2. The body responds to stress by means of two different pathways
1. The pituitary-adrenal system
The body's response to CHRONIC stress - also known as HPA
(hypothalamic-pituitary-adrenal)
This pathway is activated when higher brain centres evaluate a situation as
being stressful. These higher brain centres instruct the hypothalamus to
release corticotrophin releasing factor (CRF), which travels to the pituitary
gland. CRF causes the pituitary gland to release adrenocorticotrophic
3. hormone (ACTH) into the bloodstream. ACTH travels to the adrenal cortex and
stimulates the release of corticosteroids into the bloodstream. These
corticosteroids have a variety of effects throughout the body and form part of
the stress response.
4. 2. The Sympathomedullary Pathway
The body's response to ACUTE stress - also known as SAM (sympathetic
adrenal-medullary)
The stressor activates the hypothalamus which activates the sympathetic
branch of the autonomic nervous system (ANS). Nerves from the ANS travel to
the internal organs and glands in the body. The ANS causes the adrenal
medulla to release the hormones adrenaline (epinephrine) and noradrenaline
(norepinephrine) into the blood. These hormones create changes in the body
which prepares the individual for fight or flight. After the threat has
