Neurons and synaptic transmission
- Created by: __Jess
- Created on: 02-12-22 15:17
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- Neurons and synaptic transmission
- Types of neurons
- Motor neurons
- Connects the CNS to effectors like muscles and glands.
- Sensory neurons
- Carry messages from the PNS to the CNS.
- They have long dendrites and short axons
- Relay neurons
- Connect the sensory neurons to motor neurons or other relay neurons
- They have short dendrites and short axons
- Motor neurons
- Structure of a neuron
- Cell body
- Includes a nucleus, which contains the genetic material of the cell
- Dendrites carry nerve impulses from neighbouring neurons to the cell body
- Axon carries impulses away from the cell body down the length of the neuron
- Covered by the myelin sheath which protects the axon and speeds up electrical transmission
- Segmented by the nodes of ranvier, which speed up transmission by forcing the impulse to jump across gaps
- Terminal buttons are at the end of the axon and communicate with the next neuron in the chain across the synapse
- Covered by the myelin sheath which protects the axon and speeds up electrical transmission
- Cell body
- Process of synaptic transmission
- Impulse travels down the axon of the presynaptic neuron
- This causes vesicles to release neurotransmitters into the synaptic cleft
- Neurotransmitters diffuse across the synaptic cleft
- The neurotransmitters bind with the receptor sites on the post-synaptic neuron
- Neurotransmitters diffuse across the synaptic cleft
- This causes vesicles to release neurotransmitters into the synaptic cleft
- Summation
- Some neurotransmitters make the postsynaptic neuron more likely to fire, some less likely
- If the net effect is excitatory, neuron is more likely to fire. If inhibitory, neuron is less likely to fire.
- Impulse travels down the axon of the presynaptic neuron
- Types of neurons
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