CNS, NT, Recreational Drugs Flashcards
What does CNS stand for?
Central Nervous System
What is the CNS made up of? And what is the role of these separate parts?
The brain and the spinal cord
Brain processes all in incoming information from senses
The spinal cord connects the brain to the rest of the body, allowing messages to be passed from the body to the brain
What is the structure on the neuron?
Dendrites -> cell body -> nucleus -> axon (myelin sheath and nodes of ranvier) -> axon terminal -> terminal buttons
What is the myelin sheath
A lipid rich insulation layer, that speeds up the transmission of the electrical impulse
Nodes of ranvier
These act as little charging stations to prevent the signal from fading
What is a Neurotransmitter (NT)
A chemical messenger that acts between the neurons in the brain
Different NTs have different functions
What do Excitatory NTs do?
Stimulate the brain into action
What do Inhibitory NTs do?
Calm and regulate the brain
What is synaptic transmission
Where the action potential reaches the axon terminal and the the action potential is passed across the synapse via neurotransmitters, which are synthesised in vesicles
What is an antagonist drug
Limits effects of a NT
What is an agonist drug
Mimics the effect of a NT
How does heroin impact synaptic transmission
Heroin is an agonist and an antagonist
Agonist:
it is an opiate
Mimicks opiates naturally produced by our body, called endorphins both endorphins and heroin molecules bind to opioid receptors
Antagonist:
Once bound, limits the effects of the NT GABA
GABA normally inhibits excess DA production, so if there is little GABA, DA is produced in excess
So heroin indirectly increases DA which is associated with feelings of pleasure
How does Nicotine impact synaptic transmission
Nicotine is an agonist
It binds to ACh receptors, it is an agonist, meaning it mimicks the effects on the NT ACh,
When nicotine binds it has a stimulating effect causing the neurons to fire more frequently
It also interacts with DA receptors in the reward pathway, causing there to be an excess of DA produced
ACh is associated with thinking and learning
DA is associated with feelings of euphoria
