Biopsychology - Neurons & Synaptic transmission Flashcards
What is a neuron?
and what are the 3 main types?
Cells that contain nerve impulses
There are 3 main types:
- Motor
- Sensory
- Relay
Whats a dentrite?
These carry impulses from the neighbouring neurons towards the cells body
What is the axon?
Carries impuluses away from the cell body down to the length of the neuron
What is the mylein sheath?
Protects the axon & speeds up the electical impulses
What are the Nodes of Ranvier?
The gaps segmenting the mylien sheath which speeds up the elctical impulses by forcing it to jump across the gaps along the axon
What are the Axon terminal?
The ends of axons which transmit messages to other cells via use of neurotransmitters at synapses
What does the sensory neuron do & where are they found?
Found in receptors such as the eyes & carry nerve impulses to the spinal cord & brain. When these reach the brain they are translated into sensations like vision.
What does the Motor neuron do & where are they found?
Found in the CNS & controls muscle movements.
When stimulated they release neurotransmitters that binds on muscles and triggers a response leading to movement
What does the Relay neuron do & where are they found?
Are found in the brain and spinal cord allowing the sensory and motor neuron to communicate
What is action potential?
An electrical impulse
What is the process of synaptic transmission?
1) Action potential reaches axon terminal
2) This causes the synaptic vesticles to merge with the membrane of the presynaptic neuron
3) This triggers the release of neurotransmitters
4) The neurotransmiters difuse across the synaptic gap reaching the post synaptic neuron
5) The neurotransmiters bind with the dendrites on the post synaptic cell
6) Once the receptors have been activated, they either produce excitatory or inhibitory effects on the post-synaptic cell.
7) If excitory the message will be more likely to be passed down ( vice versa)
What are Excitatory neurotransmitters?
Makes the post-synaptic cell more likely to fire e.g. Nonadrenaline
What are inhibatory neurotransmitters?
block or prevent the chemical message from being passed along any farther.
e.g. GABA
What is summation?
the process that determines whether or not an action potential will be generated by the combined effects of excitatory and inhibitory signals
What is synaptic transmission?
the process by which one neuron communicates with another.
