From Wikipedia,
the free encyclopedia.
Chronobiology is a field
of
science that examines periodic
(cyclic) phenomena in living
organisms. These cycles are
important for many essential
biological processes that occur
(a) in animals (eating, sleeping,
mating, hibernating, migration,
cellular regeneration, etc), and
(b) in plants (leaf movements,
photsynthetic reactions, etc.).
The most important rhythm in
chronobiology is the
circadian rhythm, which refers
to an approximate 24-hour daily
biological cycle; however, many
other important cycles are also
studied, including:
-
Infradian rhythms, which are
long-term cycles, such as the
annual migration or reproduction
cycles found in certain animals
or the human
menstrual cycle.
-
Ultradian rhythms, which are
short cycles, such as the
90-minute
REM cycle in sleep or the 3
hour cycle of
growth hormone production.
They have periods of less than
24 hours.
-
Tidal rhythms, commonly
observed in marine life, which
follow the (roughly) 12-hour
transition from high to low tide
and back.
Un-related to chronobiology is
the unsubstantiated theory of
biorhythms, which are said to
be a set of cyclic variations in
human behaviour. The theory's
basis lies in physiological and
emotional cycles. Some people
consider it
pseudoscience and others
protoscience.
Light therapy and
melatonin administration have
been explored by Dr. Alfred J.
Lewy (OHSU)
and other researchers as a means
to reset abnormal circadian
rhythms.
Patents
-
U.S. Patent 6,268,309 - Use
of a composition and a method
for the promotion of plant
production and/or for the
elimination of the unfavorable
influences in plant cultivation
