Stress Physiology Flashcards
what are the main definitions of stress
- to emphasise certain words in speech
- a force applied to a body causing deformation or strain
- emotional or mental pressure
what are physical stressors
injury
surgery
infection
pain
exposure to cold
sustained exercise
what are threatening stressors
imprisonment, torture
what are the body systems that interact with each other during stress
nervous
endocrine
immune
what do the stress effects depend on
duration and severity of the stressor, and the effectiveness of any responses
what is involved in the alarm reaction
fight, flight or fright response
physiological effects
what occurs in the resistance phase
adapting to stressors
what occurs in the exhaustion phase
occurs when there is severe, persistent stress
responses are futile, and systems fail
there are pathological effects
describe the steps to the general adaption syndrome
alarm reaction
resistance phase
exhausation phase
what is the benefit associated with small levels of stress
increased attention and learning
what is the alarm reaction
this is the acute stress response including fight of flight
it is a physiological resopnse to a physical threat
neurological control from the sympathetic nervous system
hormonal control from the adrenal glands
describe the hormonal control of the acute stress response
adrenaline and corticosteroids
which gland produces corticosteroids
adrenal cortex
what is the gland that produces adrenaline
adrenal medulla
describe the impact of the alarm reaction on the cardiovascular system
increased cardiac output and redistribution of cardiac output
describe how he alarm reaction increases cardiac output
increased heart rate and ventricular contraction
describe how the alarm reaction redistributes cardiac output
increases flow to muscle and decreases the flow to the gut and kidney
describe the metabolic impact of the alarm reaction
glycogen breakdown leads to glucose release
there is mobilisation of fat stores to release fatty acids
describe why adrenaline is released in the alarm reaction
it releases augments and prolongs the action of the sympathetic nerves
increases cardiac output
redistributes cardiac output
has metabolic effects
describe the impact of glucocorticosteroids in the alarm reaction
cortisol is the main stress hormone and its actions complement the SNS and adreanline
can have harmful impacts when the secretion is high
what is the main stress hormone
cortisol
describe the metabolic action of cortisol
increased energy production from glucose, amino acids and fats
increases protein breakdown
what is the permissive effect of cortisol
enhances the action of adrenaline
what are the four main actions of cortisol
metabolic
enhance adrenaline
anti inflammatory actions
immunosuppression
how do glucocorticosteroids have immunosuppressant actions
they inhibit the release of prostoglandinds and leukotrienes, and they inhibit macrophages and helper t cells
why do some people take cortisol
as anti inflammatories
it suppresses CRH and ACTH release to suppress the natural stress response
describe the endocrine pathway of cortisol release
stress detected by hypothalamus, which releases corticotropin releasing hormone to the anterior pituitary
this releases adrenocorticotrophic hormone to the adrenal cortex
this releases cortisol
when is pain diminished
during physical stress like in sports and in battle
what is stress analgesia
this is when pain gets diminished during high stress situations due to the release of endogenous opioid peptides, endorphins, and enkepahlins
they suppress nociception and pain
how is stress assessed
by changes in blood pressure and heart rate
do women or men have greater responses to stress
women have greater heart rate changes, but they both have equal blood pressure
how does systolic blood pressure change during stress
increases from 5-20mmHg
how does diastolic blood pressure alter during stress
increases by 4-8mmHg
describe how heart rate changes during stress
up to 20 beats per minute
when are stress responses in dentists greater
when standing
during complex procedures
when patients are anxious
describe the adaptation phase in detail
after there is persistent exposure, the stress response diminishes and the individual has adapted.
this means the stressor is no longer a threat
this happens if the indiviaduals responses are effective in removing the stressor is there is a perceived threat
what happens if there is a failure to adapt to stress
adrenal failure
immunosuppression
peptic ulcers
CVS disease
describe type A individuals
these are hard driving, competitive individuals that are more prone to high blood pressure
what are type B individuals
these are those who are more relaxed and less impatient
