How does the body react during a fight-or-flight response?

The fight-or-flight response is a physiological reaction that occurs in response to a perceived threat or danger. During this response, the body prepares to either confront the threat or flee from it.

When the body experiences stress or fear, the adrenal glands release adrenaline (also known as epinephrine) and other stress hormones into the bloodstream. Adrenaline plays a critical role in the fight-or-flight response by enhancing the heart rate and increasing blood flow to muscles, which prepares the body for rapid physical activity. This response leads to an increased supply of oxygen and energy substrates, enabling a person to respond quickly in a dangerous situation.

Other physiological changes that occur during this response include a widening of the airways in the lungs to improve oxygen intake and a diversion of blood flow away from non-essential functions, such as digestion, to essential functions like muscle movement. This helps to ensure that the body has the maximum readiness to deal with the immediate threat.

In summary, during a fight-or-flight response, the release of adrenaline is key to accelerating heart rate and increasing blood flow, enabling quick action in response to stressors.