Hi, thanks for your questions. While I'm prohibited from providing you
with the direct responses to your questions, I am able to provide you
with access to the information so that you may more easily acquire the
information you seek. I will start by providing you with some
background info on the subjects at hand and then proceed to provide
links and excerpts that relate directly to your specific questions.
Finally, I will provide some additional links and information for
further study.
BACKGROUND INFORMATION
Homeostasis: emphasis is on steady state and optimal set points
Allostasis: emphsis is on optimal operating ranges of physiological systems
Allostatic Load: stability through change represents the cumulative,
multi-system view of physiological toll that may be exacted on the
body through attempts at adaptation.
An organism must vary all parameters of its internal milieu and match
them appropriately to environmental demands.
http://mcb.berkeley.edu/courses/mcb135k/allostasis.htm
Homeostasis:
"HOMEOSTASIS describes the state of dynamic balance maintained by
multiple interacting systems that constitute the self_regulatory
processes of physiological compensation for environmental
fluctuations"
http://notes.utk.edu/bio/greenberg.nsf/0/a6a7f733a0452ef085256d34008073a9?OpenDocument
"A person threatened by the environment (or informed of an approaching
pleasure or danger) prepares for action. The body mobilizes reserves
of energy and produces certain hormones such as adrenalin, which
prepare it for conflict or flight. This mobilisation can be seen in
familiar physiological reactions. In the presence of emotion, danger,
or physical effort the heart beats faster and respiration quickens.
The face turns red or pales and the body perspires. The individual may
experience shortness of breath, cold sweats, shivering, trembling
legs. These physiological manifestations reflect the efforts of the
body to maintain its internal equilibrium. Action can be voluntary--to
drink when one is thirsty, to eat when hungry, to put on clothing when
cold, to open a window when one is too warm--or
involuntary--shivering, sweating.
The internal equilibrium of the body, the ultimate gauge of its proper
functioning, involves the maintenance of a constant rate of
concentration in the blood of certain molecules and ions that are
essential to life and the maintenance at specified levels of other
physical parameters such as temperature. This is accomplished in spite
of modifications of the environment."
http://pespmc1.vub.ac.be/HOMEOSTA.html
Notes on allostasis:
http://notes.utk.edu/bio/greenberg.nsf/d037c09bfc9baf5185256a6b0017e224/42f654016f6f531285256dd6004fb2ef?OpenDocument
SPECIFIC QUESTIONS
1.Distinguish between homeostasis and allostasis and how they are related:
Distinction and relation of between homeostasis and allostasis:
"Homeostatic responses are triggered when an excess or deficiency in a
specific variable has been detected. The threshold for detection may
be variable depending on various circumstances such as past experience
or other, competing responses. It represents part of a complex
"set-point." When the set-point is re-set to a new and stable value,
some authors consider the new stability 'heterostasis' or
'allostasis'"
http://notes.utk.edu/bio/greenberg.nsf/0/a6a7f733a0452ef085256d34008073a9?OpenDocument
2.Distinguish the memory effects of acute stress from those of chronic stress:
"Scores of scientists continue to explore one of our most basic mental
states-stress-and its effect on the mind and body. The consensus among
brain researchers and psychologists is that a little stress can be
helpful in certain situations, but that too much can do harm to memory
and other basic mental functions. These findings reiterate the
importance of managing stress throughout life, surfing the healthy
wave of mild to moderate mental stimulation it provides but avoiding
the destructive effects of chronic anxiety."
http://www.memorylossonline.com/stress.htm
Alosstatic role in chronic stress and memory loss:
http://www.dolfzine.com/page564.htm
3.From the WEB site of a very famous private American University:
?How to stay stressed.?please help to summary examples about how to
stay stressed, and explain why each actually contributes to stress:
Reasons why people seek to remain stressed, eg. STRESS HELPS YOU SEEM
IMPORTANT,etc.
http://www-psych.stanford.edu/~pinto/stress.html
4.How do those who practice hormesis explain this as an adaptive
response to stress? What does the NIEHS (National Institute for
Environmental Health Sciences) consider the final word on
?hormesis??please give specific example:
Hormesis response to ox-stress, from NIH (message board thread)
http://www.vanderbilt.edu/radsafe/0112/msg00482.html
Stress for Success
Too much stress is bad, but the right amount can prolong life and
bring other benefits by Mitch Leslie In: Science Magazine OnLine
http://www.myalgia.com/Archives/stress_for_success.htm
Notes on stress/ relation between homesis
http://mcb.berkeley.edu/courses/mcb135k/Stress&Hormesis(for%20web)
National Institute for Environmental Health Sciences
http://www.niehs.nih.gov/
5.How might stress and eating disorders be connected at the metabolic level?
Loyola University Health System
http://www.luhs.org/health/topics/mentalhealth/edbinge.htm
WHAT CAUSES EATING DISORDERS?
http://www.ucdmc.ucdavis.edu/ucdhs/health/a-z/49EatingDisorders/doc49causes.html
ADDITIONAL LINKS
Stress, adaptation, and disease. Allostasis and allostatic load.
