3B - Selye’s General Adaptation Syndrome - biological model of stress

Question 1

Stress as a biological process

Answer 1

• Stress is a psychobiological process, meaning the stress response involves both psychological and biological aspects.
• In order to develop an understanding of stress as a psychobiological process, it is important to understand how biological processes contribute to the stress response.
• Biological processes relate to physiological experiences that occur in the body, such as immune system functioning and the release of hormones.

Question 2

define Selye’s General Adaptation Syndrome

Answer 2

a biological model involving three stages of physiological reactions that a person experiences in response to a persistent stressor

Question 3

two elements when describing this syndrome

Answer 3

• It is non-specific, meaning it is the same irrespective of the type of stressor the organism is exposed to.
• It is identical within all members of a species, in this case rats

Question 4

The three stages of the GAS:

Answer 4

• Alarm reaction (shock and counter shock)
• Resistance
• Exhaustion

Question 5

define alarm reaction

Answer 5

the first stage of the General Adaptation Syndrome involving the initial decrease and subsequent increase in bodily arousal in response to an immediate stressor
- occurs when an individual first encounters and becomes aware of a stressor and the body responds to the immediate threat or challenge

Question 6

alarm reaction stage is divided into two substages:

Answer 6

• shock
• counter shock

Question 7

define shock

Answer 7

the first substage of the alarm reaction stage involving decreased bodily arousal for a brief period of time following the initial exposure to a stressor

Question 8

shock explanation

Answer 8

• This phase is also associated with a decrease in muscle tone, body temperature and blood sugar levels
• During this substage, the body experiences a temporary state of shock. It reacts as though it has been injured, as biological processes within the body fall below normal functioning.

Question 9

define counter shock

Answer 9

the second substage of the alarm reaction stage in which sympathetic nervous system responses occur that mobilise the body to respond to the stressor
- A rebound, increased ability to deal with stress

Question 10

counter shock explanation

Answer 10

• the body attempts to compensate for the acute stress response in the shock phase.
• Sympathetic NS is activated → FFF, increased heart rate
• Then cortisol is released → provides energy to confront stress
• Physiological changes associated with this phase include increases in muscle tension, heart rate, breathing rate, blood glucose and temperature.
• The alarm reaction stage does not usually last very long; sometimes just a few seconds, sometimes longer
• When a person enters counter shock, their levels of bodily arousal, and therefore their ability to deal with the stressor, increase to above normal.This marks the beginning of the increase in levels of resistance to stress that continues into the second stage of the GAS

Question 11

define resistance

Answer 11

the second stage of the General Adaptation Syndrome involving maintaining high levels of bodily arousal in response to a persistent stressor
- the body’s resources are maximised to cope and adapt over time

Question 12

resistance explanation

Answer 12

-Resistance is an adaptive stage because the body adjusts to the physiological changes that occurred during counter shock, including increased hormone levels and increased bodily arousal
- the parasympathetic NS will restore balance (e.g. reduce heart rate)
- adrenaline and cortisol continue to circulate, with cortisol persisting longer, providing energy to deal with stress
- but, cortisol will suppress the immune system, increasing susceptibility to illness (e.g. cold, minor infection or headache) as cortisol interferes with the body’s ability to fight disease leading to problems occuring and eventually the body begins to show physiological signs of wear and tear
- These sympathetic nervous system responses decrease in intensity as the body attempts to stabilise its internal environment.

Question 13

resistance stage and cortisol

Answer 13

• When the stressor persists over a prolonged period and the individual has to adapt to its ongoing presence in this stage, the body is actively dealing with the stressor.
• The body’s ability to deal with the stressor, and its level of resistance to it, continues to rise above normal.
• Cortisol levels are at their highest, which helps repair any damage to the body and maximises the body’s resources to cope and adapt to the stressor over time.

Question 14

define exhaustion

Answer 14

the third stage of the general adaptation syndrome, in which the continued depletion of energy stores and high levels of hormones such as cortisol decrease resistance to the stressor and impair the immune system
- resulting in an inability to cope with the stressor

Question 15

exhaustion explanation

Answer 15

• When a person enters exhaustion, cortisol and other stress hormones have been present in the bloodstream for a prolonged period of time, suppressing immune system functioning
• Energy stores become depleted and excess cortisol in the bloodstream over a long time impairs the immune system and gut function
• Ultimately becoming more susceptible to a variety of physical and psychological conditions such as infection, sickness, sleep disturbances, high blood pressure, fatigue, anxiety and depression.
• They are also more susceptible to serious chronic conditions, such as cardiovascular disease.

Question 16

exhaustion and the bodies biological function

Answer 16

• By the time a person has entered exhaustion, exposure to the stressor has been prolonged and persistent.
• During exhaustion, the body becomes unable to maintain these heightened levels of physiological arousal because bodily resources, such as energy and stress hormones, have been depleted.
• Therefore, levels of bodily arousal and the ability to deal with the stressor decrease to below normal.
• The person experiencing exhaustion can no longer cope with the demands of the stressor and is also unequipped to confront any other stressors that may arise.

Question 17

The explanatory power of Selye’s General Adaptation Syndrome

Answer 17

• it is a powerful model for explaining the stress response from a biological perspective.
• However, as with any scientific model, it does not always accurately reflect the full complexity of the experience of stress.
• successfully explains the stress response in terms of physiological reactions that occur in the presence of stressors.
• Therefore, it serves as a useful model for explaining the biological processes involved in the stress response.
• However, as with any scientific model, this model of stress is not a perfect explanation of the stress response.
• It has limitations in its ability to completely capture the complexity of the phenomenon it attempts to explain