BIOPSYCHOLOGY Flashcards
the nervous system
specialised network of cells in the body, made up of the brain, spinal cord and nerves
body’s communication system that controls much of what your body does
function to collect, process and respond to information in the environment and to coordinate the working of different organs and cells
the nervous system list of functions
brain growth and development
sensations
perception
thought and emotions
learning and memory
movement, balance and coordination
sleep
nervous system regions
nervous system –> central –> brain + spinal cord
nervous system –> peripheral –> somatic + autonomic –> sympathetic + parasympathetic
central nervous system
BRAIN - collects info from sensory receptors and relays this to the muscles and glands of the body through the spinal cord
SPINAL CORD - carries signals to and from the brain + governs reflex actions that do not need to be processes by the brain
frontal lobe
responsible for consciousness and communication, memory and attention, motor control, problem solving and speech production
parietal lobe
responsible for sensory perception
occipital lobe
responsible for visual processing
temporal lobe
responsible for auditory processing, language comprehension and memory retrieval
brain stem
lower part of the brain, connected to spinal cord, responsible for regulating most of the body’s automatic functions and involuntary responses
cerebellum
involved in coordinating movement and balance, plays a role in cognitive functions like language and attention
brain structure
F P
T O
BS C
peripheral nervous system
contains all nerves outside the CNS and relays messages (nerve impulses) to and from the CNS
made up of somatic and autonomic nervous system
somatic nervous system
facilitates communication between the CNS and the environment or senses
mostly under conscious control and controls skeletal muscles
made up of sensory neurones that carry information to the spinal cord and brain and motor neurones that allow the brain to control movememnt
role is to carry sensory information from the environment to the brain and provide muscle responses via the motor pathways
autonomic nervous system
regulates involuntary physiological processes without conscious control
influences activity of most tissues and organ systems as it controls smooth muscles, internal organs and glands
important role in homoeostasis
only consists of motor pathways
made up of sympathetic and parasympathetic nervous systems - antagonistic (one active while the other relaxes)
sympathetic nervous system
typically involved in responses that prepare the body for fight or flight - adrenaline
impulses travel from the sympathetic nervous system to organs to help prepare for action when in a dangerous situation
e.g. increase heart rate, blood pressure and breathing rate
less important functions e.g. digestion, salivation, need to urinate are suppressed
parasympathetic nervous system
role is to relax the body and return us to normal resting state after fight or flight response
slows down heart and breathing rate, reduces blood pressure
‘rest and digest’ system
functions slowed down are started again e.g. digestion
cell body
contains nucleus and mitochondria
(DNA and provides energy)
dendrites
branches on cell body of each neurone that receives information from neighbouring neurones to trigger action potential
axon hillock
where nerve impulse is triggered from
axon
a tube-like structure
carries impulse away from cell body down the length of the neurone
myelin sheath
layers of fatty deposits that provide insulation for protection and help speed up the rate of message transmission
axon terminal
end of the axon
separated from other neurones by synapse
neurotransmitters
chemical messengers released from vesicles in terminal buttons and travel across the synapse and pass on the signal to the dendrites on the post-synaptic neurone
each has individual molecular structure with specific receptor sites that bind to dendrites of post-synaptic neurone
some are excitatory - cause increase in impulses
some are inhibitory - slow impulses
node of ranvier
gaps in the myelin sheath that force the impulse to ‘jump’ across the gaps along the axon, to help speed up the impulse
sensory neurones
transmit nerve impulses
found in receptors e.g. eyes, ears, tongue, skin
carry nerve impulses from the PNS to the CNS (muscles –> spinal cord / brain)
when nerve impulses reach the brain they are translated into ‘sensations’ e.g. vision, hearing, taste, touch
not all sensory neurones reach the brain - some stop at the spinal cord, allowing for quick reflex actions
unipolar - transmit messages in one direction
long dendrites, short axons, cell body coming off axon
relay neurones
found connecting sensory and motor neurones - allowing them to communicate
in brain, visual system and spinal cord
send and recieve messages within CNS
short dendrites and axons
have no myelin sheath - protected by spinal cord, short enough that do not need to be sped up
motor neurones
found in CNS but axons lie outside of CNS
control muscle movement and gland activity (effectors)
release neurotransmitters that bind to receptors on muscles to trigger a response when stimulated
leads to movement
short dendrites and long axons
reflex arcs
reflex actions terminate in the spinal cord to allow for a quicker response
receptors in the skin sense heat and nerve impulse transmits a message to the CNS via the PNS
relay neurones in the CNS carry the message to motor neurones
motor neurones send messages to the effectors creating a physical response e.g. moving away
action potential
change in electrical charge of a neurone that causes it to fire or not
messages sent through neurones electrically but passed across synapses chemically
when neurone is inactive
negatively charged
resting potential –> sodium and potassium ions are in lower amounts inside than outside the neurone
when neurone is stimulated
becomes positively charged
sodium ions move through cell membrane into neurone
generates an action potential which creates an electrical impulse that travels down the axon towards the end of the neurone
once action potential has reached its peak
channels allowing the flow of sodium close and the potassium ones open
positively charged potassium moves out of the neurone, making it return to its negative resting state - depolarisation
noradrenaline
excitatory
stress hormone produced within adrenal gland
quickens hormone, increases stroke volume, opens bronchioles etc.
