 |
 |
 |
 |
 |
 |
 |
 |
 |
|
|
|
|
|
|
|
|
|
The nervous system is an organ system in charge of sending messages to and from the brain and spinal cord to and from all parts of the body. It consists of the central nervous system and the peripheral nervous system. Another important part of the nervous system is the sense organs to which a special page is devoted.
It controls and coordinates the body functions.
It receives sensory impulses from the sensory organs through sensory nerve fibers, analyzes and interprets this information and starts the motor impulses which are carried to muscles and glands which act on these impulses and cause the body to react.
It helps the body learn from experience and stores these memories.
It coordinates all parts of the body to keep everything in balance.
Made up of the brain and the spinal cord.
Made up of sensory neurons, clusters of neurons called ganglia, and nerves connecting them to each other and to the central nervous system. These regions are all interconnected by means of complex neural pathways.
These are nerve cells. A neuron is an electrically excitable cell that processes and transmits information by electrical and chemical signaling. Chemical signaling occurs via synapses, specialized connections with other cells. Neurons connect to each other to form networks. A typical neuron possesses a cell body (often called the soma), dendrites, and an axon. Dendrites are filaments that arise from the cell body, often extending for hundreds of micrometers and branching multiple times, giving rise to a complex "dendritic tree". An axon is a special cellular filament that arises from the cell body and travels for a distance of up to a meter.
Encased in the skull for protection, the brain is made up of three major parts: the cerebrum which controls thinking and memory, the cerebellum which controls balance and coordination and the medulla oblongata which controls involuntary actions such as heartbeat, breathing and digestion. The adult brain weighs about 3 pounds. The brain contains about 100 billion nerve cells called neurons and trillions of helping cells called glia.
The major large set of nerves running down the spine and protected by the spinal column or vertebrae.
A subsystem of the peripheral nervous system, has the capacity, even when severed from the rest of the nervous system through its primary connection by the vagus nerve, to function independently in controlling the gastrointestinal system.
