Synapses Flashcards
What neurotransmitter are you required to know?
Acetylcholine
What does Acetylcholinesterase hydrolyse?
acetylcholine
What does acetylcholinesterase hydrolyse acetylcholine into?
choline and ethanoic acid
What happens after acetylcholinesterase hydrolyses acetylcholine into choline and ethanoic acid?
Choline and ethanoic acid diffuse back across the synaptic cleft and ATP is used to reform neurotransmitter molecules and store them in vesicles.
Where is acetylcholine released?
Cholinergic synapses and neuromuscular junctions
What are the 4 functions of synapses?
To transmit impulses between neurones
Ensure impulses only pass in 1 direction
Acclimatisation
Summation
What are the two types of summation?
Temporal summation
Spatial summation
What is temporal summation?
When a post synaptic neurone may only be stimulated if there are frequent action potentials in the presynaptic membrane.
What is spatial summation?
When a postsynaptic membrane may only be stimulated if several presynaptic neurones receive stimulation.
What is an excitatory drug?
A drug that stimulates the nervous system by creating more action potentials.
What is an inhibitory drug?
A drug that inhibits the nervous system by reducing the number of action potentials
What does the organophosphorus insecticide do?
Inhibits the enzyme acetylcholinesterase, so prolongs the effect of acetylcholine which remains in the synaptic cleft
What happens if acetylcholine remains in the synaptic cleft?
Repeated depolarisation of the postsynaptic neurone
What does repeated depolarisation of the postsynaptic neurone cause?
Repeated action potentials
What are the consequences of organophosphorus insecticides?
depletion of ATP, paralysis and death
