TARSALGIA
TECHNETIUM
tarsalgia Pain in the rear part of the foot,
usually associated with
flat-feet.
tarsorrhaphy Surgery in which the upper
and lower eyelids are partially or com-
pletely sewn together. Tarsorrhaphy may
be used as part of the treatment of
corneal ulcer, or to protect the corneas
of people who cannot close their eyes or
those with
exophthalmos.
The eyelids
are later cut apart and allowed to open,
tarsus The 7 bones that make up the
back of the foot and the ankle,
tartar See
calculus
,
dental.
taste One of the 5 senses. Taste can dis-
tinguish only between sweet, salt, sour,
and bitter, but in combination with the
sense of
smeU,
many different flavours
can be distinguished. Tastes are detect-
ed by structures called
taste buds.
taste
bud One of
10,000 specialized
structures located mainly on the
tongue,
with some at the back of the throat and on
the palate. Each bud contains about 25
sensory receptor cells, with tiny taste hairs
that respond to food and drink. Taste buds
on different parts of the tongue sense the
4 basic
tastes:
bitter, sour, salty, and sweet.
taste, loss of Loss of the sense of
taste,
usually as a result of the loss of the
sense of
smell.
The most common cause
is inflammation of the nasal passages.
Other causes of loss of taste include
any condition that causes a dry mouth
(see
mouth
, dry); natural degeneration
of the
taste buds;
damage to the taste
buds from
stomatitis, mouth cancer,
or
radiotherapy
to the mouth; or damage
to nerves that carry taste sensations,
tattooing The introduction of permanent
colours under the skin surface, usually to
create a picture. Small tattoos can be
removed by cutting out the tattoo and
stitching the wound edges together. Lar-
ger tattoos can sometimes be removed
by
dermabrasion
or by
laser treatment.
taxanes A group of
anticancer drugs
used
to treat certain cancers, such as ovarian
cancer (see
ovary cancer of)
and
breast
cancer.
They work by preventing the
growth of cancer cells. Common taxane
drugs include
paclitaxel
and docetaxel.
Tay-Sachs disease A serious inherited
metabolic disorder (see
metabolism
,
in-
born errors of)
that causes premature
death. The cause is deficiency of the
enzyme hexosaminidase A, which results
in a buildup in the brain of a harmful
substance. Symptoms usually appear af-
ter age 6 months and include blindness,
paralysis, and seizures leading to death.
Diagnosis is made by enzyme analysis of
white blood cells. It is now largely pre-
vented by
genetic
counselling
of high-
risk groups.
TB An abbreviation
for
tuberculosis.
T-cell A class of
lymphocyte.
tears The watery,
salty secretion that
is produced by the
lacrimal glands, part
of the
lacrimal ap-
paratus
of the
eye.
Tears keep the
cor-
nea
and
conjunctiva
moist to maintain
transparency of the
cornea and prevent
ulcers; aid blinking;
and wash away for-
eign particles. Tear production increases
in response to eye irritation and emotion,
tears, artificial Preparations to supple-
ment tear production in disorders that
cause dry eye, such as
keratoconjunctivitis
sicca,
and to relieve irritation,
technetium A radioactive element used
in
radionuclide scanning.
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