The imagination that is raised in man (or any other creature endued with the faculty of imagining) by words, or other voluntary signs, is that we generally call understanding, and is common to man and beast. For a dog by custom will understand the call or the rating of his master; and so will many other beasts.
The fight or flight response refers to the physiological response to stress. It is the body's automatic response that occurs when we perceive a situation as dangerous or stressful. This sets off a chain of chemical and hormonal reactions so your body can be ready to fight or flee to keep you from harm.
Physiologists define stress as how the body reacts to a stressor, real or imagined, a stimulus that causes stress. Acute stressors affect an organism in the short term; chronic stressors over the longer term. Alarm is the first stage, which is divided into two phases: the shock phase and the antishock phase. Shock phase: During this phase, the body can endure changes such as hypovolemia, hypoosmolarity, hyponatremia, hypochloremia, hypoglycemiaâthe stressor effect.