Endocrine L6: Stress Flashcards
(78 cards)
1
Q
What is stress?
A
“A state of mental or emotional strain or tension resulting from adverse or demanding circumstances”
2
Q
What is stress in terms of physiology?
A
the physiological responses of the body to stressful stimuli – ‘stressors’
- May be short-lived ‘acute’ response to a single traumatic event
- Can become ‘chronic’ if stressful situation persists or is prolonged
3
Q
What are the 2 types of physiological stress?
A
- May be short-lived ‘acute’ response to a single traumatic event
- can become ‘chronic’ if stressful situation persists or is prolonged
4
Q
When subjected to a stressor, the body responds to by adapting ______ function to cope
A
physiological
5
Q
What are stressors?
A
“any stimulus which causes a disruption of homeostasis leading to specific behavioural, endocrine and autonomic changes”
6
Q
What are 2 types of stressors?
A
- Psychological stressors
- Physical stressors
They differ slightly in their origins.
7
Q
What are psychological stressors?
A
stimuli which lead to fear, anxiety or frustration
8
Q
What are 3 characteristics of psychological stressors?
A
- includes traumatic events such as death, divorce, conflict, abuse, war and natural disasters
- can also include excitement, nervousness
- stimuli can be real or imagined (The response the body makes is the same as if it was real)
9
Q
What are physical stressors?
A
stimuli which disrupt normal body function, can be due internal factors or external environment
10
Q
What are 2 characteristics of physical stressors?
A
- hypoxia, hypoglycaemia, infection, physical strain (Even exercise can be a stressor), injury, starvation, dehydration
- exposure to heat or cold
11
Q
What are the 2 types of stress?
A
- Acute stress
- Chronic stress
12
Q
What is the response to acute stress?
A
a normal and beneficial adaptive response
13
Q
What are 4 characteristics o acute stress?
A
- Increases alertness and focus, provides energy to respond and cope with stressful situation
- The extent of the response is dependant on severity of stressor, and on the individual
- Mild stress improves mood, creates new memories, encourages creative thinking, promotes neural growth in brain, facilitates problem solving
- Severe stress can cause detachment, reduction in awareness, derealisation, depersonalisation, dissociative amnesia
14
Q
The extent of the acute stress response is dependant on ____ of stressor, and on the ____
A
severity; individual
People can behave different to stress (even if its the same situation)
15
Q
______ stress improves mood, creates new memories, encourages creative thinking, promotes neural growth in brain, facilitates problem solving
A
Mild acute
16
Q
______ stress can cause detachment, reduction in awareness, derealisation, depersonalisation, dissociative amnesia (People cant remember what the stressor or stressful environment was)
A
Severe acute
17
Q
_____ stress is healthy, only when it gets too much or too long that it is harmful (a real problem)
A
Mild
18
Q
What are 3 characteristics of chronic stress?
A
- When stress is prolonged or persistent, homeostasis is unable to be maintained
- The body enters an exhausted state, when damage to health can occur, immune suppression, hypertension, gastrointestinal disturbances
- Can have detrimental psychological effects - anxiety and mental dysfunction, social withdrawal
19
Q
What is the response to chronic stress be characterised as?
A
General Adaptation Syndrome
20
Q
What is General Adaptation Syndrome?
A
describes the stages of your bodies response to stress, three phases
21
Q
What are the 3 stages of General Adaptation Syndrome?
A
- Alarm (preparing to flight or fight)
- Resistance
- Exhaustion
22
Q
What is the “alarm” stage of General Adaptation Syndrome?
A
Preparing you for ‘fight-or-flight’, heightened alertness, energy mobilised
23
Q
What is the “resistance” stage of General Adaptation Syndrome?
A
stay alert (Tense state), but keep on with normal functioning (adaptation), homeostasis maintained
24
Q
What is the “exhaustion” stage of General Adaptation Syndrome?
A
resources are depleted, ‘burnout’ sets in, homeostasis cannot be maintained so function impaired, long term damage occurs
25
What does your body actually do in response to a stressor?
1. Tense
2. Increased HR
3. Focus (vision and hearing) --\> senses
26
What are 9 actions of the body as a response to the acute stress response?
1. Increased cardiovascular function - HR, contractility, mostly vasoconstriction (To rest to body to maintain blood pressure), with vasodilation to muscles (Large muscles that are needed for flight or fight)
2. Increased respiratory function - RR & TV, bronchodilation (Breath faster and breathe deeper = more efficient)
3. Liberation of nutrients - increased blood glucose & fatty acids (More available to be used)
4. Skin - paling or flushing, sweating, piloerection (Hairs stand on end)
5. Sensory - mydriasis (pupil dilation), auditory exclusion (Can only hear the important thing (can't hear anything else)), tunnel vision (Focus on what is going on (can't see anything else))
6. Muscle tension & shaking
7. Inhibition of gastrointestinal motility, contraction of sphincters (Focus energy and resources on muscles (more important))
8. Inhibition of the lacrimal gland and salivation
9. Relaxation of bladder, inhibition of erection
27
Stress is due to _____ and _____ responses
endocrine; nervous
28
What does a stressed cat look like?
