2. Synaptic Transmission Flashcards
Define synapse
The junction between a neurone and another neurone.
Or
Between a neurone and an effector cell
What is the synaptic cleft?
The tiny gap between the cells at the synapse.
What is the neurone called before the synapse?
The presynaptic neurone.
It has a knob called a synaptic knob.
What does the synaptic knob contain?
Synaptic vesicles filled with chemicals called neurotransmitters.
What happens when an action potential reaches the end of a neurone?
Neurotransmitters released into synaptic cleft.
They diffuse across to the postsynaptic membrane.
They bind to specific receptors.
When the neurotransmitters bind to receptors they might trigger an action potential, cause muscle contraction or cause hormone to be secreted.
Why are the synapses important?
It makes sure the impulses are unidirection - the impulse travels in one direction.
This is because the receptors are only on the postsynaptic nerve.
Why are the neurotransmitters removed from the cleft?
So the impulse response doesn’t keep occurring.
Either took back to presynaptic neurone or broken down by enzymes.
Name 1 neurotransmitter you need to know.
Acetylcholine.
What does acetylcholine bind to?
It binds to cholinergic receptors.
The synapses who uses acetylcholine are called cholinergic synapses.
