Psychology - Biopsych - Fight or Flight

Strengths of the pituitary-adrenal pathway

- biological explanation of stress allows accurate, objective measures to be made.

What is the role of the hypothalamus?

- cerebral cortex evaluates whether something is a stressor. - if it is, it sends signals to the hypothalamus. - this triggers one of two processes: sympathomedullary pathway (fight or flight) pituitary-adrenal pathway (chronic stress)

Weaknesses of the fight or flight response

- gender differences - Taylor et al (2000) said that acute stress causes the fight or flight response in men but the tend and befriend response in women. - many studies focus on men. - most research is carried out on animals. - it may be hard to establish a cause and effect relationship. - there is considerable variation in level and type of hormones released by different people and in response to different stressors- not a simple physiological process.

Strengths of the fight or flight response

- gender differences make evolutionary sense as if the women fought or fled they would put the offspring in danger. - many studies use objective measurements. - fight/flight response can be seen in all mammals in response to threats.

What is the pituitary adrenal pathway?

- hypothalamus triggers release of CRH. - CRH stimulates anterior pituitary. - this releases ACTH that stimulates the adrenal cortex. - this then releases corticosteroids which give us energy by encouraging glucose synthesis from non-carb sources ( fats and proteins. - this energy is needed to replace that used by the initial reaction to stress.

What is the sympathomedullary pathway?

- hypothalamus triggers the sympathetic branch, that becomes more active when the body is stressed. - this stimulates the adrenal medulla within the adrenal glands. - adrenal medulla releases adrenaline (hormone) and noradrenaline (neurotransmitter). - these things make the blood pressure and heart rate increase to move blood quickly around the body. - they cause digestion to decrease so more blood is directed to the brain and muscles. - they cause muscles to tense so the body is physically responsive. - they increase perspiration to cool down the body. - they increase breathing rate so more oxygen is sent to the muscles.

What is feedback?

- the hypothalamus and pituitary have receptors that monitor cortisol levels. - if they rise they initiate a reduction in CRH and ACTH to bring cortisol levels back down.

What happens when the threat has passed?

- the parasympathetic nervous system kicks in. - this is a slower acting system and it may take several minutes to get the body back to normal.

What is the fight or flight response?

a sequence of activity within the body that is triggered when the body prepares itself to attack or run to safety - involves changes in the NS and secretion of hormones.