cns
major division of the nervous system that contains all the nerves the brain and the spinal cord. it transmits and receives messages from the pns.
brain
organises, integrates and interprets information from the rest of the body and generates responses. processes sensory information from the soinal cords and decides motor responses to send back through the spinal cord.
spinal cord
receives sensory messages from the pns and send this to the brain, and receives motor messages from the brain to send to the pns. it is lined with interneurons.
pns
major division of the nervous system that consists of all muscles, organs and glands outside the cns. transmits sensory messages towards the cns and transmits motor messages from the brain outward to the rest of the bidt
motor/efferent neurons
carry motor infomation from cns to skeletal muscles (effector site) to enable voluntary movement.
sensory/afferent neurons
carry sensory information from the internal and external environment to the cns.
somatic nervous system
division of the pns and transmits sensory messages from the sensory receptors to the cns, and transmits motor messages from the cns to skeletal muscles to enable voluntary movement.
autonomic nervous system
division of the pns that involves involuntary activity of visceral muscles, organs and glands.
sympathetic nervous system
branch of the autonomic nervous system, alters the activity of muscles, organs and glands to prepare our body for increased activity during times of arousal.
fight-flight-freeze response
an involuntary action which arouses and energises the body to deal with an immediate threat, and results in a state of physiological readiness. fight or flight response is a sympathetic response where you either flee a stressful situation or choose to fight it, and your body will prepare you for both depending on the decision made. the freeze response is a part of the parasympathetic ns, and involves conserving energy. it is triggered by both physical and psychological threats.
parasympathetic nervous system
a branch of the autonomic system that helps maintain homeostasis and physically calms the body after high arousal. responsible for sleep, eating and reproduction.
homeostasis
a inner equilibrium within the body, where internal systems are balanced.
enteric nervous system
the largest division of the autonomic nervous system, embedded in the walls of the gastrointestinal tract. functions independently of the cns.
name 5 functions of the enteric nervous system
detects physiological condition of the gastrointestinal tract
control muscle contractions
regulates nutrients and gastric acid secretions
changes local bloodflow to where needed
maintains gut chemistry
conscious response
always requires the brain, associated with voluntary actions of the somatic nervous system.
unconscious response
helps perform involuntary actions where we don't need to even be aware of the stimuli for a decision to be made.
autonomic functioning
where a bodily function can occur without a conscious decision or voluntary movement being made.
spinal reflexes
a somatic faster reflex response that aids survival and avoids tissue damage in dangerous situation.
neurons (pre and postsynaptic)
allow neurotransmitters to travel from the presynaptic neuron's axon terminals to the post synaptic neuron's dendrites across the synapse.
synapse
a gap between the pre and post synaptic neurons where neurotransmitters are carried, and where stronger connections are made when a new skill is learnt
axon terminals
where neurotransmitters are released from synaptic vesicles.
receptor sites
where neurotransmitters are received
neurotransmitters
chemical messengers that cross the synaptic gap to deliver a neurological message.
glutamate
the main excitatory neurotransmitter in the cns, that helps with memory and learning. acts on the ampa, nmda receptors, and increases activity level of cortical neurons.
gaba
an inhibitory neuromotransmitter that makes the neuron less likely to fire. gaba helps maintain homeostasis.
neuromodulators
chemicals that can enhance the effects of neurotransmitters, and change the reactivity of receptors to another type of neurotransmitter (to increase excitatory or inhibitory response). they can affect a large number of neurons at the same time
serotonin
a hormone/neuromodulator that has a wide range of effects, but mainly inhibitory to help balance mood, appetite, emotional processing, sleep onset, appetite and pain perception. 90% of serotonin is found in the gut
dopamine
a hormone/neuromodulator which has an excitatory or inhibitory effect depending on the type of receptors present. it is produced in the substantia nigra, carries messages and allows smooth coordinated function of the body's muscles and movements.
