4- Introducing Chemical Synapses and Neurotransmitters Flashcards
What are synapses?
The place where neurons meet
What are neurotransmitters?
The chemical messages between neurons
How do chemical synapses operate?
Via chemical communication
Where are the majority of chemical synapses?
In the brain
What muscle interaction are chemical synapses involved in?
Neuromuscular junctions
How is membrane potential affected?
By neurotransmitters binding to the postsynaptic receptor sites
What drives the membrane to become more positive/negative?
Movement of ions
What happens when there is an increase in membrane potential? (3 stages)
1- binding causes positive ions to enter cell
2- postsynaptic cell is depolarised so an AP is more likely to happen
3- generates an excitatory postsynaptic potential
What happens when there is a decrease in membrane potential? (3 points)
1- binding causes negative ions to enter cell
2- postsynaptic cell is hyperpolarised so AP is less likely to happen
3- generates an inhibitory postsynaptic potential
What does the flexibility of chemical synapses depend on?
The neurotransmitter and receptor
Where are neurotransmitters synthesised and stored?
The presynaptic neuron
Where are neurotransmitters released from?
The presynaptic axon terminal
What response must a neurotransmitter produce when experimentally applied?
A response the same as a natural response
Why is there a retrieval mechanism?
To remove the neurotransmitter from the synaptic cleft and prevent unwanted effects
