Biopsychology: Neurons Flashcards
What are the three types of neurons?
- Motor neuron
- Relay neuron
- Sensory neuron
What is the role of a motor neuron?
Connect the CNS to effectors (e.g. muscles, axons)
What is the role of a relay neuron?
Connect sensory neurons to the motor and other relay neuron.
What is the role of a sensory neuron?
Carry messages from the PNS to the CNS.
What are the electrical signals called that pass between neurons?
Nerve impulses
Signals within neurons are transmitted _______. Whereas signals between neurons are transmitted ______.
- Electrically
- Chemically
Give the order of the neurons:
Sensory
Relay
Motor
Role of cell body:
Contains the nucleus which contains the genetic information of the cell.
Role of dendrites:
Carry nerve impulses from neighbouring neurons towards the cell body.
Role of axon:
Carries nerve impulses away from the cell body down the length of neuron.
Role of myelin sheath:
Insulates and protects the axon, speeding up the electrical transmission of the impulse.
Role of nodes of ranvier:
Speed up the transmission of the impulse by forcing it to ‘jump’ across the gaps along the axon.
Role of axon terminals:
Communicate with the neighbouring neuron across the synapse.
How are signals within neurons transmitted?
electrically
How are signals between neurons transmitted across the synapse?
Chemically
In what form are signals across the synapse in?
Neurotransmitters
At the end of an axon terminal, where are neurotransmitters released from?
Synaptic vesicles
What are neurotransmitters?
Chemicals that diffuse across the synapse to the next neuron in the chain.
On a dextrite of a neuron, where are neurotransmitters recieved?
Postsynaptic receptor site.
Neurotransmitters either have an ________ or _______ effect on the neighbouring neuron.
Excitatory or inhibitory.
What happens in an inhibitory response?
- Receiving neuron becomes negatively charged
- Less likely to fire.
Whether a postsynaptic neuron fires is decided by _________.
Summation
What happens in an excitatory response?
- Receiving neuron becomes positively charged.
- More likely to fire
Explain sumation:
- If the net effect on the postsynaptic neuron is inhibitory, the post synaptic neuron is less likely to fire.
- If the net effect on the postsynaptic neuron is excitatory the post synaptic neuron is more likely to fire.
