Biological - Neurotransmitters (theory) Flashcards
Neurotransmitters and their effects are often seen as _________
reductionist
Areas affected by neurotransmitters include:
○ Mood
○ Memory ○ Sexual Arousal Mental illness
A neuron consists of three parts
§ Soma (body)
§ Dendrites
§ Axon
Function of dendrites
Receive signals from nearby axons
Function of axons
Send signals to nearby dendrites.
How does a synapse form?
When the Axon of one neuron approaches a dendrite a synapse it formed.
Synaptic gap
○ A structure connecting two neurons.
Nature of transmisison between Synapses
Electrical and Chemical
Define a neurons process in the threshold of excitation
○ Once this is reached a brief pause called action potential is introduced.
○ It is all or none.
§ It either fires or not.
§ It will not fire weakly or strongly.
Define neurotransmitters
Chemical messengers
Relationship of neurotransmitter to neurons
○ They are constantly synthesized in the neuron
§ And moved to the axon terminal to be stored.
Function of neuron
§ A released transmitter is available in the synaptic gap for a short period before it is
□ Metabolized (destroyed).
□ Pulled back into the pre-synaptic axon terminal through Reuptake.
□ Reach the post-synaptic membrane and bind to one of the receptors on its surface.
§ When the neurotransmitter binds to a post-synaptic receptor it changes the membrane potential and contributes to activating an electrical pulse.
Two types of neurotransmitters
§ Excitatory neurotransmitters
□ Allows the impulse to cross the synapse.
§ Inhibitory neurotransmitters
□ Stop the impulse and prevent crossing the synapse.
Define agonists
Agonists are chemicals that enhance the action of a neurotransmitter.
Define Antagonists
® Antagonists are chemicals that counteract a neurotransmitter thus preventing a signal from being passed further.
