The SAM system- Sympathomedullary Pathway
- Fight or flight response- an immediate stressor that is not long lasting e.g. a shock or a deadline. Cannon 1914- Dates back to prehistoric times
HYPOTHALAMUS: Releases CRF to the SNS
SYMPATHETIC NERVOUS SYSTEM: Sends noradrenaline to the adrenal medulla
ADRENAL MEDULLA: Converts noradrenaline into adrenaline ready for fight or flight
- The fight or flight response increases heart rate, inhibits saliva production
- The parasympathetic nervous system kicks in when the stressor is no longer there- this inhibits the fight or flight response
- The problem with the SAM system is that if the stress does not go away, we get exhausted and this can lead to health problems.
The HPA system- The Pituitary- adrenal system
- When the SAM system cannot cope and the stressor becomes chronic, the HPA system kicks in.
HYPOTHALAMUS: Releases CRF to the pituitary gland
PITUITARY GLAND: Sends ACTH through the blood to the adrenal cortex
ADRENAL CORTEX: Sends cortisol around the body
The hypothalamus checks if the stressor is still present and if it is the cycle continues
- Cortisol enables the breakdown of glucose to provide energy so the person can keep fighting the stressor.
- Can cause problems with thinking, high blood pressure and lowered immune functioning. Can lower serotonin.
GAS- General Adaptation Syndrome Seyle (1956)
Three stages of the General Adaptation Syndrome:
- Alarm stage- the presence of a stressful event is registered. The body is prepared for energy expenditure and thus poised for the fight or flight response.
- Resistance stage- The stress response is activated and so the body is seemingly coping with the stressor and so from the outside things appear to be under control.
- Exhaustion stage- If the stressor is chronic the body becomes exhausted. Hormone reserves become depleted and the body experiences raised blood pressure, ulcers, depression and anxiety, may develop.
- Many psychologists believe that the way our ancestors dealt with stress has led to different stress responses in men and women.
- In 2005, 70% of under 75's who died of CHD were men and 30% were women
- They argue that females have a greater investment in their offspring and therefore evolution has lead females stress response to no jeopardize the safety of offspring.
- Shelley Taylor et al (2000) believe that this should favour the development of biological mechanisms which inhibit the fight or flight response in females when they are faced with a threat. Females would attend to their young and befriend other females as a defense mechanism.