The Fight Or Flight Response

Question 1

Fight or flight

step 1)

Answer 1

Often the endocrine system and the ANS work in parallel with one another, for instance during a stressful event.
When a stressor is perceived by the hypothalamus the ANS changes from it’s normal resting state (parasympathetic state) to the physiologically aroused, sympathetic state.

Question 2

Step 2)

Answer 2

The hypothalamus recognises the threat and sends a message to the adrenal gland (specifically the adrenal medulla)

Question 3

Step 3)

Answer 3

This triggers the release of adrenaline into the bloodstream and noradrenaline into the brain. This triggers physiological changes in the body (e.g. Increased heart rate) which creates the changes associated with the sympathetic response. These changes explain why stress and panic is often experienced as a sick feeling.

Question 4

Step 4)

Answer 4

Once the threat has passed, the parasympathetic branch of the ANS works in opposition to the sympathetic nervous system.
It’s actions are antagonistic to the sympathetic system.
The parasympathetic system acts as a break and reduces the activities of the body that were increased by the actions of the sympathetic branch.

Question 5

Effects of sympathetic action

Answer 5

Heart rate increases 
Pupils dilate 
Intestine/gut action slows 
Salivation stops (mouth dries) 
Inhibits digestion increases breathing rate

Question 6

Effects of parasympathetic action

Answer 6

Heart rate decreases 
Breathing rate decreases 
Pupils constrict 
Intestine/gut action restored 
Stimulates digestion 
Salivation restored

Question 7

Fight or flight response

Answer 7

The way an animal responds when stressed.
The body becomes physiologically aroused in readiness to fight an aggressor or flee.
The action of the sympathetic section of the ANS prepares you for fight or flight.
When the danger has passed the action of the parasympathetic section restores your body functions back to their normal state or ‘rest or digest’.