SAC 1 Flashcards
what is an action potential?
a neuron has a resting potential when not activated. negatively charged ions are inside the neuron and negatively charged ions are outside. all or nothing process
what are neurotransmitters
are a chemical substance produced by a neuron that carry a message to other neurons or cells in muscles, organs or other tissue. are around 50 types
role of neurotransmitters
- work by attaching or binding to receptor sites located on the dendrites of the post synaptic neuron
- they work to either excite the neuron to fire or inhibit the neuron from firing
excitatory neurotransmitters
increase to chance of an action potential firing and stimulate a response
two important excitatory neurotransmitters
glutamate: essential for memory forming and learning and excessive amounts can cause overexcitement of neurons leading to neural damage
dopamine: important for drive, motivation and motor movement
inhibitory neurotransmitters
restrict an action potential from firing therefore possibly inhibiting a response
two inhibitory neurotransmitters
GABA: when in low levels is linked to high anxiety and is essential for motor control and vision
serotonin: important for stabilising mood
CNS
central nervous system; made of brain and spinal cord. processes, organises and responds to stimuli
PNS
peripheral nervous system; made of somatic and autonomic. is a network of nerves that transmit info from muscles, glands and organs to CNS and back. Autonomic system has sympathetic and parasympathetic branches
role of axon + terminal buttons
axons transmit chemical impulses along the neuron in the form of an action potential. terminal buttons release the neurotransmitter
role of soma + myelin
soma is largest part of neuron, controls metabolism and matenience of the cell. Myelin is the white fatty coating that speeds up the message along the axon
parkinsons disease
is a neurodegenerative disease characterised by motor and non motor symptoms. effects the basal ganglia and the pre motor and primary motor cortex
cause of parkinsons + treatments
neurons in the substantia nigra degenerate meaning they do not produce dopamine sufficiently enough to support smooth motor movement. main treatment is L-DOPA which is a synthesised neurotransmitter
subtanstia nigra
basal ganglia
idiopathic
substantia nigra is a midbrain structure composed of nerve cells that produce dopamine and are associated with motor control
basal ganglia are clusters of nerve cells that regulate motor control
idiopathic means no known cause
symptoms of parkinsons
primary motor: tremors, bradykinesia, rigidity
secondary motor: reduced control of expressions, pain in limbs, swallowing problems
non-motor: embarrassment, anxiety, depression
agonist
drug that increases the uptake or release of a neurotransmitter. e.g dopamine agonist is levodopa cause it increases the chance of dopamine being taken up
antagonist
inhibits release of neurotransmitters or blocks the effect of them and makes receptor sites less likely to fire. e.g anti-psychotic drugs
alzheimers
an irreversible and progressive neurodegenerative disease that gradually kills brain cells and results in death. due to lack of acetylcholine
cause of Huntington’s and motor neuron disease
h = decrease in GABA m = imbalance of glutamate
what is stress
a state of mental or physical tension that occurs when an individual must adjust or adapt to an environment but they do not feel they have the capacity to do so
sources of stress and management
sources = family, friends, work, school, sports manage = exercise, sleep, mediation
stressor
the object or event that causes the feeling of stress
eustress
a positive psychological response to a stressor, characterised by positive psychological states that help the body perform at optimal level
distress
a negative psychological response to a stressor characterised by negative psychological states that impedes optimal performance
chronic
prolonged physiological arousal in response to a persistent stressor that negatively affects health
acute
brief but intense physiological arousal in response to an immediate perceived stressor that normally has no effect on health
sources of stress: daily pressures
frequently experienced stressors consisting of relatively minot events that require adjustments in behaviour e.g traffic
sources of stress: life events
stressors that consist of significant but relatively rare events that require substantial adjustments in behaviour within a relatively short time e.g marriage or job loss
sources of stress: acculturation
stress caused by attempting to psychologically and socially adapt to the demands and values of a foreign country
sources of stress: catastrophe
a sudden, unpredictable, uncontrollable intense event that causes large scale damage and suffering for a group of people. can cause PTSD. eg earthquake
what are stress responses
a set of physical and psychological which are automatically activated along with the sympathetic nervous system following the perception of a threat. they enable us to harness all our psychological and physiological resources to control the stressor
fight and flight
are mobilising responses to threats activated by the sympathetic nervous system. regardless of which is chosen the level of internal activity changes, bodily resources are mobilised and arousal is elevated. they are thought to be an adaptive response
freeze
an immobilising response to trauma, activated by parasympathetic system , it is our last attempt to survive after extreme trauma and it our most extreme defence strategy. it shuts down sympathetic system and directs all energy to organs and core and releases opiate receptors causing a numbing effect which means no fear or pain is felt and there might be no memory of the event. also thought to be adaptive as it help survival but if we get stuck in the freeze response we can’t return to homeostasis which will cause problems
role of cortisol
the body cannot maintain the intensity of the fight/flight response and the high levels of adrenaline and noradrenaline. when we are exposed to the stressor for a prolonged period of time the HPA axis is activated and through a process of steps releases corticosteroids (95% of this is cortisol) Cortisol’s main effect is to energise the body by increasing energy levels e.g blood sugar and has an anti-inflammatory effect. but if a person remains stressed with high levels of cortisol it can impair immune system functioning
Seley’s GAS
General adaptation syndrome is a biological/physiological response to stress that occurs regardless of the stressor encountered and is non-specific. has three stages alarm reaction (shock + countercheck), resistance and exhaustion.
