Neurology, Hormone

QAHS BIOLOGY CORE TOPIC E4 Neurotransmitters and Synapses E4.1 State that some presynaptic neurons put forward partsynaptic contagious disease and former(a)s inhibit postsynaptic transmittance. Some presynaptic neurons excite postsynaptic transmission and others inhibit postsynaptic transmission. Synapses ar junctions between neurons Each neur star has many synapses with other neurons These synapses after part be repressing or stimulant drug An run authority in the post synaptic neuron will only occur if the potential difference at the axon hillock sources above the room access value.

An longing arrives done an excitant neuron b bely the rise in potential difference is insufficient to reach the scepter and so an so an treat potential does not occur two excitatory impulses arrive approximate to situateher and add up, but be still unable t0 reach the door and so an action potential does not occur Three presynaptic impulses arrive close together and add up, and this time do reach the doorsill so an action potential does occur An impulse arrives through an inhibitory neuron and this makes the resting potential more negative repayable to a flow of negative chloride ions into the axon hillock The trine rapid impulses that caused the action potential now have no effect as the threshold is not reached E4.2 Explain how decision-making in the CNS can result from the interaction between the activities of excitatory and inhibitory presynaptic neurons at synapses. Two aspects one functional and one structural are central to the decision making processes of the brain, namely interaction bet! ween the activities of excitatory and inhibitory pre-synaptic neurones at the synapses, operating(a) within unimaginably numerous connections that occur between the large numbers of neurones present; different types of connection pathways are set up between neurones: some of these relay impulses to other pathways, some spark off a single...If you want to get a full essay, separate it on our website: OrderEssay.net

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