PSYCH 289 Unit 3 UPDATED ACTUAL
Questions and CORRECT Answers
key parts of a neuron - CORRECT ANSWER 1. cell membrane 2. soma 3. dendrites 4. axon 5.
myelin sheath (insulates axon) 6. terminal buttons/axon terminal (knobs at end of axon)
what are the 2 cells of the nervous system - CORRECT ANSWER neurons and glial cells
how do neurons convey info about strength or intensity of a stimulus - CORRECT
ANSWER stronger stimulus causes more action potentials
what is a synapse - CORRECT ANSWER the junction between 2 neurons
how many neurons/synapses in the brain? - CORRECT ANSWER 86 billion neurons 100 trillion
synapses
how are neural networks formed? - CORRECT ANSWER 1. axon & dendrites grow 2. synapses
form between neurons 3. hebb's rule: neurons that fire together:wire together 4. repeated activation (long
term potentiation) 5. network strengthens when frequently used 6. unused neurons pruned
what contribution did Donald Hebb make to our understanding of neural networks? - CORRECT
ANSWER 1. neurons work in networks - introduced CELL ASSEMBLIES 2. Hebbian learning
principle - repeated stimulation causes connections to change & strengthen 3. repeated neural activity &
synaptic changes are the basis of learning 4. his ideas are what LTP (long term potentiation) was based on
what is long term potentiation - CORRECT ANSWER repeated activations increases strength &
reliability of connections
what are glia/glial cells? - CORRECT ANSWER cells that support neurons and help signal the
nervous system provides the MYELIN COATING
, which cell produces cererospinal fluid? - CORRECT ANSWER glial cells collect water & nutrients
from the blood creating it
what IS cerbrospinal fluid? - CORRECT ANSWER the fluid that constantly circulates to help
cushion against injury while delivering nutrients and removing waste
how do we perceive the differences in intensity of stimulation? - CORRECT ANSWER fires faster
= feels stronger the greater the rate of action potential the greater the intensity of stimulus
what happens during a neural impulse? - CORRECT ANSWER 1. resting potential 2. graded
potential 3. action potential 4. absolute refractory period 5. synaptic transmission
what happens during the resting potential? - CORRECT ANSWER inactive - neuron polarized &
stable at negative charge - baseline voltage is -70mV
what happens during the graded potential? - CORRECT ANSWER neuron decides if there is
enough excitatory (+) or inhibitory (-) charge to trigger an action potential
what happens during an action potential? - CORRECT ANSWER thershold must be reached -55mV
-neuron fires Depolarization occurs: Na(sodium) enters > inside becomes positive - positive charge moves
down axon REpolorazation occurs: K(potassium) rushes out > inside becomes negative again
what is the absolute refractory period? - CORRECT ANSWER the time after the action potential
before another action potential can occur
what is the all or nothing law? why do they say it is binary? - CORRECT ANSWER a neuron either
fires or it doesn't 1 = neurons fire 0 = neurons don't fire
what happens during synaptic transmission - CORRECT ANSWER sythesis, transport & storage >
release > binding {splits} 1. inactivation/removal OR 2. reuptake
Questions and CORRECT Answers
key parts of a neuron - CORRECT ANSWER 1. cell membrane 2. soma 3. dendrites 4. axon 5.
myelin sheath (insulates axon) 6. terminal buttons/axon terminal (knobs at end of axon)
what are the 2 cells of the nervous system - CORRECT ANSWER neurons and glial cells
how do neurons convey info about strength or intensity of a stimulus - CORRECT
ANSWER stronger stimulus causes more action potentials
what is a synapse - CORRECT ANSWER the junction between 2 neurons
how many neurons/synapses in the brain? - CORRECT ANSWER 86 billion neurons 100 trillion
synapses
how are neural networks formed? - CORRECT ANSWER 1. axon & dendrites grow 2. synapses
form between neurons 3. hebb's rule: neurons that fire together:wire together 4. repeated activation (long
term potentiation) 5. network strengthens when frequently used 6. unused neurons pruned
what contribution did Donald Hebb make to our understanding of neural networks? - CORRECT
ANSWER 1. neurons work in networks - introduced CELL ASSEMBLIES 2. Hebbian learning
principle - repeated stimulation causes connections to change & strengthen 3. repeated neural activity &
synaptic changes are the basis of learning 4. his ideas are what LTP (long term potentiation) was based on
what is long term potentiation - CORRECT ANSWER repeated activations increases strength &
reliability of connections
what are glia/glial cells? - CORRECT ANSWER cells that support neurons and help signal the
nervous system provides the MYELIN COATING
, which cell produces cererospinal fluid? - CORRECT ANSWER glial cells collect water & nutrients
from the blood creating it
what IS cerbrospinal fluid? - CORRECT ANSWER the fluid that constantly circulates to help
cushion against injury while delivering nutrients and removing waste
how do we perceive the differences in intensity of stimulation? - CORRECT ANSWER fires faster
= feels stronger the greater the rate of action potential the greater the intensity of stimulus
what happens during a neural impulse? - CORRECT ANSWER 1. resting potential 2. graded
potential 3. action potential 4. absolute refractory period 5. synaptic transmission
what happens during the resting potential? - CORRECT ANSWER inactive - neuron polarized &
stable at negative charge - baseline voltage is -70mV
what happens during the graded potential? - CORRECT ANSWER neuron decides if there is
enough excitatory (+) or inhibitory (-) charge to trigger an action potential
what happens during an action potential? - CORRECT ANSWER thershold must be reached -55mV
-neuron fires Depolarization occurs: Na(sodium) enters > inside becomes positive - positive charge moves
down axon REpolorazation occurs: K(potassium) rushes out > inside becomes negative again
what is the absolute refractory period? - CORRECT ANSWER the time after the action potential
before another action potential can occur
what is the all or nothing law? why do they say it is binary? - CORRECT ANSWER a neuron either
fires or it doesn't 1 = neurons fire 0 = neurons don't fire
what happens during synaptic transmission - CORRECT ANSWER sythesis, transport & storage >
release > binding {splits} 1. inactivation/removal OR 2. reuptake