part of fight or flight response to fear, panic or percieved threat
dopamine
excitatory
related to learning, emotions, cognitive functioning, movement control
enables us to see and take actions towards rewards
contributes to feelings of pleasure and satisfaction as part of reward system - plays role in addiction
serotonin
inhibitory
key role in maintaining mood balance
low levels linked to depression
role in appetite, emotions, motor, cognitive and autonomic functions
not known if has direct affects or overall role in coordinating nervous system
synaptic transmission
process of transmitting messages in the form of neurotransmission from neurone to neurone
cell’s electrical impulse / action potential is generated at the axon hillock, but once the impulse reaches the terminal buttons, it turns into a chemical message which cross the synaptic gap to the post-synaptic neurone
each neurone produces a certain neurotransmitter and when action potential reaches the terminal buttons, vesicles containing the neurotransmitter travel towards the membrane of the pre-synaptic neurone, which the casing of the vesicles fuse with, releasing the neurotransmitter into the synapse
neurotransmitters move from high to low concentration - pre- synaptic neurone –> post-synaptic neurone
neurotransmitter then picked up by receptors on post-synaptic neurone and binds to specific receptors –> receptor site activated
stimulation of post-synaptic neurone results in () of post-synaptic neurone
excitation (depolarisation) - electrical charge becomes more positive
inhibition (hyperpolarisation) - electrical charge becomes more negative
ion channels on post-synaptic membrane open to allow ions to flow in and out
neurotransmitters are either broken down by enzymes or reabsorbed by the pre-synaptic neurone (reuptake)
synapse
specialised gap between neurones, through which the electrical impulse from within the neurone is then transmitted chemically via neurotransmitters
summation
addition of excitatory and inhibitory influences on post-synaptic neurone
can recieve both positive/excitatory and negative/inhibitory
potentials are summed and net effect determines whether neurone fires or not
if ions flow in and trigger an action potential = excitation
if ions flow in but do not trigger an action potential = inhibition
endocrine system
regulates cell or organ activity and controls vital physiological processes
works alongside the nervous system
made up of network of glands across the body that secrete chemical messages called hormones that bind with specific receptors to regulate activity
information transmitted via blood vessels
each hormone produces different effects (behaviours)
each gland produces a different hormone - excite/stimulate a particular part of the body
gland
organ that makes one or more substances, and releases them into the bloodstream or into an opening to the inside or the outside of the body
hormone
chemical substances that act like messenger molecules
travel to other cells and organs and help to control how they work
through bloodstream
comparison of nervous and endocrine systems
NS works faster - neurones are interconnected but functions are more specific and short lived
ES is slower - signal transmission slower through bloodstream but acts more generally and lasts longer
hypothalamus
releases corticotropin-releasing hormone
connected to pituitary gland and is responsible for stimulating / controlling release of hormones from pituitary gland
control system which controls, regulates and drives the endocrine system
pituitary gland
anterior lobe secretes adrenocortical trophic hormone (ACTH) –> stimulates the adrenal cortex and release of cortisol during stress response
posterior lobe secretes oxytocin –> responsible for uterus contractions during childbirth
known as master gland as hormones released stimulate release of other hormones from other glands
receives signals from hypothalamus
pineal gland
releases melatonin –> responsible for important biological rhythms e.g. sleep-wake cycle
thyroid gland
releases thyroxine, responsible for regulating metabolism
adrenal gland
releases adrenaline and noradrenaline from adrenal medulla –> role in fight or flight
releases cortisol from the adrenal cortex, which stimulates the release of glucose to provide the body with energy while suppressing the immune system
ovaries
releases oestrogen –> controls regulation of female reproductive system, including the menstrual cycle and pregnancy
testes
releases androgens, including testosterone which is responsible for the development of male sex characteristics during puberty and muscle growth
