lecture 3 - neurons Flashcards
3 types of neurons
afferent
interneurons
efferent
afferent neurons
take signs from body or environment to the brain
interneurons
neurons between neurons that integrate information
most numorous
efferent
take signals from the brain to the rest of the body
parts of the neuron
dendrites
soma
myelin sheath
axon
synapse
axon terminal
action potential
electrical signal that is sent down the axon
communication within neuron = electrical
soma
- middle part of neuron
- makes protein to repair different parts of the cell
- makes chemicals to send to other neurons
- passes down message to axon terminal
dendrites
- detect chemical messages
- other neurons will connect to them
axon
passageway that send messages
axon terminal
end of the axons
- sends neurotransmitters
synapse
- junction between neurons
- where neurotransmitters are released
myelin sheath
wrapped around axons to protect them and help increase action potential speed and make strong electrical messages
depolarized
neurons become depolarized during an action potential when positive particles flow into the axon
neuron at rest
is polarized
has a negative pole inside
positive pole outside
functions of gial cells
- scaffolding: gives structure
- nutrients and oxygen: gial bring nutrients to neurons
- insulators: provide myelin sheath
- house keepers: clean waste made by neurons
presynaptic side
neuron that is sending a message on to the next one
postsynaptic side
neuron that is receiving messages from another one
how synapse works
= chemical messages
presynaptic releases neurotransmitters into the synaptic gap and get recepted by receptors that send messages to postsynaptic neurons, which then becomes the pre as the cycle continues
vesicles
little packets of neurotransmitters
receptors
- joining points
- lock and key principle
- only accept certain shapes
- neurontransmitters will bind to the receptors if they are the right shape
Reuptake
unused neurotransmitter is reabsorbed by pre-synaptic neuron
without it, neurotransmitter would just keep activating the postsynaptic neuron
excitatory neurotransmissions
transmitter is sent out that excites the next neuron (accelerates it0
inhibitory
makes sure that the next neuron is less likely to send an action potential
stopper/braker
types of neurotransmitters
- glutamate
- GABA
- dopamine
- endorphines
- serotonine
glutamate
- implicated with memory and learning
- accelerates
GABA
- inhibitor
- strongly implicated in learning and memory
dopamine
- excites and inhibits
- different types of receptors
- receptors determine what it willl do
- dopamine rewards learning and motivates
endorphins
- inhibits pain signals
serotonin
- excite or inhibit
- implicated in well-being and mood
peripheral nervous system
- somatic
- automatic –(sympathetic & parasympathetic)
Somatic nervous system
- voluntary motions
- touch and pain info
autonomic nervous system
- involuntary movements
- includes sympathetic and parasympathetic
sympathetic nervous system
- prepares for action
parasympathetic
- rest and digest
central nervous system
- command center
- brain and spinal cord
cerebral cortex
outer layer of brain
longitudinal fissure
separates left and right hemisphere
sulci
grooves all over the brain (inside folds and wrinkles)
gyri
ridges on brain (upper part of folds and wrinkles)
corpus callosum
- means hard body
lets right and left hemispheres communicate w each-other
brain stem
- pons: sleep cycle
-medulla: automatic system - midbrain: sends sensory to cortex
cerebellum
- little brain
- controls movement, language, and timing
4 lobes of the brain
- frontal
- pariental
- occipital
- temporal
frontal lobe
- planning
- motor cortex
- language
parietal lobe
-somatosensory (touch) cortex
- integrates sensory info
occipital lobe
vision
temporal lobe
- hearing
- vision
- language
phineas gage
- phineas gage
- pole went through his frontal lobe and changed his behaviours
- he became more impulsive
problems with studying brain damage
- not reliable because can vary from person to person
- global damage: damage can affect more than one are
electrical stimulation
- dr. penfield
- stimulates certain parts of the brain to find the problem area (where seizures were happening)
fMRI
- measures blood flow
- pro: good spatial resolution
- con: time resolution
- cant see fluctuation between miliseconds
EEG
- a bunch of sensors measure fluctuations
- pro: time can see evry fluctuation per millisecond
- con: poor spatial resolution
- much less expensive than fMRI
