CHAP 3 (nervous system, neurotransmitters/modulators, plasticity) Flashcards
(30 cards)
what does the CNS consist of?
what does it do?
brain+spinal cord
coordinates responses to sensory stimuli
What does the brain do?
receives+processes sensory stimuli from body and coordinates responses (emotions, movements, thought)
What does the spinal cord do?
2 points
carries sensory into from body to brain
carries motor info from brain to body
What is a spinal reflex?
2 points
involuntary+unconscious response to stimulus involving spinal cord, occurring without input from brain
occurs through series of neurons
What is the peripheral nervous system?
what does it consist of?
all nerves outside of CNS that carry messages between CNS and muscles, glands, and organs throughout body.
somatic NS
autonomic NS - parasympathetic, sympathetic, enteric
What does the somatic NS do?
carries sensory info to CNS and motor info to body
What does the autonomic NS do?
controls body’s internal environment in autonomous or self-regulated manner
What does the sympathetic NS do?
increases arousal, readying body for quick response
What does the parasympathetic NS do?
returns body to calm state after threatening/stressful situation
What is an unconscious response?
example?
response of NS that does not require awareness
sneezing/coughing
What is a conscious response?
example?
response of NS that requires awareness
scratching an itch
What is a neurotransmitter?
chemical produced by neurons that carries messages to other neurons/cells in NS, including muscles, organs, glands.
How do neurotransmitters transmit info across a neural synapse?
4 steps
1) neural impulse reaches axon terminals of presynaptic neuron
2) causes vesicles to release neurotransmitters into synaptic gap
3) neurotransmitters bind to receptor sites on dendrites of post-synaptic neuron
4) neurotransmitter either makes post-synaptic neuron more/less likey to fire
What is an excitatory effect?
increased likelihood that post-synaptic neuron will fire an action potential/neural impulse
What is glutamate?
main excitatory neurotransmitter in NS, involved with learning+memory
What is an inhibitory effect?
decreased likelihood that post-synaptic neuron will fire action potential/neural impulse
What is gamma-aminobutyric acid (GABA)?
main inhibitory neurotransmitter in NS, associated with anxiety, specific phobias, and Parkinson’s disease
What are neuromodulators?
subclass of neurotransmitters that alter strength of neural transmission, by increasing/decreasing responsiveness of neurons to neurotransmitter signals
What is dopamine?
what is involved in?
multifunctional neurotransmitter with excitatory+inhibitory effects
many CNS functions (movement, pleasure, attention, mood, cognition, motivation)
What is the reward pathway?
How does it relate to dopamine?
group of structures in brain activated by rewarding/reinforcing stimuli
brain increases dopamine along it, modulating brain activity.
What is serotonin?
inhibitory neurotransmitter that also acts as neuromodulator, influencing variety of brain activities
What is the serotonin pathway?
2 points
serotonins neuromodulatory system
originates in brainstem and extends to almost all areas of cerebrum (including cerebral cortex)
Difference between dopamine and serotonin
2 points
dopamine =motivation, reward, pleasure
serotonin = mood stability, well-being, emotional regulation
How is a neuromodulator different from a neurotransmitter?
3 points
released in a slower, diffuse manner
longer lasting
increase/decrease responsiveness of neurons to neurotransmitter signals
