How Nerves Work 5 Flashcards
How is acetylcholine released from the axon terminal?
By exocytosis.
Define N-Plate potential.
Part of the synapse where the neurotransmitter binds and voltage gated channels are opened.
Describe the process of the neuromuscular junction.
Action potential in motor neurone opens voltage gated calcium channels in presynaptic terminal.
This triggers the fusion of vesicles and acetylcholine is released.
Diffuses across the synaptic cleft and binds to acetylcholine receptors.
This opens ligand gated sodium/potassium channels and evokes a graded potential.
Always depolarises adjacent membrane to threshold and opens voltage gated sodium channels to evoke a new action potential.
Acetylcholine is removed by acetylcholinesterase.
What is the important part of the membrane?
Folds for the receptors and gated channels.
Most neurotransmitters are ______ so can stay in a vesicle well but there are others like NO which are ______ and diffuse the second they are made to do their function.
Hydrophilic, Lipophilic
What are the 4 ranges of postsynaptic potentials?
Fast EPSPs (iontropic)
Slow EPSPs (metabotropic)
Fast IPSPs
Slow IPSPs
Excitatory postsynaptic potentials
Inhibitory postsynaptic potentials
What is an EPSP?
Postsynaptic potential that makes the postsynaptic neuron more likely to fire an action potential.
What is an IPSP?
A kind of synaptic potential that makes a postsynaptic neuron less likely to generate an action potential.
What is the anatomical arrangement of a synapse?
Axosomatic - attached to somas
Axodendritic - attached to dendrites
Axoaxonal - attached to other axons
Define convergence.
Multiple neurons giving signals to one neuron.
Define divergence.
One neuron giving signals to multiple neurons.
Define feedback inhibition.
Everytime a potential is sent, it sends inhibitor so only one signal will be sent then it’ll stop.
