Stress And Behaviour 10

Question 1

What are some examples of stress and unpredictability in the environment?

Answer 1

Drought and extreme weather events

Question 2

What are some predictable factors that animals can prepare for to prevent stress?

Answer 2

Seasonality

Question 3

What is the emergency life history stage?

Answer 3

If an animal experiences a severe perturbation it can abandon its normal activities and enter a coping state until the perturbation ends

Question 4

What is allostasis?

Answer 4

The process of maintaining stability- refers to mechanisms maintaining homeostasis

Question 5

What does allostatic load refer to?

Answer 5

The increased workload needed to maintain stability in response to perturbation

Measured by overall energy expenditure

Question 6

What happens if allostatic overload is reached?

Answer 6

The emergency life history stage is triggered

Question 7

What is predictive homeostasis?

Answer 7

Values associated with predictable day to day and seasonal activities- the normal range when there is no particular threat

Question 8

What is reactive homeostasis?

Answer 8

The values encountered in response to unpredictable changes in the environment- when the animal reacts to a threat

Question 9

What is homeostatic failure/homeostatic overload?

Answer 9

When the animal fails to react to the threat or can’t deal with the stress

Question 10

What are the two main hormones secreted by the adrenal gland during a stress response?

Answer 10

Adrenaline and glucocorticoid steroids

Question 11

What does the activation of the HPA axis do?

Answer 11

Causes the release of glucocorticoid steroids from the adrenal cortex

Question 12

What is the name of the glucocorticoid secreted in rodents, birds, lizards and amphibians?

Answer 12

Corticosterone

Question 13

What is the name of the glucocorticoid secreted in primates, large mammals, carnivores and fish?

Answer 13

Cortisol

Question 14

What was found in ursin et al’s study on stress on military recruits?

Answer 14

Parachute jumps: testosterone was low immediately before and after the first jump- indicating a stress effect on the reproductive system

Question 15

What was found in the study on the burrow system in rats?

Answer 15

Dominant males had lower corticosterone and higher testosterone levels

Dominant animals appear to have higher levels of 12-beta-HSD which inactivates glucocorticoid

Question 16

What is different about dominant individuals in African wild dogs and dwarf mongooses?

Answer 16

Cortisol levels were higher in dominant individuals because they were involved in more aggressive encounters

Question 17

What did Levine et al hypothesise about stress and early experience?

Answer 17

Early stressful experiences influence stress responsiveness later in life