5.1.3: Neuronal Communication Flashcards
What is a synapse?
The gaps between the end of the axon of one neurone and the dendrite of another one
What happens when an action potential arrives at the synaptic knob?
Depolarisation leads to the opening of Ca2+ channels and Ca2+ diffuses into the synaptic knob
What occurs after vesicles containing neurotransmitters fuse with the presynaptic membrane?
The neurotransmitters are released into the synaptic cleft
How do neurotransmitters reach the post-synaptic membrane?
They diffuse down a concentration gradient across the synaptic cleft
What is required for the post-synaptic neurone to become depolarised?
Enough neurotransmitter must bind and enough Na+ must diffuse in to raise the membrane potential above -55mV
What happens to the neurotransmitter after it binds to the receptor?
It is degraded and released from the receptor
What is the role of acetylcholinesterase at a cholinergic synapse?
It degrades acetylcholine into choline and acetate
Fill in the blank: The neurotransmitter at a cholinergic synapse is _______.
acetylcholine
What is the function of the neurotransmitter re-uptake pump?
To transport the neurotransmitter back into the presynaptic neuron for recycling
True or False: The neurotransmitter must bind by the complementarity of shape to receptors on the post-synaptic membrane.
True
What ion channels open on the post-synaptic membrane when the neurotransmitter binds?
Na+ ion channels
What occurs when the Na+ channels close on the post-synaptic neurone?
The post-synaptic neurone can re-establish resting potential
What are the main components produced from the degradation of acetylcholine?
Choline and acetate
What initiates the process of neurotransmitter release at the synaptic knob?
The depolarisation of the synaptic knob
