2: bio foundations of behavior Flashcards
neurone (neurone/nerve cell)
electrically excitable ell that processes and transmits info through electrical/chemical signals
core components of the brain, spinal cord (CNS), ganglia (PNS)
sensory neuron
detects changes in external/internal environment and sends info to CNS
touch, sound, light, etc.
PNS
.
CNS
.spinal cord and brain
afferent neurons
carry messages inward toward CNS
motor neuron
in CNS, controls contraction of muscles (from CNS signals)
efferent neurons
carry messages outward from CNS
interneuron
located entirely within CNS
connects neurons within same region of brain/spinal cord in neural networks
bipolar neuron
sensory systems
vision/hearing
unipolar neuron
somatosensory systems
touch/pain etc.
soma`
cell body, contains nucleus (keeps cell alive/functional)
dendrite
attached to soma
receives info from terminal buttons of other neurons
terminal buttons
end of the neuron, sends info to dendrites of other neurons (synapses)
axon (nerve fiber)
long, thin, cylindrical structure
sends info from soma to terminal buttons
action potential
.
glia
surrounds neurons and keep them in place
provide nourishment/oxygen to cells
insulate neurons
destroy pathogens/remove dead neurons
protect from harmful substances
form the myelin sheath
can send signals that regulate strength of connections between neurons
release chemicals that increase reactivity of neurons
form networks
may modulate the activity level o neurons nearby
myelin
white fatty substance
makes up some types of glial cells
glial cells wrap around axon to provide insulating myelin sheath
white matter
myelinated axons traveling (within brain or to/from body)
gray matter
cell bodies + dendrites + unmyelinated axons
action potential
electrical signal communication within the neuron
sent from cell body to terminal buttons telling them to release neurotransmitters
fundamental info carrier of the nervous system
will always be same size and speed
resting potential
membrane potential of a neuron when it is not being altered by excitatory/inhibitory postsynaptic potentials
threshold of excitation
value of the membrane potential that must be riches to produce an action potential
Depolarization
reduction of membrane potential from normal resting potential
refractory period
time after an action potential where neuron’s cell membrane is unprepared for next action potential
neuron fire
when neuron produces action potential
propagation
spread of action potential down axon caused by successive changes in electrical charge alone length of axon’s membrane
all-or-none law
action potential is always same speed/strength
synapse
junction between terminal button and membrane of another neuron
neurotransmitter
chemical released by terminal button
has excitatory/inhibitory effect on other neurons
presynaptic neuron
sends message
post synaptic neuron
receives message
presynaptic membrane
membrane of terminal button that lies adjacent to postsynaptic membrane
postsynaptic membrane
opposite to the terminal buttons (which receive info)
synaptic cleft
space between pre/post synaptic membrane
synaptic vesicle
small, hollow, beadlike structure
interminal buttons
contains molecules of a neurotransmitter
Dopamine (DA)
Influences movement, motivation, emotion, learning, attention
Norepinephrine (NE)
Helps control arousal level; influences wakefulness, learning, + memory
Glutamate
Major excitatory transmitter in the brain, role in learning and memory
Gamma-amino butyric acid (GABA)
Most widely distributed inhibitory transmitter in CNE
Serotonin (5HT - 5-hydroxy-tryptamine)
Involved in sleep, mood, hunger, and arousal
Acetylcholine (ACh)
Realized at many synapses, makes muscle fibers contract. Involved in learning, memory
Postsynaptic potential
Produced by release of neurotransmitter at synapse
Alteration of the membrane potential of a postsynaptic neuron
depolarizing (excitatory)
Hyper-polarizing (inhibitory)
Excitatory postsynaptic potential (EPSP)
Excitatory depolarization of the postsynaptic membrane of a synapse
Caused by liberation of a neurotransmitter by terminal button
Inhibitory postsynaptic potential (IPSP)
Inhibitory hyper-polarization of the postsynaptic membrane of a synapse caused by liberation of a neurotransmitter by the terminal button
Neural integration
Process where inhibitory and excitatory postsynaptic potentials summate and control the rate of firing
Inhibitory = IPSPs diminish the size of EPSPs and prevent firing
Excitatory = EPSPs summate as they travel towards axon and the axon fires
Reuptake
Re entry of a neurotransmitter just released by a terminal button back through its membrane (terminating the postsynaptic potential)
Enzymatic deactivation
Destruction of a neurotransmitter by an enzyme after its release (ex: acetylcholine by acetylcholinesterase)
Agonists
Drugs that enhance a neurotransmitter’s activity
Antagonists
Drugs that impede the activity of a neurotransmitter
