lecture 2 Flashcards
nervous system is composed of these 2 major cells:
neurons and gilal cells
how many neurons in human brain?
100 billion
how many synapses in human brain?
100 trillion
what are synapses?
the gap where two neurons meet
what do glial cells do?
provide support for neurons by supplying nourishment to neurons, remove waste product, and insulation around axons
basic parts of the neuron: (6)
soma, nucleus, dendrites, axon, terminal buttons, synapse (or synaptic cleft)
soma and what does it contain?
cell body, and contains the nucleus and organelles of the neuron
dendrites:
part of neuron that receives info from other neurons
axon:
long thin fiber that transmits signal from the soma to other neurons, muscles or glands. most covered in myelin sheath
terminal buttons:
small knobs that secrete neurotransmitters which enters the synapse between two neurons to send info to the dendrite of the neighboring neuron
principal neurons:
sends signals to another brain region
interneurons:
receives and sends signals within a local region in the nervous system
motor neurons
has dendrites that extend it over a long distance to send signals to muscles
sensory neurons:
receive signals from sensory organs
how do neurons communicate?
by producing electrical energy to signal terminal buttons to release neurotransmitters into the synapse
excitatory post synaptic potentials is a:
positive voltage shift that increases the likelihood the next neuron will fire an action potential
inhibitory post synaptic potentials is a:
negative voltage shift that decreases the likelihood the next neuron will fire an action potential
GABA produces ______ effects on neurons
inhibitory
glumamate produces ____ effects on neurons
excitatory
agonists:
chemicals that mimic the action of a neurotransmitter
antagonists are:
chemicals that oppose the action of a neurotransmitter
cell assembly:
interconnected neurons representing a perception of concept, which could be strengthened by experience
long term potentiation:
cellular mechanism for strengthening connection between neurons, increasing EPSP and probability of action potential
long term potentiation requires 2 synaptic events:
- pre synaptic signal
- increase in the potential of the post synaptic cell
long term depression:
decrease in synaptic efficiency
where does long term potentiation and long term depression occur
hippocampus, amygdala, striatum and elsewhere in cerebral cortex
hippocampus function:
consolidation of memory
amygdala function:
emotions, fear, aggression
olfactory bulb:
processes sense of smell
cingulate gyrus function:
emotions and behaviors