29
The physiological responses to stressor are coordinated by the _______ system and involves both ________ and ______ system
hypothalamus; sympathetic nervous; endocrine
30
What are 3 characteristics of the sympathetic nervous system?
1. Adrenaline (epinephrine) from adrenal medulla
2. Noradrenaline (norepinephrine) from neurones
3. Inhibition of parasympathetic nervous system (Eg. GIT)
31
What are 4 characteristics of the endocrine system?
1. Cortisol & Corticosterone from adrenal cortex
2. Vasopressin (Anti-diuretic hormone- In kidney to retain water --\> increase fluid) from posterior pituitary
3. Activation of Renin-Angiotensin-Aldosterone system (‘RAAS’, involves liver, kidneys, lungs and adrenal cortex)
4. Insulin & Glucagon from pancreas
32
What hormone comes out of the medulla?
catecholamines (adrenaline, noradrenaline)
33
What hormone comes out of the cortex?
steroid hormones
34
Approx 80% of adrenal glands is \_\_\_\_\_\_\_.
cortex
35
What are the 3 layers of the cortex?
1. Zona glomerulosa
2. Zona fasciculata
3. Zona reticularis
36
What are the 4 different hormones involved with stress?
1. Corticosterone
2. Cortisol
3. Aldosterone
4. DHEA
37
Steroids synthesised from \_\_\_\_\_\_\_- huge variety, type produced is dependent on ______ availability
cholesterol; enzyme
38
What are mineralocorticoids: Aldosterone (adrenal cortex) produced in response to?
changes in ECF volume/blood pressure & stress (Blood volume gets too low)
39
What does mineralocorticoids: Aldosterone (adrenal cortex) promote?
water retention in kidneys by increasing Na+ reabsorption (More fluid in body = increase volume = increase blood pressure)
40
How much of Androgens: DHEA & Androstenedione (adrenal cortex) is produced?
both males & females, but in small quantities
41
What are Glucocorticoids: Cortisol & Corticosterone (adrenal cortex) produced in response to?
response to stress
42
What are 5 actions of Glucocorticoids (cortisol/corticosterone) in
1. Allows body to cope with stress by increasing availability of energy and amino acids
2. Increases vascular reactivity (by largely unknown mechanisms)
3. Affects mood & behaviour - improving mood, increasing alterness
4. Stimulates brain function - promotes neural growth in brain (Growth of brain cells = make you think better) which improves memory, creative thinking, problem solving ability
5. In chronic stress, may be responsible for immune suppression and other health defects
43
The adrenal medulla is part of the ______ nervous system
sympathetic
44
Medullary ‘\_\_\_\_\_\_\_’ cells are modified postganglionic neurones
chromaffin
45
Adrenal medulla produce the\_\_\_\_\_\_ adrenaline & noradrenaline in response to direct stimulation by sympathetic \_\_\_\_\_\_neurones from the splanchnic nerve
catecholamines; pre-ganglionic
46
In the adrenal cortex, hormones are released directly into the \_\_\_\_\_\_, and act on distant _____ tissues including heart, blood vessels, bronchioles, GIT
bloodstream; target
47
What does the sympathetic nervous system?
48
What are 5 functions of Adrenaline / Noradrenaline?
1. Elicits acute physical reactions of body to prepare for ‘fight or flight’
2. Increases cardiac & respiratory function (Increase HR and respiratory rate), slows digestion/kidney function, tenses muscles, increases sweating
3. Vasoconstriction to skin & organs (including kidneys) (Helps to increase pressure else where = i.e to the muscles which need it), vasodilation to skeletal muscles
4. Inhibits parasympathetic nervous system
5. Act on pancreas to reduce insulin secretion, increase glucagon secretion to increase blood glucose (Enough energy to respond to stress)
49
What is the summary table of the stress response?
50
All of the horomnes are controlled via the \_\_\_\_\_\_, responding to neural inputs stimulated by \_\_\_\_\_, and involve _____ gland & _____ glands
hypothalamus; stressor; pituitary; adrenal
51
What happens when you become over stressed?
* The extent and way in which individuals respond to a stressor varies greatly, influenced by personality, age, experience, support and coping mechanisms (Important to have a support network)
* Stress disorders can develop in response to severe life threatening events
* Chronic stress can cause immune suppression, weight loss, poor growth, hypertension, reproductive failure, mental disorders (depression, anxiety, stress disorders) and is associated with higher mortality
* Have experienced stress and haven't coped = worse
* Have experiences stress and have coped = better
52
What are the 2 ways that stress can be triggered?
1. Single traumatic event
2. Prolonged stress
53
People who are _____ (more/less) stressed tend to die more easily (eg. accident, injury, self harm)
more
54
What are stress disorders?
occur when stress response becomes recurrent in the absence of the stressor
55
What are 2 characteristics of Acute stress disorder (ASD)?
