Nervous System Flashcards
What does the nervous system do?
A: control and coordinate all functions of the body
What are the two main subdivisions of the nervous system?
- Central nervous system
- Peripheral nervous system
What is a neuron?
A: the scientific name for a nerve cells
What are the three basic structures of a neuron?
- Cell body
- Dendrites
- Axon
What two things does the cell body contain?
- Cytoplasm
- Nucleus
What do dendrites do?
A: receive messages, impulses, and send them through the cell body and the axon.
What is an axon? What does it do?
A: a single long fibre. Sends messages away from the cell body
What is the axon covered with?
A: a myelin sheath
What does the myelin sheath do?
A: increase speed of the nerve signals
How do impulses travel from one neuron to another?
A: across synapses
What are synapses?
A: spaces between the nerve cells
What is the jumping across synapses helped by?
A: neurotransmitters
Where do drugs affect the nervous system?
A: synapses
What are the three types of neurons?
- Sensory
- Motor
- Interneurons
Sensory neurons send information from where to where?
A: sensory receptors to the CNS
Where do motor neurons send information to?
A: away from the CNS to muscles or glands
Where do interneurons send information?
A: in between sensory neurons and motor neurons
Where are most interneurons located?
A: in the central nervous system
What is a stimulus?
A: a detectible change in the environment