Ann N Y Acad Sci. 1998 May 1;840:33-44.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?holding=npg&cmd=Retrieve&db=PubMed&list_uids=9629234&dopt=Abstract
"Adaptation in the face of potentially stressful challenges involves
activation of neural, neuroendocrine and neuroendocrine-immune
mechanisms. This has been called "allostasis" or "stability through
change" by Sterling and Eyer (Fisher S., Reason J. (eds): Handbook of
Life Stress, Cognition and Health. J. Wiley Ltd. 1988, p. 631), and
allostasis is an essential component of maintaining homeostasis."
allostasis and stress:
The neurobiology of stress: from serendipity to clinical relevance
Brain Res 2000 Dec 15; 886(1-2):172-189
http://www.biopsychiatry.com/stress.html
"The hormones and other physiological agents that mediate the effects
of stress on the body have protective and adaptive effects in the
short run and yet can accelerate pathophysiology when they are
over-produced or mismanaged. Here we consider the protective and
damaging effects of these mediators as they relate to the immune
system and brain. 'Stress' is a principle focus, but this term is
rather imprecise. Therefore, the article begins by noting two new
terms, allostasis and allostatic load that are intended to supplement
and clarify the meanings of 'stress' and 'homeostasis'. For the immune
system, acute stress enhances immune function whereas chronic stress
suppresses it."
Allostatic load can lead to disease
Ann N Y Acad Sci. 1998 May 1;840:33-44.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?holding=npg&cmd=Retrieve&db=PubMed&list_uids=9629234&dopt=Abstract
"However, there are a number of circumstances in which allostatic
systems may either be overstimulated or not perform normally, and this
condition has been termed "allostatic load" or the price of adaptation
(McEwen and Stellar, Arch. Int. Med. 1993; 153: 2093.). Allostatic
load can lead to disease over long periods. Types of allostatic load
include (1) frequent activation of allostatic systems; (2) failure to
shut off allostatic activity after stress; (3) inadequate response of
allostatic systems leading to elevated activity of other, normally
counter-regulated allostatic systems after stress. Examples will be
given for each type of allostatic load from research pertaining to
autonomic, CNS, neuroendocrine, and immune system activity. The
relationship of allostatic load to genetic and developmental
predispositions to disease is also considered."
Allostasis and allostatic load: implications for neuropsychopharmacology
Neuropsychopharmacology. 2000 Feb;22(2):108-24
"The concepts of allostasis and allostatic load center around the
brain as interpreter and responder to environmental challenges and as
a target of those challenges. In anxiety disorders, depressive
illness, hostile and aggressive states, substance abuse, and
post-traumatic stress disorder (PTSD), allostatic load takes the form
of chemical imbalances as well as perturbations in the diurnal rhythm,
and, in some cases, atrophy of brain structures. In addition, growing
evidence indicates that depressive illness and hostility are both
associated with cardiovascular disease (CVD) and other systemic
disorders. A major risk factor for these conditions is early childhood
experiences of abuse and neglect that increase allostatic load later
in life and lead individuals into social isolation, hostility,
depression, and conditions like extreme obesity and CVD. "
Allostasis, Homeostasis and the Costs of Physiological Adaptation
by Jay Schulkin (Editor)
http://www.amazon.com/exec/obidos/ASIN/0521811414/p11-20/ref%3Dnosim/002-1926395-0244827
GOOGLE SEARCH TERMS USED
allostatis
://www.google.com/search?q=allostasis&hl=en&lr=&ie=UTF-8&oe=UTF-8&start=10&sa=N
allostasis, homeostasis
://www.google.com/search?q=allostasis%2C+homeostasis&btnG=Search&hl=en&lr=&ie=UTF-8&oe=UTF-8
allostasis, homeostasis, memory, stress
://www.google.com/search?q=allostasis%2C+homeostasis%2C+memory%2C+stress&hl=en&lr=&ie=UTF-8&oe=UTF-8
?How to stay stressed? university
://www.google.com/search?hl=en&lr=&ie=UTF-8&oe=UTF-8&q=%E2%80%9CHow+to+stay+stressed%E2%80%9D+university
hormesis, stress
://www.google.com/search?hl=en&lr=&ie=UTF-8&oe=UTF-8&q=hormesis%2C+stress
National Institute for Environmental Health Sciences
://www.google.com/search?q=National+Institute+for+Environmental+Health+Sciences&btnG=Search&hl=en&lr=&ie=UTF-8&oe=UTF-8
stress, eating disorder
://www.google.com/search?q=stress,+eating+disorder&hl=en&lr=&ie=UTF-8&oe=UTF-8&start=30&sa=N
I HOPE THIS IS USEFUL. THANKS AGAIN.
CHEERS,
ANTHONY (ADILOREN-GA) |
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