From
the blood circulating within it, the
kidneys filter urea which then travels from
the
ureter to the bladder to be expelled as urine.
While
solids are expelled by the digestive
system, liquid wastes are eliminated via the urinary system.
The urinary
system starts in the kidneys,
bean shaped organs that are roughly the size of a human fist.
Kidneys filter and regulate the blood in a number of different
ways, but for the purposes of the urinary system, the important
filtering is of urea - the nitrogen based waste product that
the kidneys remove from the bloodstream.
From there
it is sent along the tubular shaped ureter to the next part
of the urinary system, the bladder.
The bladder
is a hollow organ comprised of muscle tissue that swells and
deflates based on how much liquid it contains.
Since
the average bladder can hold roughly one liter of liquid (but
not comfortably), nerve endings in the bladder wall will signal
the brain when it's time to be emptied.
Urination,
which is fortunately a conscious process, commences when the
muscles of the bladder contract, forcing the liquid it contains
to exit the body via the urethra.
Maintaining a healthy urinary system
The urinary
system determines how much waste should be eliminated based
partly on how much water there is in the body.
Therefore,
keeping properly hydrated through the day not only serves
to keep the urinary system flushed of harmful salts and minerals,
but by extension keeps all bodily functions in good working
order.
Along
with plenty of water, watching the foods we eat is also important
in maintaining urinary system health.
A diet
high in fat especially may lead to the formation of kidney
stones, and being overweight can also lead to related
illnesses by putting extra pressure on the organs of the urinary
system.
Good hygiene
is also important to preventing urinary tract infections (UTI's)
especially in women, who are more prone to the condition due
to their particular anatomy, which situates the urethral opening
very close to the vagina and anus. A simple way for women
to combat infection, say doctors, is by wiping the genital
area back to front after urinating or defecating to avoid
introducing bacteria into the urethral opening.
More about the urinary system around the Web:
Your Urinary System and How It Works
- Extensive overview with detailed information on urinary
system functions, problems and disorders, plus surf the left
hand menu for an A-Z article library with more information
on kidney and bladder disease, urinary tract infections, treatment
options and health advice.
The
Urinary System - Comprehensive overview including
kidney and bladder function, urine production, plus related
illustrations and glossary, with more on urinary system disorders
with related diet and health tips.
Your
Urinary System - Excellent kid's guide to the kidneys
and bladder, with related resources including feature stories
on kidney anatomy, bed wetting.