fight or flight process
amygdala
hypothalamus
sympathetic nervous system
adrenal medulla
adrenaline + noradrenaline
fight or flight response
fight or flight response description
amygdala activated when someone enters a potentially stressful situation (responds to sensory input and connects it with emotions associated to the fight or flight response e.g. fear, anger)
if situation is deemed stressful/dangerous, a stress signal is sent to the hypothalamus
hypothalamus releases hormones to activate the sympathetic nervous system
if short-term response required, sympathomedullary pathway is activated
sympathetic nervous system triggers adrenal medulla which secretes adrenaline and noradrenaline into the bloodstream
causes physiological changes preparing the body for fight or flight
physiological changes for fight or flight
increased heart rate, blood flow and blood pressure
–> increase amount of blood supplied to the brain and skeletal muscles to enhance ability to fight or flee
increased breathing rate
–> increase oxygen intake
muscle tension
–> prepare for action, improve reaction time and speed
pupils dilate
–> vision becomes acute to focus attention on danger
sweating
–> temperature regulation
–> keep cool and maintain efficiency of the body so more likely to survive a dangerous event
diversion of blood away from skin and digestive system
–> lead to feelings of nausea or ‘butterflies’
–> to save energy to prioritise functions such as running
–> blood forced to major muscle groups
relaxation of bladder
–> reduction of non-essential functions to increase energy for essential functions
after fight or flight
once threat has passed
parasympathetic nervous system activated to return the body to its normal resting state
heart rate, blood pressure and breathing rate reduced
any functions previously slowed are started again
fight or flight weaknesses
human behaviour is not limited to just two responses
Gray also a freeze response, where we appraise situation to decide next course of action
- first response to avoid confrontation altogether
- weigh up options but can result in danger from slower action
behaviour not limited to fight and flight
beta bias may exist –> refers to theories that ignore or minimise sex differences + assume that male study results apply equally to females
Taylor found that females adopt a ‘tend and befriend’ response in dangerous situations - are more likely to try and protect offspring and form alliances rather than fight or flee (are physically weaker so running or fighting may be unsuccessful)
can be argued that fight or flight is a typically male response
early research conducted on men, so researchers assumed findings could be generalised to women
fight or flight response may not be adaptive in modern day
response would have been a useful survival mechanism for ancestors who faced physically life-threatening situations (predators), but modern life rarely requires such an intense biological response
stressors of modern day life can repeatedly activate the fight or flight response, which can have a negative consequence on health
stress
body’s biological response to an actual or percieved stressor
in evolutionary past, would have been essential to survival as enables the body to respond quickly to danger
today there is less danger in our environment but is still needed
sometimes responds to pressures and events not designed for and can lead to physiological and physical illness
acute stress response
SAM pathway
responds quickly to immediate danger and readies the body for fight or flight response
chronic stress response
hypothalamic-pituitary-adrenal pathway/axis (HPA)
responds to long-term constant stressors by keeping body alert
can also have harmful effects on body e.g. reducing immune system functioning
activated by hypothalamus when initial surge of adrenaline subsides
localisation of function
different areas of brain perform different functions for different parts of the body
holistic theory
prior to Broca and Wernicke
all parts of the brain are involved in all functions
contralaterally
each hemisphere controls and processes info from the opposite side of the body
cerebral cortex
outer layer, involved in higher cognitive functions
frontal lobe
personality characteristics, decision making and voluntary movement
parietal lobe
stimulus perception
touch, pressure, temperature and pain
temporal lobe
auditory processing, memory and language comprehensions
occipital lobe
visual info
motor cortex
back of frontal lobe on both hemispheres
voluntary movement on opposite side of the body
damage results in loss of control over fine movements