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The physiological basis of stress

What goes on inside our bodies when we experience stress? The physiological mechanisms of stress are extremely complex, but they generally involve the work of two systems—the sympathetic nervous system    and the hypothalamic-pituitary-adrenal (HPA) axis    . When a person first perceives something as stressful (Selye’s alarm reaction), the sympathetic nervous system triggers arousal via the release of adrenaline from the adrenal glands. Release of these hormones activates the fight-or-flight responses to stress, such as accelerated heart rate and respiration. At the same time, the HPA axis, which is primarily endocrine in nature, becomes especially active, although it works much more slowly than the sympathetic nervous system. In response to stress, the hypothalamus (one of the limbic structures in the brain) releases corticotrophin-releasing factor, a hormone that causes the pituitary gland to release adrenocorticotropic hormone (ACTH) ( [link] ). The ACTH then activates the adrenal glands to secrete a number of hormones into the bloodstream; an important one is cortisol, which can affect virtually every organ within the body. Cortisol is commonly known as a stress hormone and helps provide that boost of energy when we first encounter a stressor, preparing us to run away or fight. However, sustained elevated levels of cortisol weaken the immune system.

A figure shows an outline of the human body that indicates various parties of the body related to the hypothalamic-pituitary-adrenal axis. The hypothalamus, pituitary gland, and adrenal glands are labeled. There is an arrow from hypothalamus to pituitary gland and another arrow from pituitary gland to adrenal glands. These arrows represent the flow between these organs.
This diagram shows the functioning of the hypothalamic-pituitary-adrenal (HPA) axis. The hypothalamus activates the pituitary gland, which in turn activates the adrenal glands, increasing their secretion of cortisol.

In short bursts, this process can have some favorable effects, such as providing extra energy, improving immune system functioning temporarily, and decreasing pain sensitivity. However, extended release of cortisol—as would happen with prolonged or chronic stress—often comes at a high price. High levels of cortisol have been shown to produce a number of harmful effects. For example, increases in cortisol can significantly weaken our immune system (Glaser&Kiecolt-Glaser, 2005), and high levels are frequently observed among depressed individuals (Geoffroy, Hertzman, Li,&Power, 2013). In summary, a stressful event causes a variety of physiological reactions that activate the adrenal glands, which in turn release epinephrine, norepinephrine, and cortisol. These hormones affect a number of bodily processes in ways that prepare the stressed person to take direct action, but also in ways that may heighten the potential for illness.

When stress is extreme or chronic, it can have profoundly negative consequences. For example, stress often contributes to the development of certain psychological disorders, including post-traumatic stress disorder, major depressive disorder, and other serious psychiatric conditions. Additionally, we noted earlier that stress is linked to the development and progression of a variety of physical illnesses and diseases. For example, researchers in one study found that people injured during the September 11, 2001, World Trade Center disaster or who developed post-traumatic stress symptoms afterward later suffered significantly elevated rates of heart disease (Jordan, Miller-Archie, Cone, Morabia,&Stellman, 2011). Another investigation yielded that self-reported stress symptoms among aging and retired Finnish food industry workers were associated with morbidity 11 years later. This study also predicted the onset of musculoskeletal, nervous system, and endocrine and metabolic disorders (Salonen, Arola, Nygård,&Huhtala, 2008). Another study reported that male South Korean manufacturing employees who reported high levels of work-related stress were more likely to catch the common cold over the next several months than were those employees who reported lower work-related stress levels (Park et al., 2011). Later, you will explore the mechanisms through which stress can produce physical illness and disease.

Summary

Stress is a process whereby an individual perceives and responds to events appraised as overwhelming or threatening to one’s well-being. The scientific study of how stress and emotional factors impact health and well-being is called health psychology, a field devoted to studying the general impact of psychological factors on health. The body’s primary physiological response during stress, the fight-or-flight response, was first identified in the early 20th century by Walter Cannon. The fight-or-flight response involves the coordinated activity of both the sympathetic nervous system and the hypothalamic-pituitary-adrenal (HPA) axis. Hans Selye, a noted endocrinologist, referred to these physiological reactions to stress as part of general adaptation syndrome, which occurs in three stages: alarm reaction (fight-or-flight reactions begin), resistance (the body begins to adapt to continuing stress), and exhaustion (adaptive energy is depleted, and stress begins to take a physical toll).

