chapter 4 Flashcards
twin studies and adoption studies
-study impact of genetic versus environmental influence
-monozygotic vs dizygotic twins
-monozygotic twins raised together versus apart
jim twins
-identical twins raised apart
-both suffer tension headaches
-nail biting
-smoke same cigs
-same car
genes x environment
-nature and nurture are inextricably intertwined
-impossible to separate generic from environment influence
-work together to make human behaviour
epigenetics
changes in gene expression due to non genetic (outer) infleunce
gene x environment case
low MAO-A gene +maltreatment = increased probability of crime
heredity
genetic transmission of characteristics from parents to offspring
heritability
estimate of genetic proportion of the variation in some specific trait (within population)
estimate of heritability
% of variation explained by genetic difference (social = 30%)
nervous system
body electrochemical communication circuitry
neuron
- cell of nervous system that is specialized to send and receive neural messages
- basic unit of nervous system
- operate though electrical impulse
- communicate with neurons through chemical signals
types of neurons
sensory = afferent
motor = efferent
interneurons
action potential
- electrical signal arising in a neuron axon
- neural impulse passes along the axon and causes release of chemicals from the terminal buttons
resting potential
-measure of electrical charge across a neural membrane when the neuron is not processing info
-polarized state (negative inside cell)
- -70mV
excitatory signal
-increase the likelihood that the neuron will firein
inhibitory signal
decrease likelihood that the neuron will fire
when do neurons generate action potential
-excitatory input (depolarization) reaches a threshold
- -55mV
all or none principle
-neuron fire with same magnitude each time (fires or does not fire)
-how frequently the neuron fires can vary
axon
branch of a neuron that is usually responsible for transmitting information to other neurons
dendrite
branch from the neural cell body that receives input from other neurons
myelin sheath
insulating material covering some axons
cell body
large central mass of a neuron contraining the nucleus
nodes of ranvier
uninsulated and highly enriched ion channels allowing them to participate in the exchange of ions required to regenerate action potential
resting state
-neurons are polarized at rest
-inside of cell more negative than outside
-more sodium (Na+) outside and K+ potassium inside
depolarization
-neuron reaches excitatory threshold, fully depolarized
-Na+ channels open and the charge across the membrane reverses
-more positive inside the cell due to influx Na+
peak action potential and hyperpolarization
-Na+ channels will close ahnd K+ channels open allowing K+ to leave
-outflowing of K+ leads to hyperpolarization whihc the cell cannot fire (refractory period)
-K+ channels close and cell returns to polarized restng state
neurotransmitters
-chemical messenger that communicates across a synapse
-carry signal from one neuron to another
-stored in vesicles in terminal buttons
GABA
primary inhibitory neurotransmitter
glutamate
primary excitatory neurotransmitter
serotonin
mood, impulsiveness, hunger, sleep
dopamine
reward, motivation, voluntary movement
acetylcholine
movement, memory, cognition, sleep
noepinephrine/epinephrine
stress response, fight vs flight
receptor
special channel in the membrane of a neuron that interacts with neurotransmitters released by other neurons
glia
nervous system cells that perform a variety of support functions including formation of blood brain barrier and myelin
synapse
point of communication between two neurons
reuptake
process in which molecules of neurotransmitters in the synaptic gap are returned to the axon terminal a from which they are released
reticular formation
collection of structures located along the midline of the brainstem that participate in mood arousal and sleep
brainstem
-part of the brain containing the midbrain, pons and medulla
-controls life sustaining functions of the autonomic nervous system
-breathing, digestion, heartbeat
cerebellum
structure attached to brainstem that participates in skilled mkovement and in humans, complex cognitive processing. cooridinated movement, balance
hypothalamus
-subcortical structure that participates in regulation of thirst, temperature, hunger, sexual behaviour, agression
-brain master regulatory structure -connect nervous system to endocrine system
-feeding, fighting, dlighting, functioning
thalamus
subcortical structure involved with processing of sensory information, states of arousal and learning/memory
