Lecture 1 Block 3 Flashcards
(25 cards)
define psychological stress
a feeling of strain and pressure on the mind
define physiological stress
a real strain on the body
what is a stressor
a physical, chemical, or psychological factor resulting in tension of the body or mind
what are the 4 stress responses of the body
- sympathetic activation in 2-3 seconds
- adrenal activation in 20-30 seconds
- HPA axis activation in minutes, days, or hours
- cortisol negative feedback surpasses stress response
how is sympathetic activation communicated
by electrical activity of the sympathetic nerve
what happens in sympathetic activation
release of NE directly on target organs
what are the results of sympathetic activation
- increased HR, vasoconstriction, and sodium water retention lead to higher BP an better circulation to skeletal muscle,
- glycogenolysis and gluconeogensis and lipolysis make more nutrients available
- bronchial dilation results in more O2 intake
- pupil dilation allows more sensory information to be sent to the brain
- reduced digestion and bladder relaxation direct resources and attention to the stressor
what type of innervation is the sympathetic innervation of blood vessels of skeletal muscle
cholinergic
what happens in adrenal activation
sympathetic nerve activates adrenal medulla to release epinephrine into blood circulation
what is the difference between epinephrine and norepinephrine
has same adaptive effects as norepinephrine but norepinephrine weans quickly and epinephrine lasts longer
what are the two “molecules” that facilitate HPA axis activation
glucocorticoids and mineralocorticoids
what do glucocorticoids do
break down proteins, fatty acids and glycogen; glycogenesis, vasoconstriction, immunosuppression
what do mineralocorticoids do
sodium and water retention to increase blood pressure and blood volume
what is the purpose of HPA axis activation
not meant to extend stress response, but glucocorticoids increase the breakdown of muscle protein which in long term will weaken fight or flight responses
what do sympathetic activity and epinephrine prevent
breakdown of muscle protein
what does an adrenalectomy do
removes cortisol release and increases sympathetic activity
what is the pathway of cortisol release
hypothalamus -> CRH - > anterior pituitary -> ACTH -> adrenal cortex -> cortisol -> target tissue -> response
what role does the sympathetic nervous system play in the stress response
the initiator- rapid and adaptive
what role does the adrenal medulla play in the stress response
releases epinephrine, the reinforcement, to keep the response going
what roles does the HPA axis play in the stress response
- provides metabolic support for stress responses
- provides metabolic support for repair and building
- ends stress response when the stressor is neutralized-terminator
- re-gains homeostasis and returns the system to its normal state
what are the mental symptoms of PTSD
- avoidance
- intrusive memories
- cognitive and mood disorders
- changes in physical and emotional reactions
what are cortisol and E/NE levels like in normal acute or chronic stress responses
they are all elevated
what are cortisol, CRH, and E/NE levels like in PTSD
E/NE and CRH levels are elevated but cortisol is reduced
what are some genetic influences in PTSD
- monozygotic twins have significant higher concordance for PTSD than dizygotic twins
- genes associated with HPA axis are associated with PTSD
