What is the definition of a stressor?

What is particularly important about the definition?

What is the definition of a stressor?

What is particularly important about the definition?

- a stressor is anything (physical or psychological insult) that disrupts physiological homeostasis

- individual perception is important

Describe what was done and what was directly observed in Hans Selye's stress response experiment.

- rats injected with ovarian extracts

- rats developed peptic ulcers, enlarged adrenals, and shrunken immune tissue

In Hans Selye's stress response experiment, were the results caused by a hormone?

Why or why not, and if not then what was the cause?

In Hans Selye's stress response experiment, were the results caused by a hormone?

Why or why not, and if not then what was the cause?

- No, not caused by hormone

- can't be since same symptoms were in the controls

- stress was causing it

What 3 things stimulate the sympathetic nervous system?

arousal

vigilance

emergency

What type of functions are mediated by the parasympathetic nervous system?

Give 4 examples.

What type of functions are mediated by the parasympathetic nervous system?

Give 4 examples.

calm vegetative functions:

growth

digestions

slow heart rate

slow breathing

What is the first phase of the stress response? What arm is this?  What is its approximate response time?  Which gland (and which part of it) releases the hormones for this?  What class of hormones are released?  Which 2 specific hormones?

- Fight-or-Flight (the fast arm -- caused by SYMPATHETIC NS)

- ~3-5 seconds

- Medulla of the adrenal gland releases catecholamines:

- adrenaline (epinephrine)   &

noradrenaline (norepinephrine)

What is the 2nd phase of the stress response?  Which arm of the stress response is this and what is another term for it?  Approximate response time?

Which gland/part of gland releases hormones?  What class is released and what specifically is released?

What is the 2nd phase of the stress response?  Which arm of the stress response is this and what is another term for it?  Approximate response time?

Which gland/part of gland releases hormones?  What class is released and what specifically is released?

- Adrenal activation: slow arm / General Adaptation Syndrome

- ~3-5 minutes

- Cortex of adrenal gland releases glucocorticoids:

*Cortisol (all mammals except rodents)

*Coricosterone (rodents, reptiles, birds)

The stress response is non-________.

Magnitude of ___ related to magnitude of ___.

What has the historical opinion been about the stress response?

The stress response is non-specific.

Magnitude of response related to magnitude of stressor.

What has the historical opinion been about the stress response?

- was thought to be adaptive

What are some logical features of the stress response?

- mobilization of energy

- increased heart rate and blood pressure

- suppression of digestion, growth, reproduction, immunity, and inflammatory response

- analgesia

- altered perception & cognition

When is the stress response no longer adaptive?

When:

1) long term stressor

2) frequent stressor

3) psychological stressor

leads to

stress related disease

Does stress make you sick?

No, it makes you more likely to get the diseases that make you sick

What example was given of something we get stressed out about?  What 2 hormones had spiked levels near when this event happened?

- exams

- epinephrine & norepinephrine

When does stress-related disease often appear?

- when stress response activated for too long or too frequently &

when it is not activated for physiological reason (eg, psychological or social stresses)

The pathology of stress probably results from what?

long-term exposure to stress hormones

Metabolic stress-response: when body not stressed, insulin fxns normally. what does this entail?

- promotes glucose uptake & fatty acid synthesis

- blocks breakdown of triglycerides

- in muscles, = glucose & AA transport, glycoen & protein synthesis, AND blocks their breakdown

- in liver, = formation of glycogen & blocks breakdown

The metabolic stress-response:  when body IS stressed, describe insulin's situation.

- secretion is inhibited

- storage of substrates is stopped

- energy stores are mobilized

The metabolic stress-response:  which 3 hormones are released during stress & what effects to they cause?  How do these compare to insulin's normal effects?

- E, NE, and glucocorticoids

- cause lipolysis, glycogenolysis, & proteolysis

- direct contradiction to normal insulin effects

What 3 ways does chronic activation of the metabolic stress-response cause disease?

What 3 ways does chronic activation of the metabolic stress-response cause disease?

- myopathy (breakdown of muscles)

- weakness

- fatigue

The cardiovascular stress-response:  what happens to cardio tone? Why? What other 4 factors are increased? What one decreases?

- tone increased:  to deliver more of the mobilized glucose & oxygen to the tissues that need it

- increase in: breathing rate, heart rate, blood pressure, & blood volume (via water retention)

- decrease in blood flow to some organs

What (specifically) results from chronic activation of the cardiovascular stress-response?  These things lead to which 2 conditions?

- heart muscle damage

- vessel walls weakened

- cholestoral and plaques deposited

- leads to:  Hypertension & Heart disease

Prolonged stress leads to gastric ulcers BUT

- The stomach usually... ____

- Ulcer repair is usually...

- Also, what is one other thing that can be a factor compromising the stomach lining's self-repair ability

Prolonged stress leads to gastric ulcers BUT

- The stomach usually... spends energy repairing stomach mucosa (not w/ stress)

- Ulcer repair is usually... facilitated by prostaglandins (which are inhib.ed by stress)

- Also, what is one other thing that can be a factor compromising the stomach lining's self-repair ability

- the bacteria Helicobacter pylori also compromises stomach lining's ability to repair itself.