Personal application question

Think of a time in which you and others you know (family members, friends, and classmates) experienced an event that some viewed as threatening and others viewed as challenging. What were some of the differences in the reactions of those who experienced the event as threatening compared to those who viewed the event as challenging? Why do you think there were differences in how these individuals judged the same event?

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Questions & Answers

What explanatory value do you think behavioral learning theory has for human behavior?
Kuurshejr Reply
what are the contributions of Darwin's evolutionary theory to psychology
Merit Reply
In thinking about the case of Candace described earlier, do you think that Candace benefitted or suffered as a result of consistently being passed on to the next grade?
Haley Reply
what is post traumatic stress disorder?
Nafisa Reply
can we ever think beyond books?
Chandrakant
what is schizophrenia?
Nafisa
Nafisa Sultana# Schizophrenia is characterised by thoughts or experiences that seem out of touch with reality, disorganised speech or behaviour and decreased participation in daily activities. Difficulty with concentration and memory may also be present.
Mohammad
ok..thanks a lot
Nafisa
and what about post traumatic stress disorder?
Nafisa
Nafisa Sultana# Post-traumatic stress disorder (PTSD) is a disorder that develops in some people who have experienced a shocking, scary, or dangerous event.
Mohammad
Posttraumatic stress disorder (PTSD) is a psychiatric disorder that may occur in people who have experienced or witnessed a traumatic event such as a natural disaster, a serious accident, a terrorist act, war/combat, or rape or who have been threatened with death, sexual violence or serious injury.
Mudit
okk
Nafisa
thanks
Nafisa
PAM🥂
Mudit
Hello! how we can apply CBT therapy? any source to learn practice it?
Isra
what are the four basic style of life? explain
Alysha Reply
Describe the characteristics proposed by Alfred Adler that kay develop on first born, second born, and youngest children as a result of their order of birth within the familys
Alysha
answer pl
Nss
it's complicated
Chandrakant
like how you count all these things and put them into a category?
Chandrakant
4 styles of life Authoritarian Authoritative Permissive Neglectful
Wajid
what does alfred adler differ from sigmund freud
Alysha Reply
One of the differences is that Adler had an holistic view of individuals when studying them whereas Freud worked on separate personality components
Syed
what are the differences between their theories
Alysha
heyyy
Crazy
Freudian theory of personality have basic components as ID,Ego,Superego. Freud have psychosexual developmental model of personality. Whearas Adler given Birth order in personality development also focused on Inferiority complex and superiority complex.
Wajid
thank you
Alysha
thanks guys for your information 👍
Sonu
my pleasure..
Wajid
Was Psyche rlly a Mortal woman
Elijah Reply
yes name psyche derived from anicient mortal women
Wajid
how much for book
Ashley Reply
Whose book?
Natalie
if it is for this book, psychological trauma and illuminations are each taxed differently depending on your mental preparedness to engage in the subject.
Nathaniel
tell me 5 best things that a woman can do better than a guy and a guy can do better than a woman?
Chandrakant
I just know this that women have more emotional intelligence than men and men are more practical than women
Samiha
Yes womens emotional intelligence as mother is more than father and father is more practical than a mother
Wajid
does this apply to the career in applied behavior analysis?
Nicole Reply
Actually I really don't know much about psychology because my age is just 13 ..but I am interested in this subject.I feel it important..to know human behavior and about the world not materially but emotionally.. Can you help me from now to take the courses of psychology from now?
Nafisa
I can try. im only in my 2nd year
Nicole
read, take notes, study ask questions, study some more. you"ll do just fine. u made it this far.
jeddy
yes it does.
jeddy
age isn't a barrier.
jeddy
same here I am even 12 And I am interested in psychology reading and knowing is ok but what about exams
Vaishali
I have downloaded an app where I used to give exam per day
