A2 Mock - Biological Explanations ( ACUTE STRESS)

Question 1

Explain the fight and flight response

Answer 1

One response to stress is the acute response also called the sympathomedullary pathway or fight and flight response. It is for sudden stressors such as dropping a mug of tea and controlled by the sympathetic pathway of the autonomic nervous system - the sympathetic nervous system.

Question 2

Explain Adrenaline and Noradrenaline

Answer 2

The autonomic nervous system is controlled by the hypothalamus (a structure in your brain). When confronted with a stressor the hypothalamus triggers the sympathetic nervous system which in turn causes the adrenal medulla (the middle part of the adrenal glands) to release the hormone adrenaline and the neurotransmitter noradrenaline into the bloodstream.

Question 3

Explain the physical changes

Answer 3

Adrenaline and noradrenaline cause your breathing and pulse rate to increase, raises blood pressure and makes pupils wider. They also shut down the systems in your body that you do not need to respond physically such as the digestive system.

Question 4

Explain the parasympathetic response

Answer 4

These changes in your body help you to defend yourself or run away. When the stressor goes away (you haven’t smashed the mug and have cleared up the mess) then the parasympathetic pathway decreases your arousal and promotes your digestive system again. This part of the autonomic nervous system is roughly opposite to the sympathetic.

Question 5

Explain the evolutionary response

Answer 5

This fight and flight response is an evolved response that helped our ancestors in the EEA to deal with their stressors that would have required a physical response. Unfortunately in the modern world the stress response can be triggered often by stressors that do not require a physical response. If under regular stress, the raising of blood pressure etc can lead to wear and tear on the heart and circulatory system leading to cardiovascular disorders.