Neurons Flashcards
The cell body
Holds nucleus
The nucleus
Holds genetic info
Dendrites
Carry nerve impulses from neighbouring neurons
Axon
Carry impulse away from cell body down neuron
Myelin sheath
Fatty layer, protects axon and speeds electrical transmission
Nodes of ranvier
Gaps between sheath, speeds up transmission by forcing it to jump across the gaps on the axon
Terminal buttons
End of the axon, communicated with the next neuron
What are the 3 neurons
Sensory, relay, motor
Sensory neuron
Found in receptors(eyes/skin)
Send nerve impulses to spinal cord/brain
Long dendrites-short axons
Relay neuron
Between sensory input and motor output
Send nerve impulses to brain/spinal cord
Short dendrites-short or long axon
Motor neuron
Found in CNS
Controls muscle movements
When stimulated-release neurotransmitters-bind to receptors on muscle movement
Short dendrite-long axon
synaptic transmission
Chemical impulse between neurons
Chemical impulse
Travels between neurons
Action potential
Electrical impulse that travels within a neuron-transforms the inside of an axon from a negatively charged to a positively charged channel
Electrical impulse
Travels within a neuron
Describe the direction of an electrical impulse
Received along dendrites and cell body, continue to travel down the axon towards the axon terminal
Describe how synaptic transmission occurs
- Action potential reaches axon terminal
- Calcium channel opens up
3.Ca2+ causes vesicles to release neurotransmitter - Neurotransmitter binds to neuroreceptor
- Triggers signal in post synaptic neuron, resulting in excitatory or inhibitory response
Excitatory
On switch
Excitation of post synaptic neurons- more likely to fire
Adrenaline
Inhibitory
Off switch
Inhibition of post synaptic neuron, less likely to fire
Serotonin/GABA
