Unit 2 PSYA2 (May exam)
Biological Psychology – Stress
Unit 2 Booklet 1 (of 2): Stress as a Bodily Response
Stress
First of all we need to answer the question- ‘What is stress?
There is no single definition of stress. Any definition of stress must take into account the internal factors (physiological changes), external factors (the situation itself) and cognitive factors (the person’s perception of the situation and their ability to cope with the demands of the situation).
How does the body respond to stress?
The stress response is important for survival in animals because the physiological changes associated with stress are essential in conditions of fight or flight (i.e. attacking or running away).
The stress response is therefore thought to be:
An innate, defensive and adaptive response that should promote survival.
A bodily response which enables an animal to react quickly to potentially dangerous stimuli (e.g. when an animal sees a predator, it feels “stressed” and becomes biologically aroused and ready to respond (fight or flight) more quickly to the situation).
Important because it increases physiological arousal as well as increasing motivation and concentration.
However……
Continual exposure to stressful stimuli, causing prolonged or repeated stress responses may affect health by causing stress-related illness (this will be dealt with later in the booklet…).
The Body’s Response to Stressors
There are two parts to the physical (or psychological) stress response system:
1. The Hypothalamic-Pituitary-Adrenal System (HPA)
2. The Sympathetic-Adrenal-Medullary Pathway (SAM)
AO1: The Hypothalamic-Pituitary-Adrenal System (HPA)
Some stressful experiences last for a long time, such as worrying about exams for months