1. occurs after 2 days and within 4 weeks of original stressful event
2. dissociation, re-living of event (often nightmares), hyperarousal (including panic attacks), avoidance of reminders, impaired social functioning
56
What are 2 characteristics of post-traumatic stress disorder (PTSD)?
1. occurs after 4 weeks of original stressful event
2. dissociation, re-living of event (often nightmares), hyperarousal (including panic attacks), avoidance of reminders, impaired social functioning
57
What are 7 responses to chronic stress?
1. Immune suppression through excess glucocorticoid production, increasing risk of infection
2. Hypertension and cardiovascular disease – activation of RAAS & ADH, hyperlipidemia, hyperglycaemia (High fatty acids) & inflammation
3. Disruption of body weight - weight loss or obesity, redistribution of body fat
4. Poor growth in children through suppression of growth hormone production
5. Inhibition of parasympathetic nervous system can result in reproductive failure, poor digestion
6. Psychological disorders such as anxiety, depression, social withdrawal, increased substance abuse
7. Memory disorders
58
What are the chronic stress effects on the brain?
59
What are the 3 ways that prefrontal cortex and hippocampus respond to stress by?
1. Decrease existing nerves
2. Nerves get smaller
* Less branching
3. Loss of function
* This is reversible
60
What are the 4 ways that amygdala respond to stress by?
1. Increases response to stress
2. More nerves
* More branching
* Larger nerves
3. Hypersensitivity
4. This is irreversible
61
The stress response is coordinated by the _______ and involves both sympathetic nervous system and endocrine system, especially the ____ glands
hypothalamus; adrenal
62
In stress, major role for \_\_\_\_\_\_/\_\_\_\_\_\_ & glucocorticoids, with other hormones also involved
adrenaline/noradrenaline
63
Stress impacts on specific brain regions including \_\_\_\_, ____ and _____ cortex
hippocampus; amygdala; pre-frontal
64
Effects of stress can differ depending on \_\_\_\_\_, _____ and ____ of stressor, and differences between individuals
type; length; severity
65
Acute, severe and chronic stress all show different effects on \_\_\_\_\_\_\_
physiology
66
What is acute stress?
The acute stress response is a normal and beneficial adaptive response
67
What is mild stress?
Mild stress improves mood, creates new memories, encourages creative thinking, promotes neural growth in brain, facilitates problem solving
68
What does severe stress cause (single event)?
Severe stress can cause detachment, reduction in awareness, derealisation, depersonalisation, dissociative amnesia & result in stress disorders
69
What does prolonged/chronic stress?
Prolonged stress can damage health, causing immune suppression, hypertension, gastrointestinal disturbances, brain & psychological deficits
70
What are the 3 abnormalities of adrenal function?
1. Cushing’s syndrome
2. Adrenogenital syndrome
3. Addison’s syndrome
71
What is Cushing’s syndrome?
excess glucocorticoids: caused by increased ACTH from anterior pituitary, adrenal tumour or excess glucocorticoid administration (Can be used in medication)
72
What are 5 symptoms of Cushing’s syndrome?
1. Protein depletion – muscle weakness
2. Poor healing, immunodeficiency
3. Thin skin, prone to damage & hirsutism (Hairy)
4. Body fat redistribution & obesity
5. Insulin-resistant diabetes (Type II) (worsens pre-existing diabetes)
73
What does a pony with Cushing’s disease look like before and after treatment?
74
What is Adrenogenital syndrome?
excess production of androgens usually adrenal tumour
75
What are 4 symptoms of Adrenogenital syndrome?
1. Pre-pubertal males – precocious pseudopuberty (Can go into puberty very early --\> eg. 4 years old)
2. Adult males – no apparent effect!
3. Pre-pubertal females – pseudohermaphroditism (external genitalia appear male- Look like a male (external genetalia looks like male)
4. Adult females – virile characteristics, hirsutism (hairy), deep voice, increased muscularity, amenorrhea (Can become infertile)
76
What is the effect of Adrenogenital syndrome on males and females?
Males --\> not as damaging
Females --\> massive effect
77
What are Addison’s syndrome?
chronic failure of adrenal cortex
78
What are 6 symptoms of Addison’s syndrome?
1. Massive electrolyte imbalance - loss of aldosterone
2. Dehydration and hypotension (Not retain water = loss blood volume = lose pressure and become dehydrated) in response loss of glucocorticoids
3. ‘Addisonian crisis’ hypoglycaemia – coma, death! (averted if dietary intake sufficient)
4. Loss of vascular reactivity vasodilation/shock
5. Melanin pigmentation loss of negative feedback causes increased production of ACTH & melanocyte-stimulating hormone
6. People can die due to the lack of ability to cope with stress --\> go into an Addisonian crisis
7. Blood glucose drops = coma = die
