RIBAVIRIN
RNA
RIB
The next 2 or 3 pairs of "false ribs" con-
nect indirectly to the sternum by means
of cartilage attached to the cartilage of
the ribs above. Between and attached
to the ribs are thin sheets of muscle
(intercostal
muscles) that act during
breathing.
The spaces between the ribs
also contain nerves and blood vessels,
ribavirin An
antiviral drug,
also called
tribavirin, used to treat children with
viral
bronchiolitis
caused by respiratory
syncytial virus. Adverse effects are rare,
rib, fracture of
Fracture
of a rib may
be caused by a fall or blow, or by stress
on the ribcage, such as that produced
by prolonged coughing. The fracture of
a rib causes severe pain, which may be
relieved by
analgesic drugs
or by an
injection of a local
anaesthetic.
riboflavin The chemical name of vitamin
B2 (see
vitamin B complex).
rickets A disease caused by nutritional
deficiency that causes
bone
deformities
in childhood. Bones become deformed
because inadequate amounts of
calcium
and
phosphate
are incorporated into
them as they grow. The most common
cause is
vitamin D
deficiency. It also
occasionally develops as a complication
of
malabsorption
and may also occur in
rare forms of kidney and liver disease.
Rickets due to dietary deficiency is
treated with supplements. The deformi-
ties usually disappear as the child grows.
Rickets occurring as a complication of a
disorder is treated according to the cause.
rickettsia A type of small
bacteria
that
can multiply only by invading other living
cells. They are mainly parasites of arthro-
pods such as ticks, lice, fleas, and mites.
Human diseases caused by
rickettsiae include
Q fever
,
Rocky Mountain spotted
fever,
and
typhus.
rifampicin An
antibacter-
ial drug
used mainly to
treat
tuberculosis.
It is also
used to treat
leprosy
and
legionnaires' disease.
The
drug is usually prescribed
with other antibacterials
because some strains of
bacteria develop resistance
if it is used alone.
Side effects include harm-
less, orange-red discoloration of the urine,
saliva, and other body secretions, muscle
pain, nausea, vomiting, diarrhoea, jaun-
dice, flu-like symptoms, rash, and itching.
The drug interferes with the action of
oral contraceptives.
rigidity Increased tone in one or more
muscles,
causing them to feel tight; the
affected part of the body becomes stiff
and inflexible. Causes include muscle
injury,
arthritis
in a nearby joint, a neu-
rological disorder, or
stroke.
Rigidity of
the abdominal muscles is a sign of
peri-
tonitis.
(See also
spasticity.)
rigor A violent attack of shivering, often
associated with a fever. Rigor may also
refer to stiffness or rigidity of body tis-
sues, as in
rigor mortis.
rigor m ortis The stiffening of muscles
that starts 3-4 hours after death. It is usu-
ally complete after about 12 hours; the
stiffness then disappears over the next
48-60 hours. Physical exertion before
death makes rigor mortis begin sooner.
The sooner rigor mortis begins, the
quicker it passes. These facts are used
to help assess the time of death,
ringing in the ears See
tinnitus.
ringworm A popular name for certain
fungal skin infections. Ringworm causes
ring-shaped, reddened, scaly, or blistery
patches on the skin. (See also
tinea.)
ritodrine A drug used to prevent or delay
premature labour (see
prematurity
). Side
effects may include tremor, chest pain,
palpitations
, nausea, vomiting, and flushing.
river blindness See
onchocerciasis
.
RNA The abbreviation for ribonucleic
acid. RNA and
DNA
carry inherited
genetic instructions. In animal and plant
R
493
previous page 491 BMA Illustrated Medical Dictionary read online next page 493 BMA Illustrated Medical Dictionary read online Home Toggle text on/off