L6 Stress Flashcards
Define stress (physiology definition)
the physiological responses of the body to stressful stimuli
define stressor
any stimulus which causes a disruption of homeostasis leading to specific behavioural, endocrine and autonomic changes
name and define the two types of stressor
psychological stressors: stimuli which lead to fear, anxiety or frustration (includes traumatic events such as death, divorce, conflict, abuse, war and natural disasters; can also include excitement and nervousness; stimuli can be real or imagined)
physical stressors: stimuli which disrupt normal body function, can be due to internal or external factors
- internal factors: hypoxia, hypoglycaemia, infection, physical strain, injury, starvation, dehydration
- external factors: exposure to heat or cold
define acute stress
the acute stress response is a normal and beneficial adaptive response
benefits of acute stress
increases alertness and focus and provides energy to respond and cope with stressful situations
results of mild stress
improves mood, creates new memories, encourages creative thinking, promotes neural growth in brain, facilitates problem solving
results of severe stress
detachment, reduction in awareness, derealisation, depersonalisation, dissociative amnesia
define chronic stress
when stress is prolonged or persistent, homeostasis is unable to be maintained (disrupting bodies ability to function normally)
what happens to the body during chronic stress (physically and psychologically)
physical - the body enters an exhausted state, when damage to health can occur, immune suppression, hypertension, gastrointestinal disturbances
psychological - anxiety, mental dysfunction, social withdrawal
what is general adaptation syndrome
describes the stages of your bodies response to stress
what are the stages of general adaptation syndrome
- ALARM: preparing you for ‘fight-or-flight’, heightened alertness, energy mobilised
- RESISTANCE: stay alert but keep on with normal functioning (adaptation), homeostasis (maintained)
- EXHAUSTION: resources are depleted, ‘burnout’ sets in, homeostasis cannot be maintained so function impaired, long term damage occurs
which of these could be considered a physical stressor?
a. anxiety
b. hypoglycaemia
c. frustration
d. excitement
B
what does the acute stress response do to your body?
- increased cardiovascular function: HR, contractility, mostly vasoconstriction, vasodilation to muscles, increase blood pressure
- increased respiratory function: respiratory rate and total volume, bronchodilation
- liberation of nutrients: increased blood glucose and fatty acids
- skin: paling or flushing, sweating, piloerection
- sensory: mydriasis (pupil dilation), auditory exclusion, tunnel vision
- muscle tension and shaking
- inhibition of gastrointestinal motility, contraction of sphincters
- inhibition of the lacrimal gland and salvation
- relaxation of bladder, inhibition of erection
the physiological response to stress are coordinated by the ________ and involves both ________ and _______ systems
the physiological response to stress are coordinated by the HYPOTHALAMUS and involves both SYMPATHETIC and ENDOCRINE systems
what happens to the following when a stressor occurs?
- posterior pituitary
- anterior pituitary
- sympathetic nervous system
posterior pituitary = increase vasopressin (helps to retain fluid in your body = retain water or reabsorbs water back from your urine = increase fluid = helps keep up blood pressure)
anterior pituitary gland is stimulated by corticotrophin releasing hormone = increases ACTH = affects adrenal cortex to release cortisol
sympathetic NS acts on the adrenal medulla to produce epinephrine (adrenaline)- also effects:
- arteriolar system: vasoconstriction in arteries = decreases blood flow through kidneys = decrease filtration rate and response from RAAS (increase renin, increase angiotensin, increase aldosterone) systems
- pancreas responds by increasing glucagon and decreasing glucose to release more energy from the energy stores