stages of GAS model
- alarm reaction: shock is first, body goes into temporary state of shock, body temp and blood pressure drop, ability to deal with stressor is below normal. counter shock is next, sympathetic NS is activated = FFFs response, body is highly aroused.
- resistance: increased resistance to stress, cortisol release is sustained, all unnecessary psychological responses shut down, weakened immune system + social withdrawal
- exhaustion: if the stressor is not dealt with then resources are depleted and resistance to stress is low, immune system repressed and extreme fatigue, hypertension, migraines or ulcers
strengths + weaknesses of GAS model
strengths:
- provides rich info about physiological processes of stress
- based on imperial evidence
- connection between prolonged stress + disease
weaknesses:
- overemphasis on biological model (oversimplified)
- based on rats not humans
- role of emotion + cognition in stress response not considered
Lazarus + Folkman
is a transactional model of stress and coping. is the psychological/cognitive approach to stress and has two stages; primary appraisal and secondary appraisal
primary appraisal
“is this event something I have to deal with?”, “am I in trouble”, “is there any benefit now or in future”. ask these questions and the result will be either
1. irrelevant = no stress = end of appraisal
2. benign-positive = feeling ok = end of appraisal
3. stressful = causing stress = next stage, is this situation
a. harm/loss = damage already done
b. threat = possible additional harm in future
c. challenge = opportunity for positive outcome
select one and move on to secondary appraisal
secondary appraisal
once the situation is deemed stressful and what type of stress it is you ask “what, if anything can be down about this?” “how am I going to deal with this” then if
- coping resources are inadequate = stress
- coping resources are adequate = either
a. problem focused coping = logical direct approach to solving problem e.g asking for help
b. emotion focused coping = alleviate distress of problem e.g meditation
coping
a process involving constantly changing thoughts and behaviours so we can manage the internal and external demands of stressors we appraise as taking or exceeding resources
coping skills
learnt behaviours or techniques that help us solve problems or meet the demands of a stressor
coping strategy
the behavioural and psychological responses a person makes to a stressor that are intended to manage the stressor and reduce the psychological and physical stress related to it
coping effectiveness/ context specific effectiveness
the degree to which a coping strategy or combination of strategies is successful in alleviating stress
coping flexibility
the ability to stop an ineffective coping strategy or evaluate the coping process and implement an alternative effective coping strategy or adapt the coping process
benefits of physical exercise for stress
relives muscles of the tension caused by FF response and restores our body to a calmer more relaxed state and positively effects hormone levels, circulation and muscle tone + promotes good mood
approach strategies
target the stressor or the response to the stressor in practical ways. consist of behavioural or psychological changes designed to remove of diminish the nature of the stressor or how one thinks about it. these strategies help adapt to changes and demands from a stressor so that it becomes tolerable. most effective way of coping with stress and may be hard short term but is a lot better long term, includes; seeking support or goal setting
avoidance strategies
involve choosing response to stressor based either on trying to cognitively avoid or escape painful or threatening thought, feelings, memories or behaviours associated with the stressor. used when we feel we have no control over the situation. person does not directly conform the stressor and can withdraw from the exhibiting self destructive behaviour. can effect a person for life if used during childhood
