ACUITY, VISUAL
ADENOCARCINOMA
of actinomycosis affects the pelvis in
women, causing lower abdominal pain
and bleeding between periods. This
form was associated with a type of
IUD
,
no longer in use, that did not contain
copper. Rarely, forms of the disorder
affect the appendix or lung. Actinomy-
cosis is treated with
antibiotics.
acuity, visual
See
visual acuity.
acupressure
A derivative of
acupunc-
ture
in
which
pressure
is
applied
instead of needles.
acupuncture
A branch of
Chinese m ed-
icine
in which needles are inserted into
a patient's skin as therapy for various
disorders or to induce anaesthesia.
Traditional Chinese medicine main-
tains that the chi (life-force) flows
through the body along channels called
meridians. A blockage in one or more of
these meridians is thought to cause ill
health. Acupuncturists aim to restore
health by inserting needles at appropri-
ate sites along the affected meridians.
The needles are stimulated by rotation
or by an electric current. Acupuncture
has been used successfully as an anaes-
thetic for surgical procedures and to
provide pain relief after operations and
for chronic conditions.
acute
A term often used to describe a
disorder or symptom that develops sud-
denly. Acute conditions may or may not
be severe, and they are usually of short
duration. (See also
chronic
.)
Adam's apple
A projection at the front
of the neck, just beneath the skin, that
is formed by a prominence on the thy-
roid cartilage, which is part of the
larynx
(voice box). The Adam's apple enlarges
in males at puberty.
ADD
The abbreviation for attention defi-
cit disorder, more commonly known as
attention deficit hyperactivity disorder.
addiction
Dependence on, and craving
for, a particular drug, for example alco-
hol, diazepam (a tranquillizer), or heroin.
Reducing or stopping intake of the drug
may lead to characteristic physiological
or psychological symptoms (see
with-
drawal syndrom e
), such as tremor or
anxiety. (See also
alcohol dependence
;
drug dependence
.)
Addison's disease
A rare chronic dis-
order in which there is a deficiency of
the corticosteroid hormones
hydrocorti-
sone
and
aldosterone
, normally produced
by the adrenal cortex (the outer part of
the
adrenal glands
). Excessive amounts
of
ACTH
are secreted by the pituitary
gland in an attempt to increase output
of the corticosteroid hormones. Secre-
tion and activity of another hormone,
melanocyte stimulating hormone (MSH),
is also increased.
Addison's disease can be caused by
any disease that destroys the adrenal
cortices. The most common cause is an
autoimmune
disorder
in
which
the
immune system produces antibodies
that attack the adrenal glands.
Symptoms generally develop gradu-
ally over months or years, and include
tiredness, weakness, abdominal pain,
and weight loss. Excess MSH may cause
darkening of the skin in the creases of
the palms, pressure areas of the body,
and the mouth. Acute episodes, called
Addisonian crises, brought on by infec-
tion, injury, or other stresses, can also
occur. The symptoms of these include
extreme muscle weakness, dehydration,
hypotension
(low blood pressure), con-
fusion, and coma.
Hypoglycaemia
(low
blood glucose) also occurs.
Life-long
corticosteroid drug
treatment
is needed. Treatment of Addisonian
crises involves rapid infusion of saline
and glucose, and supplementary doses
of corticosteroid hormones.
adduction
Movement of a limb towards
the central line of the body, or of a digit
towards the axis of a limb. Muscles that
carry out this movement are often called
adductors. (See also
abduction.)
adenitis
Inflammation of
lymph nodes.
Cervical adenitis (swelling and tender-
ness of the lymph nodes in the neck)
occurs in certain bacterial infections,
especially
tonsillitis
, and glandular fever
(see
infectious mononucleosis). M esen-
teric lymphadenitis
is inflammation of
the lymph nodes inside the abdomen
and is usually caused by viral infection.
Treatment of adenitis may include
anal-
gesic drugs
, and
antibiotic drugs
if there
is a bacterial infection.
adenocarcinoma
The technical name
for a
cancer
of a gland or glandular tis-
sue, or for a cancer in which the cells
A
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