long-term potentiation (ltp)
an activity dependent process, the long lasting strengthening of synaptic connections after a high frequency of stimualtion. occurs when two neurons are activated simultaneously. which is the fundamental mechanism of memory formation that leads to learning
long-term depression (ltd)
long lasting weakening of the effiiciency of synaptic connections over time when synaptic stimulation is reduced, and there is low co-activation of neurons
sprouting
the growth of nerve endings on axon terminals or dendrites to allow neurons to make new connections
re-routing
occurs when new connections are made between neurons to create alternative neural pathways.
pruning
the elimination of weak, unused dendrites. synapses that are frequently used are strengthened, those that aren't decay and dissapear.
neural plasticity
ability of the brain's neural structure to be changed by experience
synaptic plasticity
ability of synapses to change over time, through formation of new synaptic connections that strengthen the synapse or lower the frequency of use which weakens the synapse.
research question
based on the topic that can be investigated and tested.
aim
statement regarding the topic that is being investigated or tested. always starts with ‘to investigate’
variable
any factor that can change in amount or type over time
controlled variable
must be held constant to remove potential effects on the dependent variables.
dependent variable
variable we measure
independent variable
variable that is manipulated, changed or varied in some way to measure the effect on the dv
hypothesis formula
POP, 1/2 IV , D, DV, 1/2IV
population
entire group of people researchers are interested in
sample
a smaller group of people taken from the population that participate in th study
population sampling
how the sample is chosen from the population
random sampling
every member of the population has an equal chance of being selected to participate.
stratified sampling
ensures each subgroup of a characteristic is represented in the sample in the same proportions as it is in the population
stress
psychological and physical response to a source stressor that challenges a person’s ability to cope.
stressor
source of tension that challenges a person’s ability to cope.
internal stressor
originate within the individual which can be psychological or biological or physiological.
external stressors
originate outside the individual, including cultural, social or physical environment
acute stress
immediate response to a perceived stressor, which can have negative or positive effects depending on its intensity. often caused by daily demands, and pressures but disappears after short periods of time.
chronic stress
when stressor continues for a prolonged period of time, which are often less intense than acute stressors, and can be harmful to health and wellbeing.
adreno-medullary system
activates sympathetic fight-flight response
what are the three stress hormones?
adrenaline, noradrenaline and cortisol
cortisol
is released minutes after adrenaline and noradrenaline. it energises the body by increasing blood sugar and enhancing metabolism. also increases the availability of substances that repair tissue, increasing alertness.
HPA axis
plays a part in the gba
disadvantages of cortisol
when cortisol remains in the bloodstream for an extended amount of time, immune system functioning and cognitive performance is impaired, weight gain occurs, likelihood of physical and mental problems increases as does risk for heart attack and stroke.
detail the steps of the fight-flight-freeze response in regards to hormone release.
hypothalamus detects heightened arousal → sympathetic nervous system activated →adrenal medulla releases adrenaline and noradrenaline →increased energy and heightened arousal.
gut brain axis (gba)
bi-directional, multi-faceted communication link between cns and the ens. there are several pathways linking ens and the brain, but mainly the vagus nerve.
gut microbiota
all microorganisms present in the digestive tract, including bacteria, viruses and fungi. they influence digestion and produce serotonin and other neurotransmitters within the gut. disruption of gut microbiota can impact psychological microbiota.
enterotype
unique combination of gut microbiota in each individual
microbiome
the collection of all the microorganisms and viruses that live in a given environment, including the human body or part of the body.
general adaptation syndrome (gas)
a non-specific three stage physiological response to stress that occurs regardless of the encountered stressor. it is a generalised reponse same in all people regardless of the stressor.
what are the three stages of gas
alarm reaction (shock, countershock) 2. resistance 3. exhaustion.
shock response (gas)
body acts as injured and reacts poorly to stressor. parasympathetic ns is dominant. blood pressure and body temperature drop, and there is a temporary loss of muscle tone.
countershock response (gas)
better response to stressor. adrenaline, noradrenaline then cortisol is released. sympathetic ns and fff are dominant
resistance phase (gas)
body’s ability to deal with a stressor rises above normal. ongoing release of cortisol. resistance to inital stressor increases and resistance to new stressors decline, people often get sick during this phase.
exhaustion phase (gas)
body cannot cope with the stressor and its resistance to coping with stress drops below normal. resources are depleted.
