CNS and Neurotransmitters Flashcards
Name the parts of a neuron
Nucleus
Dendrite
Myelin Sheath
Axon terminal / Terminal Button
Node of Ranvir
What is the myelin sheath?
Fatty substances that insulate and protect the axon.
It speeds up transmission of information.
What is the axon?
Goes from cell body to terminal endings.
Neutral signal is passed down it.
The larger it is, the faster the transmission.
What is the terminal button / synaptic knob?
The end of the neuron.
Sends the signal to the surrounding neurons through neurotransmitters.
Gap at the end is the synapse.
What is the dendrites?
Extensions at the start of the neuron.
Increases surface area of a cell body.
They receive the info from other neurons and transmit electrical simulations to soma.
What is the cell body?
Contains the nucleus that looks after the cell.
What is a neurotransmitter?
A chemical released at the end of a neuron to pass an electrical message to another neuron, muscle or gland.
eg serotonin
Describe the process that our CNS goes through when we touch a hot pan.
- Touch a hot pan.
- Sensory neuron detects heat info and sends it to our CNS.
- CNS sends a message to the motor neurons.
- Motor neuron tell muscles to contract.
- Move hand away from hot pan.
What are neurons?
Cells that specialise in transmitting information around the body.
They use electricity and chemicals (neurotransmitters)
Give an overview of neurotransmission.
Action potential (electrical impulse) passed down presynaptic neuron.
Vesicles move to edge of synaptic button and dump neurotransmitters into synapse.
Receptors on the postsynaptic neuron take up neurotransmitters.
Postsynaptic neuron is either encouraged to fire or not fire.
Neurotransmitters in synapse are either broken down or transported back up into presynaptic neuron.
How does action potential affect vesicles?
Causes the vesicles to migrate to the cell membrane.
The action potential tells the vesicles how much neurotransmitter to release into the synapse.
What to vesicles do?
Contain neurotransmitters which are synthesised in the presynaptic cell and stored in the vesicles.
What do the neurotransmitters do in the synapse?
Float until they hit the correct receptor (like a key and lock)
If they are left, they can either be broken down by enzymes or taken back up into the presynaptic neuron by transporters.
What does heroin do to the brain?
- It turns into morphine and binds to opioid receptors.
- This stops the release of GABA.
- GABA inhibits the release of dopamine, so if GABA is not released there is more dopamine.
- The release of dopamine activates the reward system causing the user to feel euphoric and high.
-Also reduces pain as opioid stop transmission of pain signals to the brain.
What does cannabis do to the brain?
- Attaches to anandamide receptors, present all over the brain.
- Anandamide regulates mood, appetite, pain, thinking and emotions and also inhibits the release of dopamine.
- Cannabis allows release of dopamine, activating te reward system.
