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EMR >> EMR Specialty
Immunology
Electronic Medical Records
Immunology
Immunology
is a broad branch of biomedical science that covers the
study of all aspects of the immune system in all organisms.
It deals with, among other things, the physiological
functioning of the immune system in states of both health
and disease; malfunctions of the immune system in
immunological disorders (autoimmune diseases,
hypersensitivities, immune deficiency, allograft rejection);
the physical, chemical and physiological characteristics of
the components of the immune system in vitro, in situ, and
in vivo. Immunology has various applications in several
disciplines of science, and as such is further divided.
Even before the concept of immunity (from immunis, Latin for
"exempt") was developed, numerous early physicians
characterised organs that would later prove to be part of
the immune system. The key organs of the immune system are
thymus, spleen, bone marrow, lymph vessels, lymph nodes and
secondary lymphatic tissues such as tonsils, adenoids, and
skin. Two major organs, the thymus and spleen, are examined
histologically only post-mortem during autopsy. However some
lymph nodes and secondary lymphatic tissues can be
surgically excised for examination while patients are still
alive.
Many components of the immune system are actually cellular
in nature and not associated with any specific organ but
rather are embedded or circulating in various tissues
located throughout the body.
Classical immunology ties in with the
fields of epidemiology and medicine. It studies the
relationship between the body systems, pathogens, and
immunity. The earliest written mention of immunity can be
traced back to the plague of Athens in 430 BC. Thucydides
noted that people who had recovered from a previous bout of
the disease could nurse the sick without contracting the
illness a second time. Many other ancient societies have
references to this phenomenon, but it was not until the 19th
and 20th centuries before the concept developed into
scientific theory.
The study of the molecular and cellular components that
comprise the immune system, including their function and
interaction, is the central science of immunology. The
immune system has been divided into a more primitive innate
immune system, and acquired or adaptive immune system of
vertebrates, the latter of which is further divided into
humoral and cellular components.
Study of the immune system in extant and extinct
species is capable of giving us a key understanding of the
evolution of species and the immune system.
A development of complexity of the immune system can be seen
from simple phagocytotic protection of single celled
organisms, to circulating antimicrobial peptides in insects
to lymphoid organs in vertebrates. Of course, like much of
evolutionary observation, these physical properties are
often seen from the anthropocentric aspect. It should be
recognised, that every organism living today has an immune
system absolutely capable of protecting it from most forms
of harm; those organisms that did not adapt their immune
systems to external threats are no longer around to be
observed.
Insects and other arthropods, while not possessing true
adaptive immunity, show highly evolved systems of innate
immunity, and are additionally protected from external
injury (and exposure to pathogens) by their chitinous
shells.
Source: Wikipedia contributors (2005). Immunology. Wikipedia,
The Free Encyclopedia. Retrieved 12:17, December 26, 2005
from http://en.wikipedia.org/w/index.php?title=Immunology&oldid=31939456.
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