular systems in devastating ways.
Damage to the autonomic nerves can result in life-threatening complications in rare instances, according to MedlinePlus. Irregular heartbeat, the inability to control body temperature, uncontrollable declines in blood pressure and gastrointestinal malfunction can result from autonomic nerve damage.
Muscle Weakness
When the motor nerves of the peripheral nervous system are damaged, the muscles that they supply suffer as well. Carpal tunnel syndrome is an example of a highly localized form of peripheral neuropathy, according to the University of Chicago Center for Peripheral Neuropathy. It results when there is compression of the median nerve, an offshoot of the brachial plexus that extends into the hand from the elbow. The compression occurs in the wrist area, where the nerve must pass through a compact anatomical complex of bones, tendons, blood vessels and muscles. This is commonly due to work-related repetitive activities. Along with the numbness associated with sensory nerve damage, carpal tunnel syndrome can cause weakening of the hand muscles to the point where an individual has difficulty holding a pen or cannot maintain a grip on small objects.
