Sac 1 - Nervous system/ stress Flashcards
What does the central nervous system comprise of?
Brain and spinal cord
What does the peripheral nervous system consist of?
Autonomic and somatic, muscles, organs and glands
How many neurons in your brain?
100 billion
What does the brain regulate?
- vital body functions
- breathing
- heart rate
- digestion
What is the spinal cord?
A cable-like column of nerve fibres that extend from the base of the brain to the lower back and is encased by a series of bones called vertebrae
What information is passed through the spinal cord?
- passes sensory information on from the PNS to the brain
- passes motor information from the brain to the PNS
(SAME) - Inside the spinal cord
- sensory/afferent messages towards the brain (afferent tracks)
- motor/efferent messages away from the brain (efferent tracks)
PNS - Receive
Sensory receptor sites (skin), sight, taste, hearing, internal muscles, organs and glands
PNS - Respond
Effector sites (muscles), movement, withdraw, pursue, pain
Somatic nervous system
- initiates skeletal movement
- it controls all voluntary movement and responses
- carries sensory information to the CNS (neural pathways are afferent/ towards)
- carries motor information from the CNS (neural pathways are efferent/away from)
Autonomic nervous system
- a network of neurons that carries neural messages between the CNS and the heart, lungs and other organs and glands
- regulates the functioning of internal organs and glands automatically
Which system activates the fight-flight-freeze response?
Sympathetic nervous system
Where is the substantia nigra located?
Midbrain
Sympathetic nervous system
A division of the ANS that activates the internal muscles, organs and glands to prepare the body for vigorous activity, or to deal with a stressful or threatening situation
- increases the activity of most of the body’s muscles, organs and glands (stimulates)
- fight- flight- freeze response
- triggered by a stressor
- heart rate and breathing rate increases
- adrenaline is released into the bloodstream
What is the fight-flight-freeze response?
Initiated by the sympathetic nervous system and prepares the body to confront a stressful situation to optimise the chance of survival
What does fight, flight and freeze mean?
- Stay and attack
- Run
- Go unnoticed or detected
What is the name of the state when the body is maintaining equilibrium?
Homeostasis
Spinal reflex
An automatic response that is initiated by neurons in the spinal cord, instead of the brain
Where are interneurons found?
In the CNS
Interneuron
A neuron that can communicate between sensory and motor neurons
Dendrite
Receives incoming neural messages
Soma
The body of the neuron, contains the nucleus with the genetic material for the neuron
Axon
The pathway the neural message passes down
Myelin sheath
Fatty tissue that encases the the axon to aid in speed of transmission
Axon terminals
Exit pathways for neural messages to make their way to the next neuron
Terminal buttons/ Synaptic knobs
Releases a chemical substance known as neurotransmitters to a receiving neuron for communication purposes
Action potential/ Neural impulse
An electrical impulse initiated by the soma and travels along the axon towards the axon terminals
Neurotransmitter
A chemical substance, typically made up of small molecules
How many neurotransmitters are there?
Around 50 types
What two basic effects do neurotransmitters have on the post-synaptic neuron?
- to excite the neuron to fire
- to inhibit the neuron from firing
Excitatory neurotransmitters
Those that cause a neuron to fire and hence stimulate a response
Most prominent excitatory neurotransmitter
Glutamate
Glutamate
An excitatory neurotransmitter essential for memory formation and learning
Dopamine
An excitatory neurotransmitter important for drive, motivation and motor movement. Without it, individuals can suffer from depression
Inhibitory neurotransmitters
Those that stop a neuron from firing and hence inhibit a response
Most prominent inhibitory neurotransmitter
(GABA) gamma aminobutyric acid
Neurotransmitter interruption
Can occur from an imbalance or deficiency in a particular type of neurotransmitter.
Causes of neurotransmitter interruption
- alcohol/drugs
- diet/nutrition
- stress
- genetics
Side effects of neurotransmitter interruption
- mental health disorder
- addiction
- immobility
- weight loss/gain
Serotonin
An inhibitory neurotransmitter that involves stabilising mood. Without it individuals suffer emotional disturbances that can result in schizophrenia
Parkinson’s disease
A neurodegenerative disorder characterised by chronic and progressive changes in the brain due to the malfunction and deterioration to neurons which leads to impairment in movement
(GABA) gamma aminobutyric acid
Its overall effects are to calm or slow neural transmission and therefore the bodies response
Stressor
the event/thing that causes stress
Stress
a state or physiological or psychological tension
Stress reaction
the physiological and psychological result of stress
Stress definition
an automatic psychological and physical tension (arousal) a person feels in response to change in the internal or external environment which challenges a person’s ability to cope
Stress reactions (physiological)
- skin rashes
- headaches
- cold/flu
- heart palpitations
- heart attack
- stomach ulcers
Stress reactions (psychological)
- behavioural
- emotional
- cognitive
Behavioural: - changes to eating habits - changes to sleep Emotional: - irritability - aggression Cognitive: - decreased concentration - memory impairment
Relationship between stress and illness
- stress does not cause illness, however the severity and length of the stress can lead to illness being more likely
- people who are stressed are more susceptible to a range of health concerns
- a psychosomatic illness is one that has physiological symptoms due to psychological factors
Acute stress
the body’s immediate and short-term response to stress
Chronic stress
the body’s response to prolonged stress; leads to exhaustion and health problems
Eutress
a positive psychological response to a stressor, this can include feelings of enthusiasm and motivation, and may occur due to events like a party or a roller-coaster
Distress
a negative psychological response to a stressor, this can include feelings of anger and anxiety, and may occur due to events such as relationship issues or losing an important sporting game, long term distress can have serious negative consequences on health
Flight - fight - freeze response (stress)
- it is activated when the body is confronted with a stressor and chooses to either confront (fight), run (flee), or remain motionless (freeze)
- any adaptive response that gives the body all necessary resources to maximise survival
What if stress is prolonged?
