What is stress?
a state of heightened arousal
-it comes in many forms and for many reasons; but all of them have in common a set of mechanisms known as the stress response
Eustress
-moderate or normal psychological stress interpreted as being beneficial for the experiencer
Distress
aversive state in which a person is unable to completely adapt to stressors and their resulting stress and shows maladaptive behaviors
Physiological stressors
arise when homeostasis control mechanisms are challenged (physcial, chemical, biological, social, cultural)
psychological stressors
are whatever the person thinks they are
What are some general effects of stress?
- trigger certain illnesses
- reduces the body’s ability to fight an illness
- make some diseases harder to control
Homeostasis
aims to maintain “a set point” of bodily functions
ex: oxygen level, pH, blood pressure
Allostasis
aims to maintain a “set point” in changing environments
General adaptation syndrome
general stress response to any noxious stimulus
-includes 3 stages
What are the 3 stages of GAS?
- Alarm reaction
- Stage of resistance
- Stage of exhaustion
What happens in the alarm reaction?
Fight or flight response
What happens in the stage of resistance?
adaptation, body returns to homeostasis
What happens during the stage of exhaustion?
Not able to return to homeostasis
What is the function of the hypothalamus in the GAS?
- Monitor of internal and external environment
- activate GAS
- secretes corticotrophin-releasing hormone (CRH)
What parts of the body do CRH affect?
- The sympathetic nervous system which affects the inner portion of the adrenal medulla
- the pituitary gland which affects the outer portion of the adrenal medulla
Function of catecholamines and examples
- sympathetic activation
- norepinephrine
- epinephrine
Function of cortisol and related glucocorticoids
pituitary gland affects the adrenal medulla which has metabolic effects
Risk factors
tendencies that promote the development of the disease
your patient’s red blood cell is slightly elevated today. This might be explained by
- gender difference
- situational factors
- illness
What is the etiology of strep throat
-streptococcal infection
Charlie’s hand is tangled in a rope, cutting off blood flow to his hand. At what time are the cells from Charlie injured
- ischemia
- reperfusion
- any injury longer than a minute causes
A hypoxic injury is caused by a lack of
ATP
You are asked to participate in a research project on myocardial infractions in a rat model. Which model closely represents the ischemic injury?
Increase of intracellular concentration of Na+ and Ca++
Which of the following is not a change experienced by typical cells undergoing apoptosis?
Membrane bursting
What is a physiological effect of chemical stress mediators:
catecholamine
What are the two main subsets of catecholamine receptors?
-alpha-adrenergic and beta-adrenergic receptors
What do agonsists do?
mimics alpha or beta-adrenergic recpetors used in disease state
What do antagonists do?
-block alpha- or beta-adrenergic receptors used in disease state
alpha 1 receptors site of actions
- smooth muscle
- heart
- liver
alpha 2 sites of action
-platelets, vascular smooth muscle, nerve termini, and pancreatic islets
alpha 1 effects
vasoconstriction, intestinal relaxation, uterine contraction and pupillary dilation
alpha 2 effects
platelet aggregation, vasoconstriction, and inhibition of NE release and of insulin secretion
B 1 sites of action
heart
B 2 sites of action
lungs, gastrointestinal tract, liver, uterus, vascular smooth and skeletal muscle
B 1 effects
tachycardia
B 2 effects
brochodilation, smooth muscle relaxation, sphincter constriction
stage of reistance/apadtation
- all catecholamine responses are still exhibited
- cortisol reactions are also prominenet
- the immune responses during the stage of adaptation are adaptive
- aldosterone encourages salt and water retention to help raise blood pressure
- blood glucose and fatty acid levels are elevated
Coping mechanisms are ________
very unique to everyone
Stage of exhaustion
- coping is ineffective
- -stress response continues
- allostatic load
Allostatic overload
physiological consequences of chronic exposure to fluctuating or heightened neural or neuroendocrine response that results from repeated or chronic stress