Flashcards in Module 12.3 Deck (18)
What was Hans Selye's definition of stress?
A nonspecific response of the body to any demand made upon it
What is General Adaptation Syndrome?
A generalized response to any kind of stress
What occurs in each stage of general adaptation syndrome?
Alarm-increased activity of the sympathetic nervous system, readying the body for brief emergency activity
Resistance-sympathetic response declines, but adrenal xortex secretes cortisol and other hormones that enable the body to maintain prolonged alertness, fight infections, and heal wounds
Exhaustion-the individual is tired, inactive, and vulnerable because the nervous system and immune systems no longer have the energy to sustain their heightened responses
Describe the steps in the control of cortisol secretion from the adrenal cortex.
Activation of the hypothalamus induces the anterior pituitary gland to secrete ACTH, which in turn stimulates the human adrenal cortex to secrete cortisol.
What is the function of cortisol?
It mobilizes the body's enegies to fight a difficult situation, converts proteins to glucose, enhance metabolic activty, and elevates blood levels of sugar and other nutrients.
What are antigens?
Proteins on the surface of a microorganism in response to which the immune system generates antibodies
What are the roles of B cells?
attack cells with unfamiliar antigens
What are the roles of T cells?
they attack intruders and some help other T cells or B cells to multiply
What are the roles of natural killer cells?
attack tumor cells and cels that are infected with viruses
What are cytokines?
Small proteins that combat infections and also communicate with the brain to elicit appropriate behaviors
What evidence suggests cytokines their influence on depression?
Many of the symptoms of depression are the same symptoms of illness and are probably related to the increased cytokines in depressed people
What is the effect of short-term stress on the immune system?
it increases immune system activity
Describe the evidence suggesting that long-term stress impairs the functioning of the immune system.
People who reported stress lasting longer than a month were injected with a moderate dose of common cold virus and the longer the stress lasted, the greater the risk of illness.
What are cortisol's major effects on blood sugar and metabolism? How does this affect the immune system?
It enhances metabolic activity and elevates blood levels of sugar and other nutrients.This can suppress the immune system.
Describe how cortisol levels affect the hippocampus.
Cortisol enhances metabolic activity throughout the body and when metabolic activity is high in the hippocampus, its cells become more vulnerable to damage from toxins or overstimulation.
What are the symptoms of PTSD?
Frequent flashbacks and nightmares about the traumatic event, avoudance of reminders of it, and exaggerated arousal in response to noises and other stimuli
Describe how cortisol levels might make some people more vulnerable to PTSD.
PTSD victims have lower levels of cortisol and may be ill-equipped to combat stress and therefor more vulnerable to the damaging effects of stress and more prone than other people to PTSD