If the threat, or perceived threat, persists, then the body also begins to release cortisol. Again, this is a critical function, cortisol being responsible for helping to regulate blood pressure and the immune system, and assisting balancing insulin to keep the blood sugar level normal, and generally helping the body to respond to stress. However, cortisol can also interfere with the function of neurotransmitters, the chemicals used by brain cells to communicate with each other. Too much cortisol can impair long-term memory, and people who have been in very stressful situations may have “gaps” in what happened, as the brain has been overwhelmed and has not been able to fully lay down the long-term memories. Our bodies are equipped to deal with all of this in short bursts: as the sympathetic nervous system releases the fight or flight response, so the parasympathetic nervous system will calm it down. However, the release of adrenalin is a much more effective and faster response ...