Fight-or-flight response
The fight-or-flight response (also known as the acute stress response) is a physiological reaction that occurs in response to a perceived harmful event, attack, or threat to survival. It was first described by Walter Bradford Cannon in the early 20th century. This response is a part of the autonomic nervous system and involves the activation of the sympathetic nervous system, resulting in the release of hormones such as adrenaline and noradrenaline.
Physiological Mechanism[edit]
When an individual perceives a threat, the hypothalamus activates the sympathetic nervous system. This leads to the release of adrenaline from the adrenal medulla. The release of these hormones results in several physiological changes, including:
- Increased heart rate (tachycardia)
- Increased blood pressure
- Dilation of the bronchioles in the lungs
- Redistribution of blood flow to the muscles
- Dilation of the pupils
- Inhibition of non-essential systems such as digestion
These changes prepare the body to either fight the threat or flee from it, hence the term "fight-or-flight."
Historical Background[edit]
The concept of the fight-or-flight response was first introduced by Walter Bradford Cannon in his work on the homeostasis of the body. Cannon's research demonstrated that the body's response to stress is a complex, coordinated effort involving multiple systems.
Role in Modern Medicine[edit]
Understanding the fight-or-flight response is crucial in the field of psychology and medicine. It is a fundamental concept in the study of stress and anxiety disorders. Conditions such as post-traumatic stress disorder (PTSD) and panic disorder are closely related to the dysregulation of this response.
Related Concepts[edit]
- General adaptation syndrome
- Homeostasis
- Sympathetic nervous system
- Parasympathetic nervous system
- Stress (biology)
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