BP - Endocrine and fight or flight Flashcards
what is the role of the endocrine system
- supplements the work of the nervous system
- regulates cells and organs in the body
- network of glands throughout the body that manufacture and secrete chemical messengers
- use blood vessels to deliver hormones
what are hormones
chemical substances produced in a speciale gland and transported in blood to stimulate specific cells or organs into action
how do hormones work
- secreted from gland into bloodstream
- bind to receptors of target cells
features of the hypothalamus
- located in the brain
- stimulates and controls the release of hormones from the pituitary gland
features of the pituitary gland
- located in the hypothalamus
- posterior releases oxytocin
- anterior releases ACTH
- stimulates the adrenal cortex and release of cortisol during stress response
features of the pineal gland
- located in the brain
- releases melatonin
- responsible for biological rhythms like the sleep-wake cycle
features of the thyroid gland
- located in the throat/neck
- releases thyroxine
- responsible for regulating metabolism
features of the adrenal medulla gland
- located in the kidney
- releases adrenaline and noradrenaline
- responsible for fight or flight response
features of the adrenal cortex gland
- located in the kidney
- releases cortisol
- stimulates the release of glucose to provide the body with energy + suppress immune system
features of the ovaries
- located in the reproductive organs
- releases oestrogen
- controls regulation of the female reproductive system like menstrual cycle
features of the testes
- located in the reproductive organs
- releases testosterone
- responsible for muscle growth, male sex characteristics
how does the acute (sudden) stress response work
- the amygdala is mobilised when faced with a threat
- this sends a distress signal to the hypothalamus to release CRH
- the sympatheticNS is triggered by the hypothalamus which increases bodily action
- this stimulates the adrenal medulla
- the adrenal medulla releases adrenaline so breathing and heart rate increase
- when the threat has passed , the parasympatheticNS is activated so return the body back to normal
how does the chronic stress response work (HPA AXIS)
- body tries to fight the stress with adrenaline to no avail
- if the threat is still there the secondary response is activated
- hypothalamus releases more CRH into the bloodstream
- ACTH is released into the blood by the pituitary gland as a secondary stress response
- this stimulates the adrenal cortex to release cortisol
- cortisol gives you more energy
- feedback system is engaged to cortisol levels are measured
what happens in the feedback loop during the chronic stress response
if cortisol is too high, CRH and ATCH production is inhibited so cortisol will stop being released
what are the effects of cortisol
- causes brain fog
- increase in pain tolerance
- suppresses immune system
AO3: X Von Dawans et al (2012) challenge…
the view that mend respond with fight or flight but women respond with tend and befriend.
says EVERYONE can have more cooperative behaviour under acute stress (not just women)
AO3: X individual differences may include a genetic basis for different responses…
to stress as some people may thrive in stress whereas others hate it
the SRY gene found only on male Y chromosomes promotes the fight or flight response
AO3: X the freeze response
this is where a person does not fight or flight is response to stress - adaptive advantage to animals with predators
AO3: X it is unhelpful in the modern day
humans experience lots of stress on a day to day basis that does not require more energy to avoid the stress
can cause heart disease by constantly putting stress on blood vessels
