a center in the brain, produces 6 hormones, of which 1 is ACTH (Adrenocorticotrophine Hormone). This is secreted into the blood at time of stress; the adrenal glands (above the kidneys) are activated.
the General Adaptation Syndrome consists of the Alarm Reaction, where the body first counters the stressful event; the Stage of Resistance, where the body is working to cope with stress. Either the stress goes away and the Stage of Resistance ends or the stress continues and the Stage of Exhaustion follows, including shock and death from the starvation of the brain.
Prolonged stress (stage of resistance
can be tolerated with proper nutrition and rest, but the effects of persistent cortisol in the system can become chronic. Depression, apathy and joylessness are symptoms.