Central Nervous System & Function of Neurotransmitters Flashcards
What does the CNS consist of?
Consists of the brain and spinal cord
What does the CNS do?
Guides our behaviour
Governs incoming messages from the body and also sends messages back from the brain to the body
How does the CNS send messages back from the brain to the body?
By passing electrical impulses around the body through nerve fibres made up of tracts of neurons
What are neurons? What is their role?
Tiny nerve cells that receive and transmit messages in the brain and around the rest of the body through impulses passed around the nervous system
What are dendrites like?
Finger like structures surrounding a cell body and form a tree like structure
What is an axon like?
Axon ends at the axon terminal
The axon is where the electrical signal from the cell body travels
An axon has more than one branch and at the end of each branch is a terminal button
What is the axon protected by?
Protected by the myelin sheath
What is the myelin sheath like?
The myelin sheath has breaks in it where the axon is not protected
These breaks are called the nodes of Ranvier
What are neurotransmitters?
Chemical messengers that act between the neurons in the brain, this allows the brain to process thoughts and memories
Where are neurotransmitters released?
Released into the synaptic gap and taken up by the receptors of dendrites of another neuron to send messages or they can be destroyed by enzymes or taken back up in the presynaptic neuron to be used again (reuptake)
What is Dopamine associated with?
Associated with pleasure feelings
Why is Dopamine linked to drug addiction such as Heroin?
Feelings from dopamine may be wanted so dopamine is linked to addiction as the individual carries out actions to get those feelings
What is Serotonin?
Neurotransmitter for happiness and good mood
What are low levels of serotonin linked to?
Linked to depression and anxiety
How do SSRIs work? (selective serotonin reuptake inhibitors)
Work by blocking the reuptake of serotonin - this leaves more serotonin at the synapse to be taken up again by the receptors of other neurons thus improving mood
