|
|
Polyneuropathy is a disease of the peripheral nervous system that causes muscle weakness and sensory dysfunction. To help understand it, let's first consider the human nervous system (in an incomplete and simplified form): The nervous system is part of the human organism that is responsible for sensory perception, sensory processing and reaction control. Together with the brain and spinal cord, they form the central nervous system (CNS). The entire rest of the nervous tissue is referred to as the peripheral nervous system (PNS). The central nervous system allows us to perceive things via the sensory organs. It is also the basis for all higher functions, among them consciousness, sense, thought and learning. The spinal cord in turn is a thick corn running down the spinal column, serving as the center for [http://www.wissen.de/lexikon/reflex-physiologie](reflexes that are performed without the involvement of the brain). It contains many nerve cells and nerve fibers that link the brain and the periphery. The purpose of the nerve cell – the smallest building block of the nervous system – is to record, forward and transmit sensory information. The peripheral nervous system (PNS) encompasses all nerves that run through the body like a network. The nerves convey information between the spinal cord or brain and the rest of the body. Like fine branches from a tree, the nervous fibers of the peripheral nervous system branch out from the spinal cord and connect to the "executive" organs like the musculature, the skin, or the internal organs. There is then an exchange of information using the control signals transmitted from the brain and the information forwarded via the brain. The nervous system is itself categorized by function into the somatic (voluntary) nervous system and the vegetative (autonomic or involuntary) nervous system. While the voluntary nervous system controls all processes subjugated to the consciousness and will (e.g. muscle movements), the vegetative nervous system is largely out of our directly voluntary control. It controls vital functions such as our heartbeat, breathing, blood pressure, digestion and metabolism. So what is polyneuropathy? The ability that a healthy person has to feel requires numerous sensors in the skin that specialize in different areas, among them touch, hot and cold perception, pain, and the forwarding of relevant information through the nervous system. In this connection, individual forms of polyneuropathy are disorders
|
