Approaches: Flight or Fight?
The fight or flight response is the process of an animal or human responding to a physiologically arousing situation, Eg; something that gets you stressed (exams) or excited (rollercoasters, a crush). It involves both the autonomic nervous system and endocrine system, but the effects are mainly caused by the sympathetic nervous system and the parasympathetic nervous system, which reverses the effects afterwards.
When an “arousing” situation is detected by sensory systems, the hypothalamus (a part of the brain) is told. This then triggers the sympathetic nervous system, which releases hormones from the adrenal medulla into the bloodstream. This causes a number of changes in the body, and slows down the digestive and immune systems but also increases several systems. For example, your friend tries to scare you, your body would experience these changes:
Increased heart rate and blood pressure which give quick energy.
Dilated pupils (to take in as much light as possible) which temporarily improves our vision.
Tensed up muscles, as they have more energy from the glucose and adrenaline, which gives extra speed and strength.
Saliva production decreased, as blood flow to the digestive system is lower.
Increased breathing rate, so muscles can be re-oxygenated quicker, thus helping us react quicker.
The hypothalamus also activates the sympathetic nervous system. This system tells the adrenal medulla to release adrenaline and noradrenaline, which are key in the fight or flight response. These are the ‘stress’ hormones, and are best known for creating the shaky and heart-pounding felling in dangerous or exciting situations.
The parasympathetic nervous system then returns the body to its ‘normal’ state, once the situation is over. Sometimes known as the 'rest and digest' system, it reverses the activity of the sympathetic nervous system and restarts the immune and digestive systems.
