The nervous system is the system in our body that is responsible for coordinating and controlling the activities in the body both voluntary and involuntary. It is composed of the network of nerves called as neurons.
The nervous system has two main parts; one is the central nervous system and the other is the peripheral nervous system. The Brain and the Spinal Cord are the two parts that composed the central nervous system, while the peripheral nervous system is consist of all the parts of the entire nervous system but excluding the spinal cord and the brain.
The Central Nervous System
The two main parts of the central nervous system namely; the brain and the spinal cord are protected by the skull and the vertebral column. This system functions to receive messages from the outside environment as well as from the other parts of the body. It will then process and interprets the messages or information that was received. After the information is process, this system will sends and relays nerve impulses to the different glands and muscles in the body to be able to respond to the stimuli and to execute actions.
The brain can communicate with the rest of the body through the cranial and spinal nerves. The cranial nerves are the 12 pairs of nerves that are associated with the brain. The spinal nerves are the 31 pairs of nerves associated with the spinal cords. The brain and the spinal cord have their own functions.
The brain serves as the control center. It controls, process, and transmits all the messages to the different body parts. It directs the action and regulates body processes. It is the seat of all learning, intelligence, association and memory. (eyeglass stores )
All the processes, from receiving messages, coordinating messages, decision making and sending order will only take less than half a second for the brain to perform.
The spinal cord functions to pass information between the brain and the other parts of the body. It is responsible for controlling reflex behaviors.
The Peripheral Nervous System
Peripheral nervous system is composed of cranial nerves and the spinal nerves that have motor as well as sensory cells. It is further divided into somatic and autonomic nervous systems.
The neurons are connected to the voluntary muscles in the somatic nervous systems; while the neurons are connected to the smooth muscles and cardiac muscles (involuntary muscles) in the autonomic nervous systems.
The Autonomic Nervous System is further divided into two parts; the sympathetic and the parasympathetic nervous systems.
The sympathetic system is the system that speeds up the heart beat. The parasympathetic system becomes active when you are sleeping; it slows down if the body is active or under emotional stress.