Understanding the stress response - Harvard Health
Lissa shares 10 surprising "fight-or-fight" triggers to avoid. system is in “fight-or- flight,” the body's natural self-repair mechanisms are disabled!. The fight or flight response - what is it, really, and why should you care? like demanding bosses, money troubles, and the world of dating. Almost everyone is familiar with the fight-flight response—your reaction to a stimulus perceived as an imminent threat to your survival. However, less well- known.
When it perceives danger, it instantly sends a distress signal to the hypothalamus. Command center When someone experiences a stressful event, the amygdala, an area of the brain that contributes to emotional processing, sends a distress signal to the hypothalamus. This area of the brain functions like a command center, communicating with the rest of the body through the nervous system so that the person has the energy to fight or flee.
The hypothalamus is a bit like a command center. This area of the brain communicates with the rest of the body through the autonomic nervous system, which controls such involuntary body functions as breathing, blood pressure, heartbeat, and the dilation or constriction of key blood vessels and small airways in the lungs called bronchioles.
The autonomic nervous system has two components, the sympathetic nervous system and the parasympathetic nervous system. The sympathetic nervous system functions like a gas pedal in a car. It triggers the fight-or-flight response, providing the body with a burst of energy so that it can respond to perceived dangers. The parasympathetic nervous system acts like a brake. It promotes the "rest and digest" response that calms the body down after the danger has passed.
After the amygdala sends a distress signal, the hypothalamus activates the sympathetic nervous system by sending signals through the autonomic nerves to the adrenal glands. These glands respond by pumping the hormone epinephrine also known as adrenaline into the bloodstream. As epinephrine circulates through the body, it brings on a number of physiological changes. The heart beats faster than normal, pushing blood to the muscles, heart, and other vital organs.
Pulse rate and blood pressure go up. The person undergoing these changes also starts to breathe more rapidly. Small airways in the lungs open wide. This way, the lungs can take in as much oxygen as possible with each breath. Extra oxygen is sent to the brain, increasing alertness. Sight, hearing, and other senses become sharper. Meanwhile, epinephrine triggers the release of blood sugar glucose and fats from temporary storage sites in the body. These nutrients flood into the bloodstream, supplying energy to all parts of the body.
All of these changes happen so quickly that people aren't aware of them.
In fact, the wiring is so efficient that the amygdala and hypothalamus start this cascade even before the brain's visual centers have had a chance to fully process what is happening. That's why people are able to jump out of the path of an oncoming car even before they think about what they are doing.
As the initial surge of epinephrine subsides, the hypothalamus activates the second component of the stress response system — known as the HPA axis.
Fight-or-flight response - Wikipedia
This network consists of the hypothalamus, the pituitary gland, and the adrenal glands. The HPA axis relies on a series of hormonal signals to keep the sympathetic nervous system — the "gas pedal" — pressed down.
If the brain continues to perceive something as dangerous, the hypothalamus releases corticotropin-releasing hormone CRHwhich travels to the pituitary gland, triggering the release of adrenocorticotropic hormone ACTH.
This hormone travels to the adrenal glands, prompting them to release cortisol. The body thus stays revved up and on high alert.
10 Surprising Things That Trigger “Fight-Or-Flight”
When the threat passes, cortisol levels fall. The parasympathetic nervous system — the "brake" — then dampens the stress response. Techniques to counter chronic stress Many people are unable to find a way to put the brakes on stress. Rats, for instance, try to escape when threatened, but will fight when cornered. Some animals stand perfectly still so that predators will not see them.
Many animals freeze or play dead when touched in the hope that the predator will lose interest.
- Understanding the stress response
- What is the fight-or-flight response?
Other animals have alternative self-protection methods. Some species of cold-blooded animals change color swiftly, to camouflage themselves.
Thus, flight can be disappearing to another location or just disappearing in place. And often both fight and flight are combined in a given situation. The fight or flight actions also have polarity — the individual can either fight or flee against something that is threatening, such as a hungry lion, or fight for or fly towards something that is needed, such as the safety of the shore from a raging river.
A threat from another animal does not always result in immediate fight or flight. There may be a period of heightened awareness, during which each animal interprets behavioral signals from the other.The Fight Flight Freeze Response
Signs such as paling, piloerection, immobility, sounds, and body language communicate the status and intentions of each animal. There may be a sort of negotiation, after which fight or flight may ensue, but which might also result in playing, mating, or nothing at all.
An example of this is kittens playing: