TOPIC 3: NEUROSCIENCE AND BEHAVIOUR Flashcards
phrenology
linked physical state and mind, study of bumps on your skull.
reductionism
philosophy that a complex system can be explained by reducing it to its component parts.
myelin sheath
- fatty cells surrounding axon
- increases processing speed of electric current.
- degeneration of myelin sheath can lead to multiple sclerosis
where is the neurone + or - when polarized
positive outside and negative inside
what’s the state when the neuron is polarized
resting potential
action potential
electrochemical process that produces a traveling electrical charge along the axon
depolarization
Na+ channels open briefly, Na+ enters
depolarization
K+ channels open, K+ exits
where does depolarization and repolarization occur
occurs as a wave down the length of the axon terminal button
ion pumps function
restores balance of Na+ and K+ ions
absolute refractory period
time after an action potential during which another action potential cannot begin
synapse
functional connection between neutrons
synaptic cleft
gap between terminal buttons of one neutron and dendrites of another neuron
how are messages given
carried across by neurotransmitters
neurotransmitters
chemical messenger released by traveling charge
excitatory
opens channels allowing inflow of positively charged ions
inhibitory
opens channels allowing outflow of positively charged ions or inflow of negatively charges ions.
when is it increased likelihood of neurone firing?
during excitatory state, decreased likelihood during inhibitory state
threshold
minimum activity needed for action potential to occur
all monoamines
- dopamine
- norepinephrine
- serotonin
all amino acids
- glutamate
- gamma-aminobutyric acid
- endorphins
acetylcholine
(ACh)
-excititory transmitter between motor neurone and muscles; learning and memory
- low levels of ACh associated with Alzheimers disease
- curare is antagonistic towards ACh, and blocks it.
- nicotine ACh receptors activate by nicotine (agonist)
curare
antagonistic : blocks ACh actions on muscles
dopamine
(DA)
- voluntary movements, emotional arousal, learning, memory, pleasure system.
- degeneration is linked to Parkinson’s disease
- high levels implicated in schizophrenia
norepinephrine
(NE)
- alertness and arousal, intense fear and pain, enhances attentions and memory.
serotonin
(5-HT)
- generally inhibitory; controls sleep/wakefulness/arousal; implicated in aggression, mood and pain.
glutamate
(Glu)
- always excitatory; NMD receptor implicated in learning/memory and neural plasticity
gamma-animobutyric acid
always inhibitory; found throughout the brain
endorphins
endogenous (internal) opioids; have analgesic effects, elevate mood.
- hero is exogenous (external) opioid
components of the CNS
brain and spinal cord
components of PNS
somatic and autonomic
what components make up the autonomic
sympathetic and parasympathetic
what parts are ascending tracts connected too
the brain
what parts are descending tracts connect to
the brain ====> muscles
afferent fibre
reflex
interneuron
(spinal cord)
efferent fibre
controls muscle
electrical stimulation of brain
(ESB)
stimulate brain region with electrode and ask patients what they experience