- our fight - flight - freeze response is the initial reaction which releases adrenaline, long term this can be harmful
- the stress hormone known as cortisol is vital for many reasons, including maintaining non-viral functions such as digestion, mood and growth
- it needs to be signaled that there is a threat by the amygdala in the brain, which triggers the HPA axis to release cortisol
What is cortisol vital for?
maintaining the health and wellbeing of the body when under stress, if activated over a long period of time it becomes depleted
What effect does very high arousal have on performance?
low performance
What sort of arousal leads to highest performance?
medium
Which hormone is first released in times of stress?
adrenalin
What is the name of the hormone released to maintain the functioning of the body in times of stress?
cortisol
What happens if cortisol is depleted?
decreased immunity
Causes of stress:
- life events
- acculturation
- daily pressures
- catastrophes
Life events: - marriage, divorce - death of a loved one - job lost Acculturation: - new values, laws and traditions - loss of status, financial strain - loss of social support, culture Daily pressures: - travel - traffic jam - new job Catastrophes: - flood, fire, earthquake, tsunami - war, industrial accident
What is the general adaptation syndrome (GAS) ?
explains the experience of stress from a physiological perspective, the model was the first to describe stress from a biological perspective
Three bodily stages of (GAS)
- alarm reaction
- stage of resistance
- stage of exhaustion
GAS - Alarm reaction (shock)
resistance to stress: below normal
symptoms: the body acts as though it is injured, blood pressure and body temp drop
GAS - Alarm reaction (countershock)
resistance to stress: above normal
symptoms: sympathetic nervous system is activated; flight- fight- freeze response activated, adrenalin released
GAS - Resistance
resistance to stress: above normal
symptoms: cortisol is released and all unnecessary functions are shut down, the individual appears as though all is normal
GAS - Exhaustion
resistance to stress: below normal
symptoms: resources are depleted, immune system is left weakened and prolonged release of adrenalin has negative effects on the body, the individual is susceptible to illness and disease
Strengths of GAS
- it measures a predictable pattern that can be measured in individuals
- if stress is not prolonged stages are still experienced, therefore tracks biological patterns in different types of stress
Limitations of GAS
- research was not conducted on humans
- does not account for individual differences and psychological factors
In which stage of GAS is cortisol most likely released?
resistance
Psychological factors of stress
- personality
- optimism vs pessimism
- risk taking and challenge
- lifestyle pace and demands
- past experiences with stress
- family and friends influence and support
- resources and support network
Lazarus and Folkman’s transactional model of stress and coping
- stress involves an encounter (transaction) between an individual and their external environment
- a stress response depends upon the individuals interpretation (appraisal) of the stressor and their ability to cope with it
- reappraisal is an important component of stress appraisal
Lazarus and Folkman’s transactional model of stress and coping (primary appraisal)
assesses the situation, is it positive, benign or stressful, if stressful what kind of stress?
Lazarus and Folkman’s transactional model of stress and coping (secondary appraisal)
assesses the available resource to deal with demands, internal resources, such as character and personality and external resources, such as support network and money
Lazarus and Folkman’s transactional model of stress and coping - coping mechanisms
involve problem- focused coping and emotional based coping
Lazarus and Folkman’s transactional model of stress and coping - Strengths
- accounts for individual differences in responses
- responds to changes in individuals response through reappraisal
Lazarus and Folkman’s transactional model of stress and coping - Limitations
- lack of empirical evidence
- an overlap between primary and secondary appraisal stages
Self efficacy (stress)
the beliefs we have about our abilities affect our actual outcomes
Resilience (stress)
one’s ability to adapt to stress and adversity
Coping flexibility
- the ability of an individual to replace an ineffective coping strategy with a different strategy one
- positive outcomes for the individuals with high coping flexibility
- high levels are linked to low incidence of mental illness, but measurement tools can be inconsistent
Approach strategies
- involve behaviours that attempt to decrease the stress by alleviating the problem i.e - applying for jobs, commence homework
- approach strategies are typically a healthy response to stress
Avoidance strategies
- involve avoiding dealing with the stress by protecting oneself from psychological distress i.e - denial, substance abuse, oversleeping, overeating, shifting blame
- avoidance strategies are typically maladaptive, unhealthy for the individual and unhelpful for relieving the source of stress
Coping strategies
can be adaptive, effective, maladaptive or ineffective
Problem- focused strategies
aim to reduce the stressor
Emotion- focused strategies
aim to change the unpleasant emotions associated with the stressor
Parasympathetic nervous system
- decreases activity (peace)
- calms the body after action
- dominates the SNS most of the time (during routine, everyday activities)
5 sources of stress
- daily pressures
- life events
- acculturative stress
- major stressor
- catastrophes
Context- specific effectiveness
refers to the coping strategy ‘matching’ the stressor, for example, if a student has a big test coming up, a coping strategy that incorporates positive action, such as study, would be effective
How can exercise reduce stress?
- using up stress hormones in the blood for energy (cortisol)
- increases cardiovascular fitness and stamina, increasing an individual’s ability to cope with future stressors
- beta-endorphins, which promote relaxation and wellbeing, are released during exercise
- providing a distraction from the stressor
