stress and illness Flashcards
Define Stress
Stress is an alarm reaction that involves heightened mental and physical state as a response to a stressor.
Define homeostasis
The collective processes that maintain an internal equilibrium.
How do behaviors and emotions manifest themselves in the internal physical system?
In concert with the ANS and endocrine systems
Define Allostasis
Activity that is required for the individual to maintain stability by changing some aspect of themselves or their environment.
In short, adaptation
What are the two types of stresses sources?
Physiological and psychological
What are the three variations of the two main sources of stress?
Acute, episodic, and chronic
Which type of stress is the “bottom up” type of stress?
The physiological
Describe how signals from the periphery affect what we consciously feel.
Signals from the PNS progress to the spinal cord, to reach the brainstem. Once there, they move to the hypothalamus and limbic system, to evoke changes in homeostasis.
What types of stress are “top down” stresses?
Psychological
How does psychological stress exert its effects?
It affects the hypothalamic and brainstem mechanisms through the same regulatory mechanisms involved in external stresses.
What is the first phase in Seyle’s general adaptation syndrome?
Alarm stage: divided into two subphases:
Shock phase - body endures a stress and resistance to stressor drops temporarily
Antishock phase - body starts to respond and is in a state of alarm (Smpathetic nervous system kicks in, epi, cortisol)
What is the second phase in Seyle’s general adaptation syndrome?
Resistance (coping) stage -Increase in systemic glucocorticoid levels, leading to increases Glucose, fat, and protein in the blood.
If the stress is persistent, need an adaptation before the body’s resources are depleted.
What is the third phase in Seyle’s general adaptation syndrome?
Exhaustion stage - characterized by loss of normal body function, and long term damage.
What is the HPA axis?
The hypothalamus, pituitary, and adrenal glands axis. This is the order of secretion for adrenal secretion.
What is the first step in activation of the HPA axis?
The hypothalamus receives a signal from the higher parts of the brain (or lower) that something is stressful.
It produces norepinephrine, dopamine, and serotonin.
What is the third step in the HPA axis?
CRH produced by the hypotalamus activates the pituitary to secrete ACTH.
What is the fourth step in the HPA axis?
ATCH from the pituitary acts on the adrenal glands to stimulate cortisol production
How is anxiety (as opposed to an all out panic) represented physiologically in the brain?
The prefrontal cortex will communicate with the amygdala to assess the threat.
How is panic (as opposed to anxiety) represented physiologically in the brain?
The amygdala fully takes over–there is no communication with the prefrontal cortex as there is with anxiety.
What is the role of hippocampus in stress?
Since the hippocamus has a lot of cortisol receptors, it will try to shut off the amygdala if there is too much stress. —long term problems for chronic stress.
What is the long term effect of stress on the hippocampus?
Atrophy
What is allosteric load?
The cost of maintaining homeostasis.
Describe the short loop of inhibition
ACTH from the pituitary will inhibit the amygdala/CNS, and hypothalamus
Describe the long loop of inhibition
Cortisol will inhibit the hypothalamus/hippocampus, and anterior pituitary
What is the second step in the HPA axis activation?
Norepinephrine, dopamine, and serotonin cause the paraventricular nucleus in the hypothalamus to secrete CRH
What are some long term physical effects of chronic stress?
CV (sudden death, MI, HTN).
diarrhea, ulcers, IBS aggravation
How does HPA axis activation affect the immune system?
Lowers it:
lower cytokine production
lower inflammatory mediatos,
lower the tissues response to mediators
Depression in chronic stress is highly correlated with what?
Frequency of pain Inhibition of daily functioning Number of pain sites Duration of pain Severity
(FINDS)
