scarred area of the abdominal wall
because the muscle has been weakened
by a previous surgical incision.
incisorOne of the 8 front teeth (4 in the
upper jaw and 4 in the lower) used for
cutting through solid food (see teeth).
incontinence, faecal Inability to retain
faecesin the rectumuntil a movement
appropriate to expel them. A common
cause is faecal impaction, which often
results from long-standing constipation.
The rectum becomes overfull causing
faecal fluid and small pieces of faeces to
be passed involuntarily aroundthe im-
pacted mass of faeces. Temporary loss
of continence may also occur in severe
diarrhoea. Other causes include injury
to the anal muscles (as may occur during
childbirth), paraplegia, and dementia.
If the underlying cause of faecal im-
paction is constipation, recurrence may
be prevented by a high-fibre diet. Sup-
positories containing glycerolor laxative
drugsmay be recommended. Faecal in-
continence in people with dementia or
a nerve disorder may be avoided by reg-
ular use of enemasor suppositoriesto
empty the rectum.
incontinence, urinary Involuntary pass-
ing of urine, often due to injury or
disease of the urinary tract. There are
several types. Stress incontinence refers
to the involuntary escape of urine when
a person coughs, picks up a heavy pack-
age, or moves excessively. It is common
in women, particularly after childbirth,
when the urethral sphincter muscles are
stretched. In urge incontinence, also
known as irritable bladder, an urgent
desire to pass urine is accompanied by
inability to control the bladder as it con-
tracts. Once urination starts, it cannot
be stopped. Total incontinence is a com-
plete lack of bladder control due to an
absence of sphincter activity, which may
be associated with spinal cord damage.
Overflow incontinence occurs in long-
term urinary retention, often because of
an obstruction such as an enlarged
prostate gland. The bladder is always full,
leading to constant dribbling of urine.
Incontinence may also be due to urin-
ary tract disorders (including infections,
bladder stones, or tumours) or prolapse
of the uterus or vagina. Incontinence dueto lack of control by the brain commonly
occurs in the young (see enuresis) or eld-
erly and those with learning difficulties.
If weak pelvic muscles are causing
stress incontinence, pelvic floor exercises
may help. Sometimes, surgery may be
needed to tightenthe pelvic muscles or
correct a prolapse. Anticholinergic drugs
may be used to relax the bladder mus-
cle if irritable bladder is the cause.
If normal bladder function cannot be
restored, incontinence pants can be worn;
men can wear a penile sheath leading
into a tube connected to a urine bag.
Some people can avoid incontinence by
self-catheterization (seecatheterization,
urinary). Permanent catheterization is
necessary in some cases.
incoordinationLoss of the ability to
produce smooth, muscular movements,
leading to clumsiness and unsteady bal-
ance. Incoordination can also mean the
failure of a group of organs to work
together successfully. (See also ataxia.)
incubation period The time during
which an infectious diseasedevelops,
from the point when the infecting organ-
ism enters the body until symptoms
appear. Different infections have charac-
teristic incubation periods; for example,
14–21 days for chickenpox and 7–14 days
for measles. The incubation period for
cholera may be as short as several hours.
incubatorA transparent plastic cot in
which oxygen, temperature, and humid-
ity are controlled in order to provide
premature or sick infants with ideal
conditions for survival. Incubators have
portholes to allow handling of the baby
and smaller ones through which mon-
itoring cables and intravenous and
respiratory tubing can pass.
incusOne of the 3 tiny, linked bones
(ossicles) in the middle ear. The incus
(the Latin name for anvil) is so-called
because of its shape.
Indian medicineTraditional Indian, or
Ayurvedic, medicine was originally based
largely on herbal treatment, although
simple surgical techniques were also
used. Indian medicine later developed
into a scientifically based system with a
wide range of surgical techniques (such
as operations for cataracts and kidney
stones) along with the herbal tradition.INCISOR INDIAN MEDICINEI