The flight or fight response Flashcards
what does the amygdala do?
when an individual is faced with a threat the amygdala is mobilised
it sends sensory signals with emotions associated with F&F such as fear/ anger
it then sends a response to the hypothalamus - the command centre which communicates with the rest of the body through the sympathetic branch
what does the sympathetic branch do in the F&F response?
it begins the process of preparing the body for the flight or fight response
it sends a signal to the adrenal medulla which responds by releasing adrenaline through the bloodstream
what does adrenaline do in the flight or fight response?
it causes physiological changes
heart beats faster - pushing blood to the body
breathing fastens to take in more oxygen
pupils dilates
bronchi dilates
what does the parasympathetic nervous system do?
when the threat has passed, the PNS dampens down the stress response
the parasympathetic nervous system slows down the heartbeat and reduces blood pressure
What is the body’s response to ongoing stress?
The second system kicks in as the initial surge of adrenaline subsides, the hypothalamus activates a stress response signal called the HPA axis which consists of the hypothalamus, the pituitary gland and the adrenal glands
What does the H stand for in the HPA?
The hypothalamus
the HPA axis relies on a series of hormonal signals to keep the SNS working. In response to the continued threat, the hypothalamus releases a chemical messenger corticotrophin-releasing hormone (CRH) which is released into the bloodstream
What does the P stand for in HPA?
On arrival at the pituitary gland, CRH causes the pituitary gland to release adrenocorticotrophic ACTH
from the pituitary ACTH is transported in the bloodstream to its target site in the adrenal gland.
What does the A stand for in the HPA
ACTH (adrenocorticotrophic) stimulates the adrenal cortex to release various stress related hormones including cortisol. Cortisol is responsible for several effects in the body that are important for the flight or right response. Some of these are positive (quick burst of energy/lower sensitivity for pain) whereas some of these are negative ( impaired cognitive performance and a lower immune response
Is this response effective
It is an efficient self regulating process. Both the hypothalamus and pituitary gland have special receptors that monitor circulating cortisol levels. If these rise above normal, they initiate a reduction in CRH and ACTH levels thus bringing back cortisol levels back to normal
