block 6 lecture 6 Flashcards
what is stress?
any condition that poses a challenge to the bodies ability to maintain homeostasis
what is good stress called?
eustress
what is eustress for?
good stress that prepares you for challenges
what is bad stress called?
distress
what is a stressor?
any stimulus that produces a stress response
what are the 4 types of stressors?
internal, external, psycological, physiological
what are the types of external stress?
physical environment social interactions organisational major life events daily hassels
what are some examples of internal stress?
lifestyle choices
negative self critic
mind
personality traits
what is general adaptation syndrome?
physiological response to stressors to maintain homeostasis
what are the 3 main stages of stress response?
alarm phase
resistance
exhaustion
what is the pathway of the short term stress response?
stress - cerebral cortex - hypothalamus - sympathetic nervous system - adrenal medulla - catecholamines
what is the pathway of the long term stress response?
stress - cerebral cortex - hypothalamus - pituitary gland - adrenal cortex - glucocorticoids
what are the catecholamines in the short term stress response?
adrenaline and noradrenaline
what are the glucocorticoids in the long term stress response?
cortisol
how is the alarm phase characterised?
short lived, rapid action, activates sympathetic nervous system
what are the sympathetic nervous system responses to stress in the alarm phase?
glycogen > glucose in the liver/ increases metabolic rate/ increases blood pressure/ blood is diverted to the skeletal system/ dilation of airways/ alertness increased/ sweating
what does long term stress activate?
HPA axis
what do neurosecretory cells in the hypothalamus secrete?
CRH
what does CRH activate?
the anterior pituitary gland
what does the anterior pituitary gland secrete?
ACTH
where does the ACTH go from the pituitary gland?
travels in the blood to the adrenal gland
what does ACTH do?
stimulates cells in the adrenal cortex to release cortisol
what does cortisol do?
glucose is synthesized from lipids and amino acids,
other than cortisol what is released by the adrenal glands in the long term stress response?
aldosterone
what does aldosterone do?
retention of sodium, retention of water, increased blood pressure
what does the long term stress response do to the immune system?
suppresses it
what happens in exhaustion phase?
resources of the body become so depleted they cant sustain resistence phase
what happens during prolonged exposure to high levels of cortisol?
muscle breakdown, suppression of the immune system, ulcers in GI tract, depression, failure of pancreatic beta cells, aging
what is the amygdala involved with?
fear response
what is activated in the amygdala to produce a stress response?
activation of the central nucleus
what regulates the CRH neurones in the hypothalamus?
amygdala and the hippocamus
what does amygdala activation stimulate?
HPA axis and stress response
what does hippocampal activation do?
suppresses HPA axis
what events are remembered better?
emotional
what does injecting cortisol do?
enhances memory?
what reduces memory?
propanolol and amygdala lesions
what can acute stressors do to the immune system?
upregulate
what does cortisol do to the immune system?
reduces the number of T and B cells
