Nervous System Flashcards
(24 cards)
What are the major parts of the nervous system?
The brain, spinal cord, and nerves.
What are the two main parts of the nervous system?
- Central nervous system (CNS)
- Peripheral nervous system (PNS)
What does the central nervous system (CNS) consist of?
The brain and spinal cord.
What is the function of the peripheral nervous system (PNS)?
Connects the brain and spinal cord with other parts of the body.
What is the role of nerves in the nervous system?
Act as messengers carrying information from one part of the body to another.
What are nerves made up of?
Bundles of nerve fibres or nerve cells called neurons.
What is the longest nerve in the human body and where is it located?
1 meter long, found from the big toe to the middle part of the spine.
What do nerve cells (neurons) carry?
Electrical messages called nerve impulses.
At what speed do nerve impulses travel?
400 km/h.
What are the main components of a neuron?
- Dendrites
- Cell body
- Axon
- Myelin sheath
- Axon endings
What is the function of dendrites in a neuron?
Receive the message (chemical).
What does the cell body of a neuron contain?
All the components of a cell such as the nucleus and mitochondria.
What is the role of the axon in a neuron?
Passes along the message (electrical).
What is the function of the myelin sheath?
Insulates the axon and helps the message pass along more quickly.
What do axon endings do?
Release the message to the next cell (chemical - neurotransmitter).
What happens when the electrical message arrives at the axon endings?
It is converted to a chemical message (neurotransmitter).
What is a synapse?
The gap between two neurons.
How does a neurotransmitter function at the synapse?
Moves across the gap to trigger a new electrical message in the next neuron.
What are the types of neurons?
- Sensory neurons
- Motor neurons
- Interneurons
What do sensory neurons do?
Carry messages from the body to the CNS.
What is the function of motor neurons?
Carry messages from the CNS to the muscles and glands.
Where are interneurons found?
Only in the CNS.
How is the nervous system described in terms of traffic?
Like a one-way traffic system.
Fill in the blank: Neurons do not ______ other neurons or other cells.
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