2 strengths of gas
predictable physiological pattern which can be measured, suggests a link with prolonged stress and diseases
2 weaknesses of gas
performed on animals, doesn’t focus on psychological response.
lazarus and folkman’s transactional model of stress
propses that stress involves a transaction where stress responses depend on the appraisal of the stressor and ability to cope with it.
transaction (l&f)
an encounter with an individual and their environment.
primary appraisal (l&f)
significance of situation is evaluated as irrelevant, benign positive or stressful. if deemed stressful, then evaluated as a harm/loss, threat or challenge.
secondary appraisal (l&f)
where options for dealing with the stressful situation and strategies which will be used are evaluated as if coping resources are adequate or inadequate.
4 strengths of l&f
focuses on psychological determinants, emphasises individuality of stress, stress as an environmental interaction, stressor chan change over time
4 weaknesses of l&f
overlooks physiological response, difficult to test due to subjectivity, we can experience stress without the model, primary and secondary appraisal are not mutually exclusive.
context specific effectiveness
match between coping strategy and stressful situation (context), and is more likely to occur in those with high coping flexibility
coping flexibility
ability to modify something when coping strategy is ineffective.
approach strategy
behaviours that attempt to decrease stress by dealing with the problem
avoidance strategy
behaviours that attempt to decrease stress by not dealing with the problem. where the individual aims to have no control over the stressor, for psychological relief
ethics
protect the rights and welfare of participants, and ensure that the research study is designed in ethically appropriate ways in accordance to the ethical guidelines
what are the 5 ethics guidelines
beneficence, respect of persons, integrity, non-maleficence, justice.
beneficence
where potential research outcomes are maximised and risks of harm are minimised.
respect for persons
properly regard welfare, rights, beliefs and customs of individuals involved in study
integrity
researcher’s responsibility to conduct research and report results in an honest ethical manner
justice
ensure a fair distribution of benefits and burdens with the population of research interest
non-maleficence
avoiding causing harm. harm shouldn’t be disproportianate to the benefits from any position of action
what are the 6 participant rights
voluntary participation, informed consent, confidentiality, deception, withdrawal rights, debriefing
confidentiality
right to privacy, participants must not be identified in any way in the results
voluntary participation
participants have the right to refuse to take part in the study, no pressure or deception to ensure participants take part
withdrawal rights
participants have the ability to leave the study at any stage regardless of possible effects on the results. they also have the ability to remove their results at the conclusion of the study.
informed consent
participants must be told about the true nature of the study, their participant rights and any potential risks. they must give written agreement to take part. minors or those who aren’t of sound mind must have written agreement by their guardians
deception
when participants are not told of the true nature of the study.
when is deception warranted?
if it is approved by the ethics committee, so that the value of research outweighs the need for deception and appropriate debriefing and counselling procedures are in place to ensure that there is no lasting psychological or physiological harm to participants.
debriefing
takes place at the conclusion of the experiment, and helps ensure that the participant understands the aim, results and conclusions. support/counselling is also provided to ensure no lasting harm has been created. debriefing is especially essential with studies involving deception
dendrites
fulfill their role in neural transmission before axon terminals, and receive neurotransmitters on their receptors across the synaptic gap.
describe the 8 steps of the spinal reflex
Receptor cells detect stimuli
Sensory neurons receive messages
Transmission along sensory (afferent) pathway to spinal cord
Sensory message received in the spinal cord.
Interneuron relays message to motor neuron directly
Transmission along motor efferent pathway
Motor message received in finger
Spinal reflex involving withdrawal initiated without brain involvement
list 3 physiological symptoms of stress
heart palpatations, decline in immune system functioning, fatigue
list 3 psychological symptoms of stress
anxiety, lack of motivation, irritable.