Ch. 4 - Bio Psych Key Terms Flashcards
epigenetics
changes in gene expression expression that are due to non-genetic influences
eugenics (francis galton)
the idea that the human gene pool would be improved if certain people didn’t have kids
heredity
the genetic transmission of characteristics from parents to offspring
heritability
an estimate of the genetic proportion of the variation in some specific trait
-within a particular POPULATION*
neurons
- basic unit of the nervous system
- operate through electrical impulses
- communicate with other neurons through chemical signals
what are the three types of neurons?
- sensory (afferent)
- motor (efferent)
- interneurons
action potential
- neural impulse that passes along the axon
- causes the release of chemicals from the terminal buttons
resting potential
- polarized state
- more NEGATIVE inside cell
- approx -70 mV
excitatory signals
- increase the likelihood that the neuron will fire
inhibitory signals
- decrease the likelihood that the neuron will fire
when do neurons generate an action potential?
if the excitatory input reaches a certain threshold (e.g., -55mV)
resting state (resting potential)
- neurons are polarized at about -70mV
- the inside of the cell is more negative than the outside
- there’s more potassium inside while there’s more sodium outside
all-or-none principle
a neuron fires with the same magnitude each time (it either does or doesn’t fire)
depolarization
- the neuron will depolarize when it reaches its excitatory threshold
- an action potential is generated
- sodium channels open and the charge in the membrane changes
- cell becomes positive inside bc of sodium influx
peak action potential and hyperpolarization
- at peak action potential sodium channels close and potassium channels open
- potassium leaves the cell
- outflow of potassium leads to temporary hyperpolarization
- potassium channels close and returns to polarized resting state
neurotransmitters
- chemical substances that carry signals from one neuron to another
- stored in vesicles inside terminal buttons
presynaptic membrane
membrane of the neuron that’s sending the signal
postsynaptic membrane
membrane of the neuron receiving the signal
glutamate
- primary EXCITATORY neurotransmitter
- GO signal
GABA
- primary inhibitory neurotransmitter
- STOP signal
dopamine
reward and motivation, voluntary movement
serotonin
mood, impulsiveness, hunger, sleep
acetylcholine
- movement; memory, cognition, sleep
- Key neurotransmitter in the autonomic nervous system