Outline the fight or flight response

The fight or flight response is the body and brains reaction to a situation, resulting in either to withstand the situation (fight) or flee the situation (flight). Firstly the hypothalamus,a region of the forebrain which coordinates both the autonomic nervous system and the activity of the pituitary, prepares the body for an action/emergency response. This results in the release of adrenaline which is from the adrenal gland/medulla. This then triggers and switches from parasympathetic to sympathetic activity and back again. Direct effects of adrenaline include constricted blood vessels, increasing rate of blood flow which raises blood pressure and an increased heart rate. Blood is also diverted away from the skin, kidneys and digestive system which thus increases blood to brain and skeletal muscle, enhancing respiration and sweating.