Biopsychology: Neurons and Synaptic Transmission 2 Flashcards
What happens when an electrical impulse reaches the end of a neuron?
It triggers the release of neurotransmitters from synaptic vesicles
Where does this release occur?
At the presynaptic terminal of the neuron
What are synaptic vesicles?
Tiny sacs that store and release neurotransmitters into the synapse
What are neurotransmitters?
Chemical messengers that diffuse across the synapse to the next neuron in the chain
What happens when a neurotransmitter crosses the synapse?
It binds to the postsynaptic receptor site, dendrites of the next neuron
What happens after the neurotransmitter binds to the receptor site?
The chemical message is converted back into an electrical impulse, restarting the transmission process
How do neurotransmitters fit into receptor sites?
Each neurotransmitter has a specific molecular structure that fits perfectly into a receptor site
Where are neurotransmitters found?
In the brain, spinal cord and some glands
Why do different neurotransmitters have different effects?
This is because they have unique structure that only bind to specifc recpetors
What are two types of effects that neurotransmitters can have on a neuron?
Excitatory and inhibitory effects
What determines whether a neuron will fire or not?
The summation of excitatory and inhibitory signals received by the postsynaptic neuron
What effect do inhibitory neurotransmitters have on the postsynaptic neuron?
They make the neuron more negatively charged, reducing the likelihood that it will fire
What effect do excitatory neurotransmitters have on the postsynaptic neuron?
They increase its positive charge, making it more likely to fire
What happens if a neuron receives both excitatory and inhibitory signals?
The overall effect, determines whether the neuron fires or remains inactive
If there are more inhibitory signals than excitatory signal, what happens?
The neurond oe snot fire, preventing signal transmission
If there are more excitatory signals than inhibitory signals, what happens?
The neuron fires, passing on the electrical impulse
What is summation in neural transmission?
The process of adding together excitatory and inhibitory influences on the postsynaptic neuron to determine when it fires
When does an action potential occur in the postsynaptic neuron?
Only if the sum of excitatory and inhibitory signals reaches the threshold
What happens once an action potential is triggered?
The electrical impulse travels down the neuron to pass a signal a along