-relay station
-all incoming info besides smell
tatiana and krista
craniopagus twins with brains connected by thalamic bridge
basal ganglia
collection of subcortical structures that participate in the control of movement
hippocampus
subcortical structure that participates in memory
-formation and storage of long term memory
amygdala
-role in processing fear
-associate things with emotional response
cerebral cortex
thin layer of neurons covering the outer surface of the cerebral hemispheres
corpus callosum
wide band of nerve fibres connecting right and left cerebral hemispheres
-bridge of axons
-allows info to flow between
frontal lobe
most forward
- location of primary motor cortex and areas responsible for some of the most complex cognitive processes
-planning, movement, motor cortex, prefrontal cortex
temporal lobe
lobe that curves around the side of each hemisphere
-primary auditory cortex
-hearing
parietal lobe
lies at the top of the brain
-somatosensory cortex
-sensory cortex
-touch
occipital lobe
back of the brain
-primary visual cortex
-vision
peripheral nervous system (PNS)
nerves exiting CNS that carry sensory and motor information to and from the rest of the body
-somatic NS
-autonomic NS
-transmits info to CNS, responds to messages from CNS
- perform behaviours
-make body adjust
sympathetic nervous system
coordinates arousal
fight or flight
prepare body for action
parasympathetic nervous system
rest, repair and energy storage
- returns body to normal state/rest/ digest
-chronic activation leads to health issues
central nervous system (CNS)
brain and spinal cord
endocrine system
-responsible for release of hormones into the bloodstream
-works with nervous sytem to regulate psychological activity
-nervous system uses electrochemical signals
-endocrine uses hormones
hormones
chemical substance released into blood stream by endocrine glands to tissues
-slow communication
-widespread and long lasting effects
cingulate cortex
forward part participates in decision making and emotion
-rear works on memory and visual processing
- subcortical structure above corpus callosum
executive function
basic and higher level cognitive processes that enable self-regulationand cgntivie control of behaviour (planning, decision making and goal pursuit)
neurogenesis
generation of new neruons
nucleus accumbens
reward and addiction subcortical structure
orbitofrontal cortex
right behind the eyes that participates in impulse control
prefrontal cortex
most forward part of the frontal lobe of the cerebral cortex
coordinated systems
neural activation means hypothalamus secrete releasing factor
-releasing factor causes pituitary gland to release hormone specific to factor
-hormone travels through blood to target sites through body
HPA axis
-release cortisol into blood by adrenal glands
-slow developing effects
-effects of chronic stress
-suppression of immune system
diencephalon
-interbrain
(epithalamus, thalamus, subthalamus, hypothalamus)
phineas gage
-rod through skull
-injury to frontal lobes
-modern image allowed scientists to recreate path of gag tamping iron through brain
-friends described as a changed man
-angry outbursts and unreliability
patient george
-stroke in left thalamus
-mingling of sense
-synethesia
-sensory emotional experience hearing james bond
-emotional arousal intense
-sensory and motor areas support extracorpeal experience
patient HM
-anterograde and retrograde amneisa
-remove hippocampus and anygdala to control seizures
-seizures decrease
-no longer form new memories
-recall childhood but not recent
-cant remember facts or faces
agonist
-enhance the action of neurotransmitter
-bind to receptors and produce a response mimics effects
endogenous neurotransmitters
–increase release or block reuptake
antagonist
-drugs that inhibit the actions of neurotransmitters
-block release
-destroy in synapse
-mimicking and biding
neuroplasticity
-ability of neurons to change in structure and function throughout the life span
autonomic nervous system
-efferent and afferent paths between CNS and smooth muscles/glands
-divison of the peripheral nervous system that directs the activity of glands organs and smooth msucles
-internal environment
-autonomic response involves involuntary body functions
somatic nervous system
-part of perpheral nervous system that brings sensory infomation tot eh CNS and transmits commands to the nucleus
- external environement
-motor neurons responsbile for sending signals from CNS to skeletal muscles
-voluntary motor control
->efferent path
-conscious perception –> afferent path
