Sense organs receive chemical and physical information from what?
The environment
After sense organs receive information from the environment they do what?
Transmit what they have received to the nervous system which then processes the information and makes decisions to react appropriately.
Describe the brain.
- Made of 2 hemispheres
- Controls each hemisphere by the opposite side of the body
- Composed of gray matter (top) and white matter (inside)
- Site of intellectual faculties
What does gray matter do?
Processes information
What does white matter do?
Transmits information through nerve impulses
How does the brain stimulate muscles?
analyzes and makes sense of information (nerve impulses) from the senses and it produces nerve impulses to stimulate muscles
Describe the cerebellum.
- Similar composition to the brain
- Sits right under the brain
- Controls balance and motion
- Receives information on movements that a person wants to make and then analyzes body and muscle position, along with balance information from the inner ear to allow that movement to happen
Describe the brain stem.
- Positioned under the brain
- Connects the brain to the spinal cord
- Controls vital organs
- Acts as a gateway between the brain and the spinal cord
Describe the spinal cord.
- Long string of nerves
- Extends from the brain stem to the lower back
- Protected by the spine
- Transmits messages from the brain to the motor nerves
- Transmits information from the sensory nerves to the brain
What are motor nerves?
Nerves responsible for movement
What are sensory nerves?
Nerves associated to the senses
What makes up the central nervous system?
- Brain
- Cerebellum
- Brain stem
- Spinal cord
What makes up the Peripheral nervous system?
All of the nerves in the body
Cranial nerves are connected to what?
The brain, cerebellum, and brain stem
Spinal nerves are connected to what?
The spinal cord
Sensory nerves do what?
Carry nerve impulses from the sensory organs to the brain or spinal cord.
What do motor nerves do?
Transmit nerve impulses from the central nervous system to the muscles.
What are neurons?
They are cells of the brain, spinal cord, and nerves
What do neurons do when stimulated?
They transmit electrical impulses (nerve impulses)
What are neurons composed of?
A cell body surrounded by a cell membrane and containing organelles, along with the nucleus in the middle
What are dendrites?
Small branches that receive nerve impulses from a previous neuron or sensory nerve.
What does the axon do?
Sends nerve impulses out of the cell body and is tipped with nerve endings
What are axons covered with?
An insulator called the myelin sheath which protects and channels the nerve impulse.
What are synapses?
Neurons communicate with each other through gaps where information can be transferred from neuron to muscle or from neuron to neuron. This contact zone is called a synapse.
