The physiology of stress

Question 1

What is stress?

Answer 1

An emotional response to situations of threat.

Question 2

What can the threats be in stress?

Answer 2

May be physical or psychological.

Question 3

What responses can be produced?

Answer 3

Whether stress is physical or psychological your body produces a short term/immediate response and if it continues the stressor continues a long term/ongoing response.

Question 4

What happens when faced with a stressful situation?

Answer 4

Can produce a immediate response of the fight or flight.

Question 5

What is the short term response to stress called?

Answer 5

Sympathomedullary pathway/SAM system

Question 6

What happens in the S part of the SAM System?

Answer 6

The sympathetic nervous system is activated by the hypothalamus and the stressor is perceived.

Question 7

What happens in the M part of the SAM system?

Answer 7

A signal is sent to the central nervous system to two endocrine glands above the kidneys. The adrenal medulla releases adrenaline and smaller amounts of noradrenaline.

Question 8

What happens in the A part of the SAM system?

Answer 8

The adrenaline and noradrenaline circulate through the body and affect key target organs which cause the heart to beat faster and blood pressure to rise which makes the animal more prepared to deal with the threat.

Question 9

What happens when a threat has passed?

Answer 9

The parasympathetic branch of the autonomic nervous system dampens down the stress response so the body can return to a normal state.

Question 10

What is the response to long term stressors?

Answer 10

It’s a slower response known as the hypothalamic pituitary-adrenal system (HPA axis).

Question 11

What is the hypothalamic pituitary-adrenal system?

Answer 11

Parts of the brain & body that are involved in long term stress response involving cortisol.

Question 12

What happens in the H part of the HPA axis?

Answer 12

The hypothalamus releases corticotropin releasing hormone into the blood stream.

Question 13

What happens in the P part of the HPA axis?

Answer 13

CRH causes the pituitary gland to produce and release adrenocortropic hormone (ACTH) into the blood stream.

Question 14

Whay happens in the A part of the HPA axis?

Answer 14

The ACTH stimulates the adrenal cortext which releases other stress related hormones like cortisol which has some positive effects (lower sensitivity to pain and burst of energy) and some negative (lowered immune response).

Question 15

What did Selye’s (1930) research lead him to conclude?

Answer 15

Led him to conclude that when animals are exposed to a stimulus they display a universal response to all stressors and has 3 stages.

Question 16

Why is the GAS syndrome general?

Answer 16

The same response produced to all agents.

Question 17

Why is the GAS system adaptive?

Answer 17

As the animals adapt to the best way to cope with stress.

Question 18

Why is the GAS system a syndrome?

Answer 18

As there are several symptoms in the stress response.

Question 19

What is stage 1?

Answer 19

Alarm reaction.

Question 20

What happens in stage 1?

Answer 20

1) Threat is recognised
2) The hypothalamus is triggered and so is the production of adrenaline/noradrenaline
3) Hormones lead to the readiness of the fight or flight response

Question 21

What is stage 2?

Answer 21

Resistance.

Question 22

What happens in stage 2?

Answer 22

1) If stress continues the body tries to find ways to cope
2) The body is adapting to the demands of the environment but resources (hormones, sugaras etc) are being depleted
3) The body appears to be coping but it deteriorating and the immune system is compromised.

Question 23

What is stage 3?

Answer 23

Exhaustion.

Question 24

What happens in stage 3?

Answer 24

1) The body can no longer maintain normal functioning.
2) Symptoms of adrenaline response may reappear.
3) The adrenal glands may be damaged from previous over activity and the immune system may not be able to cope as the production of necessary proteins has been slowed.
4) May lead to stress related illnesses, ulcers, depression, cardiovascular problems and mental/physical illness.