Stress as a Bodily Response

Question 1

What is a stressor?

Answer 1

Any event, situation or object that causes a stress reaction in the body.

Question 2

What are the two separate divisions of the autonomic nervous system?

Answer 2

• Sympathetic Branch

* Parasympathetic Branch

Question 3

Explain the process by which the sympathomedullary pathway is triggered and what happens after it is triggered.

Answer 3

1. A stressor is perceived by the hypothalamus
2. It activates the sympathetic branch of the autonomic nervous system
3. This causes the adrenal medulla to release adrenaline and noradrenaline into the blood stream
4. These hormones increase heart rate and blood pressure which helps to mobilise energy resources quickly
5. Oxygen is also mobilised to the muscles as part of the ‘fight or flight’ response

Question 4

Explain the process by which the Hypothalamic Pituitary-Adrenal System is triggered and what happens once it is triggered.

Answer 4

1. The hypothalamus stimulates the pituitary gland by sending a chemical messenger
2. The pituitary gland releases a stress hormone ACTH into the bloodstream
3. This travels to the adrenal cortex and stimulates the release of corticosteroids like Cortisol
4. Cortisol helps release glucose from the liver, it assists the conversion of stored fat into energy and suppresses the immune system

Question 5

What is the parasympathetic branch?

Answer 5

It is the counter reaction to the ‘fight or flight’ response. It occurs a few minutes after the danger/stressor has subsided. It is sometimes referred to as ‘rest & digest’, as it decreases oxygen consumption, lowers blood pressure, slows down the heart rate and relaxes muscles.