bio-psych: neurons and synaptic transmission Flashcards
Define neuron
Nerve cells that process and transmit messages through electrical and chemical signals
Define sensory neuron
Carry messages from PNS to CNS
What is the structure of a sensory neuron?
-LONG dendrites
-SHORT axons
Define relay neuron
Connect sensory to motor or other relay neurons
What is the structure of a relay neuron?
-SHORT dendrites
-SHORT axons
Define motor neuron
Connect CNS to effectors (e.g muscles/glands)
What is the structure of a motor neuron?
-SHORT dendrites
-LONG axons
What % of neurons are found in the brain/visual system?
97%
When a neuron is in the resting state, the inside of the cell is what charge?
Negatively charged
When a neuron is activated by a stimulus, the inside of the cell is what charge?
Positively charged for split second
What does a positively charged inside cell cause?
Action potential
What does action potential cause?
Creates an electrical impulse that travels down the axon towards end of neuron
Define synaptic transmission
Neighbouring neurons communicate with each other by sending chemical messages across synapse (gap)
Define synapse
A gap between 2 neurons, that separates them
Define neurotransmitter
Chemicals released from synaptic vesicle that jump across the synapse from 1 neuron to another
What 2 functions do neurotransmitters produce?
-Either:
-Excitation
-Inhibition
Define excitation
Neurotransmitter (e.g adrenaline), increases positive charge of postsynaptic neuron
Increases likelihood = electrical impulse = passed on
Define inhibition
Neurotransmitter (e.g serotonin) increases negative charge of postsynaptic neuron
Decreases likelihood = electrical impulse = passed on
Define summation
Whether a post-synaptic neuron decides to fire
