BILIARY COLIC
BIOCHEMISTRY
The symptoms and signs of secondary
biliary cirrhosis include abdominal pain
and tenderness, liver enlargement, fev-
ers and chills, and sometimes blood
abnormalities. Treatment is the same as
for bile duct obstruction.
biliary colic
A severe pain in the upper
right quadrant of the abdomen that is
usually caused by the gallbladder's
attempts to expel
gallstones
or by the
movement of a stone in the bile ducts.
The pain may be felt in the right shoul-
der (see
referred pain)
or may penetrate
to the centre of the back. Episodes of
biliary colic often last for several hours
and may recur, particularly after meals.
Injections of an
analgesic drug
and an
antispasmodic drug
may be given to
relieve the colic. Tests such as
cholecys-
tography
or
ultrasound scanning
can
confirm the presence of gallstones, in
which case
cholecystectomy
(surgical
removal of the gallbladder) is possible.
biliary system
The organs and ducts by
which
bile
is formed, concentrated, and
carried from the
liver
to the duodenum
(the first part of the small intestine).
Bile is secreted by the liver cells and
collected by a network of
bile ducts
that
carry the bile out of the liver by way of
the hepatic duct. A channel called the
cystic duct branches off the hepatic
duct and leads to the gallbladder where
bile is concentrated and stored. Beyond
this junction, the hepatic duct becomes
the common bile duct and opens into the
duodenum at a controlled orifice called
the ampulla of Vater. The presence of fat
in the duodenum after a meal causes
secretion of a hormone, which opens
the ampulla of Vater and makes the
gallbladder contract, squeezing stored
bile into the duodenum.
The main disorders affecting the bil-
iary system are
gallstones
, congenital
biliary atresia
and
bile duct obstruction.
(See also
gallbladder
,
disorders of.
)
biliousness
A condition in which bile is
brought up to the mouth from the sto-
mach. It is also used as a nonmedical
term for nausea and vomiting.
bilirubin
The main pigment found in
bile
. It is produced by the breakdown of
haem oglobin
, the pigment in red blood
cells. Excessively high levels of bilirubin
cause the yellow pigmentation associ-
ated with
jaundice
.
Billings' method
Also called the mucus
inspection method, a technique in which
a woman notes changes in the character-
istics of mucus produced by the cervix
in order to predict ovulation for the pur-
poses of
contraception
or
family planning
.
Billroth's operation
A type of partial
gastrectomy
in which the lower part of
the stomach is removed. Once used as
a surgical treatment for
peptic ulcers
, it
has now largely been replaced by treat-
ment with
antibiotic drugs
.
Binet test
The first
intelligence test
that
attempted to measure higher mental
functions, devised in 1905.
binge-purge syndrome
An alterna-
tive term for
bulimia.
bio-
A prefix describing a relationship to
life, as in biology, the science of life.
bioavailability
The proportion of a drug
that reaches the target organs and tis-
sues, usually expressed as a percentage
of the dose administered. Intravenous
administration results in 100 per cent
bioavailability because the drug is in-
jected directly into the bloodstream.
Drugs taken orally have a much lower
bioavailability. Preparations that have
equal bioavailabilities are described as
bioequivalent. (See also drug.)
biochemistry
A science that studies
the chemistry of living organisms. It in-
cludes the chemical processes involved
in the maintenance and reproduction of
body cells and the chemical reactions
carried out inside cells that make up
the
metabolism
of the body. Overall reg-
ulation of these chemical processes is a
function of
horm ones
, whereas regula-
tion of individual reactions is carried
out by
enzymes
. A constant interchange
occurs between cell fluids and blood
and urine. Biochemists can therefore
learn about the chemical changes going
on inside cells from measurements of
the various minerals, gases, enzymes,
hormones, and proteins in blood, urine,
and other body fluids. Such tests are
used to make diagnoses and to screen
for a disease and to monitor its pro-
gress. The most common biochemical
tests are performed on
blood
, and they
include
liver function tests
and
kidney
B
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