BACTERIAL VAGINOSIS
BALANCE
Aerobic bacteria require oxygen to grow
and multiply; in the body, these are
most commonly found on the skin or in
the respiratory system. Anaerobic bac-
teria thrive where there is no oxygen,
deep within tissue or wounds. They
reproduce by simple division, which can
take place every 20 minutes. Some bacte-
ria also produce spores that can survive
high temperatures, dry conditions, and
lack of nourishment; and some produce
poisons (either endotoxins or exotox-
ins) that are harmful to human cells.
The body's
immune system
attacks
invading bacteria, but in some cases
treatment with
antibiotic drugs
is neces-
sary and will speed recovery. Superficial
inflammation and infected wounds may
be treated with
antiseptics.
Immunity to
invading bacterial diseases, such as
some types of
meningitis
, can be ac-
quired by active
immunization
. (See also
infectious disease
.)
BACTERIA
Flagellum
Cell wall
Pilus
Nucleoid containing
genetic material
A ROD-SHAPED BACTERIUM
bacterial vaginosis
An infection of the
vagina
that causes a greyish-white dis-
charge and itching. The disorder is due
to excessive growth of bacteria that
normally live in the vagina. It is more
common in sexually active women and
is treated with
antibiotic drugs.
bactericidal
A term used to describe
any substance that kills bacteria. (See
also
antibacterial drugs; antibiotic drugs.)
bacteriology
The study of
bacteria,
par-
ticularly of the types that cause disease.
Bacteriology includes techniques used
to isolate and identify bacteria from
specimens such as a throat swab or
urine. Bacteria are identified by their ap-
pearance under a microscope, including
their response to stains (see
staining
)
and the use of
culture
. Testing for sensi-
tivity to antibiotics may be performed.
bacteriostatic
A term used to describe
a substance that stops the growth or
multiplication of
bacteria
but does not
kill them. (See also
antibacterial drugs
;
antibiotic drugs.)
bacteriuria
The presence of
bacteria
in
the urine that is abnormal.
bad breath
See
halitosis.
bagassosis
A rare disease affecting the
lungs of workers who handle mouldy
bagasse (the fibrous residue of sugar-
cane after juice extraction). Bagassosis
is one cause of allergic
alveolitis
. Symp-
toms develop 4-5 hours after inhaling
dust and include shortness of breath,
wheezing, fever, headache, and cough.
Repeated dust exposure may lead to
permanent lung damage.
Baker's cyst
A fluid-filled lump behind
the knee. A Baker's cyst is caused by
increased pressure in the knee joint due
to a buildup of fluid in a disorder such
as
rheumatoid arthritis.
Most Baker's
cysts are painless, and some disappear
spontaneously. Occasionally, a cyst may
rupture, producing pain and swelling in
the calf that can mimic a deep vein
thrombosis (see
thrombosis
,
deep vein
).
Diagnosis of a Baker's cyst is confirmed
by
ultrasound scanning
. Treatment is
rarely needed.
balance
The ability to remain upright and
move without falling over. Information on
body position is relayed to the brain by
many parts of the body: the eyes; pro-
prioceptors (sense organs) in the skin,
muscle, and joints; and the labyrinth of
the inner ear. The
cerebellum
(part of the
brain) integrates the information and
sends instructions to enable various
parts of the body to perform adjust-
ments needed to maintain balance.
Disorders affecting the ear, brain, or
spinal cord commonly affect balance.
Ear disorders include
labyrinthitis
and
Meniere's disease.
Less commonly,
otitis
m edia
may affect balance.
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