User:Bigpapijr2004/SCI structure

The nervous system is a marvelous and complex system. In a nutshell, it is the control center of the human body. Without it, the body cannot function. The nervous system is also the most complex system in the human body. The most obvious part is the brain. The nervous system also includes the spinal cord and the miles of nerves within the body. Did you know that there are 30,000 miles of nerves in a single human body! The nervous system is mainly divided into 2 main parts. The Central Nervous Sysytem (CNS) and the Peripheral Nervous System (PNS). The CNS is the main part of the nervous system. It contains the brain and the spinal cord. The CNS controls your behavior and personality. It also interprets oncoming sginals and repsonds to them. The other section of the nervou system is the PNS. It is basically all the parts of the nervous system that is not contained in the CNS. It is mostly made up of nerves that extend from the brain and the spinal cord. These nerves are called the cranial and spinal nerves, respectively. These cranial and spinal nerves serve as connections between the PNS and CNS. Then the PNS is divided into 2 more sections. One is the sensory division. It contains nerve fibers that carry impulses to the central nervous system from sensory receptors that are located throughout the body. Then there are two types of sensory fibers. One is the somatic which conveys info from the skin, muscle, skeletal muscles, and joints. The other type is the visceral. It conveys info from the visceral organs. Visceral organs is just a fancy word for internal organs. The other division of the PNS is the motor division. It carries message away from the CNS. Then the motor division can be divided into 2 parts. These 2 sections of the motor division is known as the voluntary and the involuntary system. The voluntary system cconnects fibers from the skeletal muscles to the CNS which controls movement. The involuntary system, as the name states, control and regulates involuntary movement such as breathing and your heartbeat. Now, like I said, the Nervous System is the most complex system in the human body and now you can see why!