Neurons, synaptic transmission and neurotransmitters Flashcards
What is a neuron?
It is a nerve cell, the basic unit of the nervous system.
What are the 6 main parts of the neuron?
Cell Body
Dendrites
Axon
Myelin Sheath
Nodes of Ranvier
Terminal Buttons
What is the cell body?
Also known as the Soma, includes a nucleus containing the genetic material of the cell.
What are dendrites?
Branch like structures sticking out of the cell body.
They carry impulses from other neurons to the cell body.
What is the axon?
A tube like structure, carries the impulses away from the cell body down the length of the neuron.
What is the myelin sheath?
Fatty layer that protects the axon and speeds up transmission of the impulse.
What are the nodes of ranvier?
Gaps in the myelin sheath which increase speed by forcing the impulses to ‘jump’ across the gaps along the length of the axon.
What are terminal buttons?
At the end of axons, not physically connected to the next neuron, but involved in communication across a gap known as the synapse.
What are the three types of neuron?
Sensory
Motor
Relay
What is depolarisation?
The rapid switch from negative to positive in the neuron.
What is the action potential?
An electrical impulse that is created when depolarisation passes a certain threshold.
What is synaptic transmission?
It is how neurons communicate with each other.
When the action potential reaches the end of the neuron, what is released?
Neurotransmitter from the vesicles.
What is excitation and inhibition?
The effect of neurotransmitters on neighbouring neurons.
What does excitation mean?
Dopamine for example causes excitation of the postsynaptic neuron by increasing its positive charge, making it more likely to fire.
What does inhibition mean?
Serotonin for example, inhibits the postsynaptic neuron maing the neuron more negatively charged and less likely to fire.
