Lecture 7: The Psychobiology of Stress

Question 1

Why do we study stress?

Answer 1

Stress can effect psychological morbidity, physical disease, disease progression and performance.

Question 2

How does stress get inside the body?

Answer 2

Something in the environment has changed and we need to respond to it. We see it as being stressful. Then activates 2 systems (Nervous and Endocrine) which interact with other systems (cardiovascular, digestive, immune and reproductive)

Question 3

How many pathways are there?

Answer 3

Two

Question 4

Where do the pathways originate and terminates?

Answer 4

Originate in Hypothalamus and terminate at the Adrenal Gland.

Question 5

How do we activate the pathways?

Answer 5

When we interpret a stressor, we activate the hypothalamus which activates the 2 pathways

Question 6

What is the Sympathetic Adrenal Medullary Axis?

Answer 6

The Hypothalamus sends a signal through the Nervous System to the inside of the Adrenal Medulla

Question 7

What is the second process?

Answer 7

The Hypothalamus stimulates the Pituitary Gland which stimulates the Adrenal Cortex. This process is slower as involves the secretion of hormones.

Question 8

What hormone is secreted by the Hypothalamus in the 2nd process?

Answer 8

Corticotropin releasing hormone and this stimulates the Pituitary Gland

Question 9

What hormone is released by the Pituitary Gland?

Answer 9

Adrenocorticotropic hormone and this stimulates the Adrenal Cortex

Question 10

(SAMA) What hormone is released from the Adrenal Medulla?

Answer 10

Adrenaline and Noradrenaline

Question 11

What are the roles of Noradrenaline and Adrenaline?

Answer 11

Increased HR and BP, redirection of blood muscles/organs

Initiates the Fight or Flight response

Question 12

What happens when you get a fright?

Answer 12

You release adrenaline and noradrenaline and start to initiate the pathways including the Pituitary Gland. Involves the secretion of hormones

Question 13

What are the roles of Cortisol?

Answer 13

Maintenance of Fight or Flight response. Increased:

• Sensitivity if cells to adrenaline and noradrenaline
• Blood sugar levels
• Mental Alertness

Question 14

What else does Cortisol do?

Answer 14

Switches off long term processes so resources can be directed to immediate threat

Question 15

What are the long term processes?

Answer 15

Immune system
Growth and Repair
Digestion
Reproduction
Regulation of Sleep patterns

Question 16

Why are stress responses essential in short term?

Answer 16

Mobilisation of resources to deal with immediate threat. Temporary increases on mental and physical abilities. Redirection of resources from long term processes to threat

Question 17

Why are stress responses harmful in the long term?

Answer 17

If the stress doesn’t go away then long term processes are switched off

Question 18

What can chronic stress lead to?

Answer 18

• Increased risk of ill health (immune)
• Inability to heal wounds (G+R)
• Increased risk of peptic ulcers (Digestion)
• Fertility problems (Reproduction)
• Development of insomnia (Sleep)

Question 19

How to measure stress hormones?

Answer 19

Adrenaline and Noradrenaline - draw blood
Can measure hr, bp and skin (sweat)
Cortisol can be measured by a salivary swab

Question 20

What is the Circadian (24hr) Cortisol Profile?

Answer 20

In first half of sleep cortisol is quite low
2nd half it begins to increase
When you wake in morning cortisol is high and begins to decrease during day
Reaches lowest when go to bed

Question 21

What is the Diurnal (daytime) Cortisol Profile?

Answer 21

Usually measure cortisol in daytime - awake so can do swab
30-45 mins after you wake get a serge in cortisol - called the Cortisol Awakening Response (CAR)
Diurnal decline
Lowest levels at night time called ‘Evening Nadir’

Question 22

How do you observe and activate the pathways in lab?

Answer 22

Controlled/lab stressors (usually acute stress). We know that individuals respond to acutely stressful stimuli. We can attempt to mimic these situations in the lab

Question 23

How do you observe and activate the pathways outside the lab?

Answer 23

Real world stress (usually chronic/enduring). Can observe and measure outside lab and compare higher and lower stress groups of individuals as they experience higher or lower stress periods

Question 24

What are some examples of controlled/lab stressors?

Answer 24

Public speaking, mental arithmetic, mirror tracing, stroop task, multitasking, noise/white noise, injections, watching gore, cold pressor, dental treatment

Question 25

What are some examples of real world stressors?

Answer 25

High stress jobs, excessive lifestyle, major life events, stressful living conditions, exam periods, caregiving

Question 26

Do students have elevated cortisol?

Answer 26

People who reported higher perceived stress wake up with higher cortisol levels. When they go to bed they have higher levels of cortisol than those with low stress

Question 27

Why do students have more health complaints?

Answer 27

People who are more stressed are showing extra activation of the hypothalamic Pituitary Adrena. Evidence by higher secretion of cortisol in morning and night. Makes people more vulnerable to illnesses

Question 28

Why look at ecstasy use and cortisol?

Answer 28

Problems reported by ecstasy users are also related to elevated levels of cortisol - impaired memory, sleep problems, depression and anxiety, ill health.
Many ecstasy users have high elevated cortisol, more stressed by multitasking

Question 29

What are some advantages of combining methods?

Answer 29

Able to assess effects of a life stressor on daily cortisol section and in response to acute stress. Heavy ecstasy users have elevated cortisol and greater response to acute stress. Maybe elevated cortisol levels are responsible for problems experienced by ecstasy users.