Nafisa
heyy.. I'm new here..can I know what is this chat box used for?
pakki
would you please recommend the app
Vaishali
here u can clear u doubts ..if u r having any problems
Nafisa
Hi can you help me? I need ideas for my thesis title related to psychology
Mercelyn
what's the subject?
Nicole
@nafisa name that app....
Ishan
psychology quiz
Nafisa
Don't learn psychology, learn what is the possibilities of mind then you will get know what is the psychology in real sens.
Mohammad
that's very truee
Nafisa
hii everyone I m new here
ROFIKUL
hmm
Nafisa
hello guys..go through q youtube and watch some psychological facts about human ....it is really very interesting....
Nafisa
Watch the illusions and be aware about it🤗
Nafisa
all information teaches something, its just not always truth.
Nathaniel
agreed
Teena
yes nafis what kind of help do you need
Wajid
no sir..
Nafisa
I was recently diagnosed schizophrenic. after a lifetime of major depression. time I did hear voices not for long. how does one know if they really schizophrenic?
Cathy Reply
because psychology is the dissection and study of the mind, some find it hard to believe a diagnosis under mental health concerns. if you feel you have been misdiagnosed, go to another doctor. be 100% honest in all questions asked. to lie to your doctor is much like lying to yourself/hurting self
on the contrary, a diagnosed schizophrenic doesn't always have episodes. it may start off very mild and progress over time. it may also be triggered by events/situations/certain states of mind the patient may experience
diagnosed schizophrenics are normally prescribed a medication that can help. if you feel your medication is not working, or that it may make matters worse, discuss this with your doctor so he/she can make adjustments. what works for one person may not work for them all, and so doctors need to know
i want to study about psychology b'coz my father has a mental illness. iwant to help my father to healed from her sicknessed.
Layca
please whats the answer
Fortune Reply
answer to what?
Gaunt
what is mean by what?
Mohammad
to the questions ooo i can't find the answers
Fortune
Can you repeat the question or comment the page you saw it?
Haim
why they named it psychology
zayn Reply
telll me
ABDUL
the word "psychology" comes from the Greek words "psyche" meaning life and "logos" meaning "explanation".
Soma
Psyche, in Greek mythology was a goddess who comes to represent the human soul's triumph over the misfortunes of life. The term psychology was coined. Psyche, meaning soul or mind and the root "ology" meaning the study of. I hope this helped.
JC
well done
ABDUL
how you convince a drug addict not to consume drugs?
Chandrakant
advise them to do exercises and keep themselves energetic, and tell them to control their urge and whenever they get an urge just go for a jogging or something (I'm not a professional, I'm only telling my point of view so please do ask someone else too)
Samiha
ya I appreciate wat you said
Chandrakant
you r sweet tho samiha 😊😊
Chandrakant
what is chunking
Ritika Reply
Chunking is a process by which individual pieces of an information set are broken down and then grouped together in a meaningful whole.
Azquan
chunking is to information as syllabus is to word
ABDUL
what dose it means, operant and classic conditioning in short words?
Mikiyas Reply
classical conditioning is based on association between unnatural stimulus to natural response whether the conditioning on the basis of consequences is known as operant conditioning.
Wajid
okk
Nafisa
well said Mr.Wajid
Maryam
well..
Nafisa
example in humans lacking education
Olivia
scientific method, critical thinking.
jeddy Reply
the dealings with the thought process and human behavior.
jeddy
for acquiring knowledge by experimentation.
jeddy
study scientific study of mind and behavior.
jeddy
scientific study of the human mind and behavior.
jeddy
hey jeddy I have question s for you
Yussuf
hi what is behavioralism ?
jusem
what is psychology..?
Ania
the science of mental life.
Mikiyas
it focuses on understanding and modifying human behaviour
ABDUL

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Source:  OpenStax, Psychology. OpenStax CNX. Feb 03, 2015 Download for free at https://legacy.cnx.org/content/col11629/1.5
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