Central Nervous System
The central nervous system (CNS) consists of the brain (1) and the spinal cord (3).
http://en.wikipedia.org/wiki/File:Central_nervous_system.svg
The spinal cord is protected by vertebrae, or the backbone. It is basically a downward extension of the brain. Both the brain and the spinal cord are made up of neurons and supporting cells, which are also called glia. The glial cells significantly outnumber the neurons. Neurons and glial cells can be further categorized into more specific types. For example, there are sensory neurons, interneurons, and motor neurons. There are also many types of glia, but the major kind are Schwann cells.
The spinal cord receives sensory informationfrom the sensory neurons and brings it to the brain. It also receives motor information from the brain and brings it to effector cells (part of the motor neurons).
The brain receives sensory information from the spinal cord. It also receives sensory information from its own sensory neurons, like the olfactory and optic nerves. The brain interprets sensory information and formulates responses to send to motor neurons.
The brain is made up of three parts: the cerebrum, cerebellum, and the brain stem. The cerebrum controls senses like vision and touch. The cerebellum controls balance and coordination. The brain stem, or medulla, attaches to the spinal cord and controls digestion, breathing, and heartbeat.
The spinal cord receives sensory informationfrom the sensory neurons and brings it to the brain. It also receives motor information from the brain and brings it to effector cells (part of the motor neurons).
The brain receives sensory information from the spinal cord. It also receives sensory information from its own sensory neurons, like the olfactory and optic nerves. The brain interprets sensory information and formulates responses to send to motor neurons.
The brain is made up of three parts: the cerebrum, cerebellum, and the brain stem. The cerebrum controls senses like vision and touch. The cerebellum controls balance and coordination. The brain stem, or medulla, attaches to the spinal cord and controls digestion, breathing, and heartbeat.
http://www.myschoolhouse.com/courses/c/3/Images/brain.gif