Stress Flashcards
(138 cards)
What is Stress?
A state of physiological or psychological strain caused by an event that tends to disturb the functioning of the body
What is a stressor?
- A stimulus that causes the stress response
- e.g. an exam, a relationship breakdown or moving house.
What pathways deal with short term effects of stress?
The sympathomedullary (SAM) pathways
Describe how the SAM pathways deal with short term effects of stress
- The hypothalamus activates the sympathetic branch of the autonomic nervous system causing the adrenal medulla to release adrenaline
- This stress hormone gets the body ready to fight or flight by increasing the arousal of the sympathetic nervous system and so lead to increased heartbeat, blood pressure, breathing rate and inhibit digestion
What axis regulates and controls the body’s longer response to stress?
The hypothalamic-pituitary-adrenal axis (HPA)
What organs help regulate and control the body’s longer response to stress with the HPA?
- The hypothalamus
- The pituitary gland
- The adrenal gland
Describe how the HPA and other organs regulate and control the body’s longer response to stress
- In response to a stressful situation the hypothalamus activates the pituitary gland, which causes ACTH to be released, which stimulates the adrenal cortex to release corticosteroids, such as cortisol.
- These stress hormones have a number of functions, they cause the liver to increase the release of glucose and suppress the immune system and control swelling after injury
Which “organs” can sense if your blood contains the right level of cortisol?
- Hypothalamus
- Pituitary Gland
What happens if your cortisol levels are too low?
- Your brain adjusts the amount of hormone it makes
- Your adrenal gland picks up on these signals, then they fine tune the amount of cortisol they release
What happens to cortisol when your body is on high alert?
- Cortisol can alter or shutdown functions that get in the way
- This may include the digestive system. reproductive system, your immune system, or even your growth processes
Role of Cortisol
- Essential hormone that affects almost every organ and tissue in your body
- Plays an important role in regulating your body’s stress response
- Helps control your body’s use of fats. proteins and carbohydrates, or your metabolism
- Helps maintain blood pressure, immune function and the body’s anti-inflammatory processes
How does cortisol maintain blood pressure and why is this bad?
- Cortisol constricts blood vessels and increased blood pressure to enhance the delivery of oxygenated blood
- Advantageous for fight or flight situations but over time, arterial constriction and high blood pressure can lead to vessel damage and plaque build up, this can lead to cardiovascular disorders
What is Cushing’s syndrome?
A disorder where the body makes too much of the hormone cortisol over a long period of time
Whats Addison’s disease?
A disorder where the body makes too little of the hormone cortisol
Describe how Cortisol goes through the body?
- When the PAS system is activated the pituitary gland releases ACTH which travels via the bloodstream to the adrenal cortex and releases stress-related hormones, including cortisol.
- Cortisol permits a steady supply of blood sugar to give an individual energy to deal with the stressor, by tapping into protein stores via gluconeogenesis in the liver.
- This energy can help an individual fight or flee a stressor. However, elevated cortisol over the long term consistently produces glucose, leading to increased blood sugar levels.
- Over time this can lead to impaired cognitive ability and reduced immune functioning.
Cortisol AO3
Newcomer et al (1999)
- Found participants given levels of cortisol high enough to produce blood-sugar levels similar to those experiencing major stress events, were poorer at recalling prose passages
- compared to participants given cortisol only high enough to produce a stress response similar to minor surgery (e.g. stitches out)
- Suggesting high levels do impact on cognitive functions.
Cortisol AO3
Vgontzas et al (2013)
Found chronic insomniacs had increased PAS system leading to high levels of ACTH and cortisol.
Who came up with The General Adaptation Syndrome (GAS)?
Hans Selye
What did Selye argue?
Selye argued that stressors produce the same reaction in all animals (including humans).
What is GAS?
- A 3 stage set of physiological processes which prepare, or adapt, the body for danger so that we ready to stand a better chance of surviving it compared to if we remained passively relaxed when faced with a threat
What are the three main stages of GAS?
1) Alarm Reaction
2) Resistance
3) Exhaustion
Explain the “Alarm Reaction” stage in GAS
- The ANS responds to stress and the SAM and HPA are activated.
- Thus, the stress hormones, corticosteroids, cortosol, adrenaline, and noradrenaline are released and the body is ready for “fight or
flight”. - Heartbeat, blood pressure, and breathing rate increase and sugar is released into the blood to provide the body with energy.
Explain the “Resistance” stage in GAS
- The parasympathetic nervous system takes control as the body attempts to cope with the stress.
- The alarm symptoms disappear and the body appears to have returned too normal but stress hormones are still being released at an increased level.
- The body cannot continue to resist the stress indefinitely because it cannot generate new resources at the same speed as they are being used.
- If the stress ceases or is resolved then damage is unlikely, but if it persists the adrenal glands become enlarged and resistance declines further.
Explain the “Exhaustion” stage in GAS
- This is when the stressor persists until the body is no longer able to cope as its resources and defences are exhausted.
- The alarm symptoms reappear and the adrenal glands no longer function normally.
- If the stress does not cease, the
damaged adrenal glands can cause the parasympathetic nervous system to fail, and suppression of the immune system. - This leaves the body vulnerable to
stress-related illnesses, such as high blood pressure, heart disease, etc., and possibly death.