of the small
intestine. Diagnosis of Meckel's divertic-
ulum may be made by using technetium
occur, they are treated by surgical re-
moval of the diverticulum.
The thick, sticky, greenish-
black faeces passed by infants in the
first day or two after birth. It consists of
, mucus, and shed intestinal cells.
Occasionally, the fetus passes meco-
nium into the
uterus. This is more common in babies
labour or who are over 40 weeks' gesta-
tion. Meconium in the amniotic fluid
may be inhaled when the baby starts to
breathe, sometimes blocking the air-
ways and damaging the lungs.
In some babies with
meconium is so thick and sticky that
it blocks the intestine (see
A medical term that means “sit-
uated towards the midline of the body”.
Less commonly, the term refers to the
middle layer of a body structure.
One of the main nerves
of the arm. It is a branch of the
and runs down the arm from the
shoulder into the hand. The median
nerve controls the muscles that carry
out bending movements of the wrist,
fingers, and thumb, and that rotate the
forearm palm-inwards. The nerve also
conveys sensations from the thumb and
first 3 fingers, and from the region of
the palm at their base.
Damage to the nerve may result from
injury to the shoulder, a
just above the wrist, or pressure on the
nerve where it passes through the wrist
carpal tunnel syndrome
damage include numbness and weak-
ness in areas controlled by the nerve.
Investigation of the
by means of an
inserted through an incision in the neck.
Mediastinoscopy is used mainly to
sample is removed by tiny blades on
The membranous parti-
tion between the lungs and the other
structures within the chest cavity. These
structures include the
ated blood vessels,
vessels, and nerves.
Any substance prescribed to
treat disease. (See also
The study of human diseases,
their causes, frequency, treatment, and
prevention. The term is also applied to
a substance prescribed to treat illness.
Relating to aspects of med-
icine and law that overlap. Among the
matters on which medicolegal experts
advise are the laws concerning damages
for injuries due to medical negligence
or malpractice, evidence concerning the
extent of injury in a civil action, the use
of paternity tests, the mental compet-
ence of people who have drawn up wills,
and restrictions on the mentally ill.
Medicolegal issues also include an
individual's right to die (see
euthanasia; living will);
the necessity for
to any surgical pro-
cedure; the legal aspects of
insemination, in vitro fertilization, steril-
and a patient's
concerning his or
her illness. (For the medical aspects of
criminal law, see
Concentrating on an object,
a word, or an idea with the aim of induc-
ing an altered state of consciousness.
At its deepest level, meditation can
resemble a trance. More commonly, it is
a calming therapy and can be a way of
reducing stress levels and treating stress-
related disorders. A common form of
meditation practised in the west is tran-
scendental meditation (TM).
used to treat
certain types of
ine cancer (see
uterus, cancer of
). It is
sometimes used to treat menstrual dis-
orders such as
of menstruation). Medroxyprogesterone
can also be used as a contraceptive,
administered by injection at 3-monthly
). Possible adverse effects
include weight gain, swollen ankles, and
The innermost part of an organ
or other body structure; for example,