The central nervous system, composed of the brain, spinal cord and an extensive neuron network, serves as the control center for all bodily functions. It functions as the transmitter and receiver as well as the pathway for information flow and determines how the body responds to changes in its internal and external environment.
Forebrain components, such as the cerebral cortex, the thalamus and hypothalamus, must process consciousness, thinking, sensory information and motor functions. The brainstem controls vision and hearing responses as well as balance and movement coordination. The medulla oblongata in the brainstem controls involuntary functions like breathing, heart rate and digestion.
The spinal cord consists of a cylinder of nerve fibers connected to the brain and protected by the spinal column. These nerve fibers form two pathways, one to carry sensory information to the brain and the other to carry information concerning motor function from the brain to arms, legs and other body parts. All cells in the central nervous system are composed of neurons that contain axons and dendrites with the ability to conduct and transmit signals. These components, bundled together into nerves, send impulses between the brain, spinal cord and other organs and tissues of the body to carry out the functions of the central nervous system.