Stress

Question 1

What is stress?

Answer 1

• Anything that throws your body out tof homeostasis balance
  (Sapolsky., 1994)

Question 2

What are three sources of stressors??

Answer 2

1. Environmental (temperature, noise)
2. Physiological (food, water)
3. Psychological (social, novel situations)

Question 3

What is considered stressful?

Answer 3

• An interpretation of the individual
• Something that is stressful to someone, might not be to another person
• Stress causes arousal that is considered adversive

Question 4

What is the HPA axis?

Answer 4

Adaptational responses that help our bodies come back to homeostatis

Question 5

What is the HPA axis split into?

Answer 5

1) Acute stress response
2) Long term stress responses

Question 6

What are the stages of the HPA axis?

Answer 6

Hypothalamus (CRH) -> Pituitary (ACTH) -> Adrenal gland (cortisol, adrenaline, noradrenaline)

Question 7

What type of loop is the HPA axis?

Answer 7

Negative feedback loop
- cortisol regulates a negative feedback loop
- high cortisol means less CRH and ACTH is released

Question 8

What is the acute stress response?

Answer 8

1. soemthing bad happens
2. hypothalamus sends a neuronal signal
3. activates teh adrenal medulle
4. secretes adrenaline and noradrenaline

Question 9

What is adrenaline?

Answer 9

Only released when you are stressed. Prepares body for an acute stress response
- Increases heart rate and blood pressure
- brings more blood flow to brain and muscles

Question 10

What is noradrenaline?

Answer 10

Always present in the body
- Continuously released into the blood stream
- Narrows blood vessels to increase blood pressure

Question 11

What do adrenaline and noradrenaline do?

Answer 11

Gets body ready for energetic release
- Raises blood glucose levels
- Stimulates respiratory and cardiovascular systems

Question 12

What is the energy used for in fight or flight?

Answer 12

1. contronting the stress
2. run away
3. stems from our evolutionary past

Question 13

Tell me about the parachute jump study **(Benschop et al., 1996) **- adrenaline and noradrenaline

Answer 13

1. Studied parachute jumpers
2. Measured both adrenaline and noradrenaline before jumping out the plane (baseline), the point they jumped and hours after (post-baseline)

**Results **
- Stress responses are adaptive
- The more teh system learns that it is not a survival sutuation, adrenaline levels do not increase as high as the first jump

Question 14

Describe the long term stress responses…

Answer 14

ONCE the stressor has occured - our body deals with long term stress responses
- Once the body has released adrenaline = CRH released which stimulates ACH from pituitary gland
- **ACTH **travels to **adrenal gland **and stimulates cortisol

Question 16

What type of loop is the long term stress responses?

Answer 16

NEGATIVE!!

Question 17

What is the role of cortisol?

Answer 17

Shuts down any function that may get in the way of fight or flight response
- Its a steriod

Question 18

What does high cortisol over a long period of time mean?

Answer 18

SLOWER recovery from stress

Question 19

Give me two acute stress response adaptations.

Answer 19

1. Increased oxygen intake
2. Decreased pain percpetion
3. Enhanced cognition

Question 20

Give me two pathologcial states associated with chronic stress

Answer 20

1. Fatigue; Steroid diabeties
2. Inhibited growth and reapir process of the body

Question 21

Does cortisol have activational or organisational effects?

Answer 21

BOTH!
- cortisol has both activational and organisational effcts on brain and behaviour

Question 22

What are organisational effects?

Answer 22

Long lasting, estbalished in the critical period
- These effects organize the brain’s structure and function in a way that influences behavior later in life

Question 23

What are actiavtional effects?

Answer 23

temporary - alter pre exisiting behaviour
- depend on current hormonal environment and are reversible

Question 24

What happens if there is a high level of cortisol in critical periods of developement?

Answer 24

During critical periods of development, if there is a high level of the steriod hormone…
- Can permenatly change a person’s ability to cope with stress (irreversible)

Question 25

Describe the two studies to display Pre-natal stress 1. in rats 2. in humans x2

Answer 25

**In rats ** 1. **Stress a pregant rat** = permenantly changes offspring **HPA axis** 2. a normal stress response should have a high peak then drop down Results 1. The response to a rat who experienced high levels of stress prenatally inside the womb were **blunted** In humans (1) **Van Os and Selten (1998)** 1. Invasion of Netherlands by Nazis 2. Time where women were highly stressed 3. Mothers in secind trimester = children grew up with **schizophrenia** In humans (2) Weinstock (1997) - Women who are stressed in pregancy were more likely to have **smaller babies** - Growth hormones were suppressed - bc of cortisol

Question 26

Describe the studies to display neonatal stress 1. In rats 2. Humans

Answer 26

**Rats** 2) Rats (Lui et al., 1997) - early stressful experience can positively influence rats - Presenting rats with mild stress after birth (separation from mother) - They were better able to deal with stressors - Dont know about this concept in humans (mild - harsh threshold) Humans Romanian orphan study - Experienced higher levels of stressors Gunnar et al., 2001 - Comparison of cortisol concentraions 6-12 years later after leaving orphanage CONTROLS CANADIAN BORN CHILDREN = Childrens adopted out at 8 months old mirror canadian chldrens cortisol concentartions = After - strong positive correlation with high cortisol levels Suggests that the window is 8 months

Question 27

What is the direction between stress and behaviour?

Answer 27

Bi-directional - Stress affects behaviour, but behaviour can also affect stress responses

Question 28

What are the 4 things stress response can be coped with?

Answer 28

1. Control 2. Predictability 3. Outlets for dealing with frustration 4. Habituation

Question 29

What does control involve to cope with stress? Weiss (1968)

Answer 29

1. Put rats into containers 2. Given mild electric shocks 3. Predicted that both rats should feel equally stressed 4. One rat had a lever in box which could turn shock off 5. Turn off = lower stress levels

Question 30

Predictability to cope with stress (Sapolsky., 1992)

Answer 30

- Same rat paradigm as control - When a light came on (signal) to instigate that a shock was coming - These rats did not have gastric ulceers compared to rats who did not get the warning signal

Question 31

Describe outlets for frustration to cope with stress

Answer 31

**Sapolsky., 1992** - Giving rats a piece of wood to chew on reduced stress levels **Soussignan & Koch., 1985** - Leg swinging in children has been shown to reduce stress levels

Question 32

Describe Habituation as a way to cope with stress

Answer 32

- Getting used to the stress - By doing the same thing which is causing the stress - body gets used to it

Question 33

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