fight or flight and endocrine system Flashcards
the endocrine system what does it do?
- supplements work of nervous system
- regulates cells and organs in body
- it’s a network of glands through body that manufacture and secrete chemical messengers (hormones)
- uses blood vessels to deliver hormones to target site in body
difference to nervous system?
- acts slower and operates all over body than nervous system and has more long term powerful responses
hormones what are they and summarise process?
- produced in specialised gland in endocrine system
- chemicals are circulated in bloodstream and carried to target sites through body.
—> affect target cells (have necessary receptors for that hormone)
—> when enough receptor sites stimulated by hormone= physiological reaction in target cell
how do hormones work
- secreted by gland —> passed through blood stream until reach destination —> bind to receptors in target cell specific to hormone —> cell responds according to its function
what is the command centre for the endocrine system?
the hypothalamus (in the brain) which is in the limbic system
it ensures messages sent through nervous system to tell different glands whne to release hormones
what does the hypothalamus have direct control of?
- direct control of pituitary gland which secretes lots of different hormones and is located in hypothalamus
- pituitary gland produces hormones that travel in bloodstream to target site= either causes change or stimulates other glands to release hormones
—> negative feedback stops hormone levels rising too high
what’s the master gland?
pituitary gland
what are endocrine glands?
- produce and secrete hormones
- each gland produces different hormones that regulate organs and tissues in the body
- many glands operate on basis of a feedback loop
what is the fight or flight
helps individuals react quick to stressful/threatening situation
- heart beats faster, breathing quicker, muscles tense etc
- survival mechanism in life threatening situations but may also occur in non-life threatening!
summary of acute stress response
amygdala—> hypothalamus —> CRH —> SNS —> adrenal medulla releases adrenaline—> PNS
acute sudden stress response steps.
- Amygdala associates sensory signals with emotions like fear and anger = sends distress signal to hypothalamus
- hypothalamus in rekindle to threat releases CRH into bloodstream
- sympathetic nervous system (SNS) prepares body for rapid action
- adrenal medulla releases adrenaline go bloodstrem= physiological changes e.g. up heart rate, release of blood sugar etc
- adrenaline released= increases blood pressure, heart beat, breathing, glucose to blood stream etc
- once threat has passed the most parasympathetic nervous system (PNS) slows down the stress response
what happens if the stress or threat is still there
chronic stress response
stages of chronic stress response
- 2nd system (HPA axis) kicks in after acute sudden response
- HPA axis sends signals to hypothalamus which indicates stress is still there so releases more CRH into bloodstream to target sites
- pituitary gland releases ACTH to bloodstream and to its target sites
- adrenal cortex releases stress hormones (cortisol) in response to stress
- feedback system. Cortisol levels are so monitored so CRH and ATCH production is inhibited if cortisol too high
BUT if threat still there then whole stress response occurs again so cortisol will increase again
chronic stress response summary
HPA axis —> hypothalamus—> CRH —> adrenal cortex —> cortisol —> feedback system
in chronic stress response what’s the impact of the release of the hormone cortisol on us?
- makes us energised
- shakey
- weakens immune system
- brain fog
- lower severity of pain
- impairs cognitive performance
eval point 1
- Taylor et al suggested women behavioural responses to stress is more characterised by pattern of ‘tend or befriend’ rather than fight or flight
—> protecting young and themselves through nurturing (tend) and forming protective alliances with women (befriend)
—> suggests women may have diff system for coping with stress as responses evolved from being primary caregiver or child as fleeing in danger would put offspring at risk - influence of individual differences (gender)
BUT now not helpful as mother not always primary caregiver
eval point 2
- stressors of modern life rarely requires such high levels of physical activity —> high blood pressure etc unnecessarily can damage blood vessels and cause heart disease and too much cortisol suppressed immune system and increase likelihood of stress related illness etc
eval point 3
- Grays suggested there’s also a ‘freeze’ response which has advantages such as makes humans focus attention and look got new info before responding to threat
eval point 4
- Van Dawans found acute stress can lead to greater co-operative and friendly behaviour in men and women —> explains human connection in crisis such as 9/11 terrorist attacks —> protective nature of human social relationships allowed species to thrive
eval point 5
- Harley and Lee found evidence of a genetic basis for gender differences in fight or flight response
—> SRY gene which is from the Y chromosome directs male development and promotes aggression = fight and flight response to stress —> SRY gene in men releases adrenaline —> females who don’t have SRY gene may therefore prevent this response to stress and ‘tend and befriend’ behaviours instead
endocrine glands: hypothalamus, pituitary, pineal
hypothalamus- in brain, stimulates and controls release of pituitary gland
pituitary gland- in brain, posterior (back) releases oxytocin and anterior (front) releases ACTH which stimulates the production of cortisol
pineal gland - in brain, release melatonin which is a key hormone in sleep-wake cycle and biological rhythms
endocrine glands: thyroid, adrenal
thyroid- in neck, releases thyroxine which is responsive for metabolism
adrenal- adrenal medulla releases adrenaline (key for fight or flight) and adrenal cortex releases cortisol which stimulates release of glucose= energy for body and suppresses immune system etc
endocrine glands: ovaries, testes
ovaries- reproductive organs which release oestrogen and are key in the menstrual cycle and pregnancy
testes- reproductive organs which releases testosterone and is key for muscle growth and male sex characteristics
