DIGIT
DIOPTRE
acids
.
Fats
are broken down into
glyc-
erol
,
glycerides, and
fatty acids
.
In the mouth, saliva lubricates food and
contains enzymes that begin to break
down carbohydrates. The tongue moulds
food into balls (called boli) for easy swal-
lowing. The food then passes into the
pharynx. From here, it is pushed into
the oesophagus and squeezed down
into the stomach, where it is mixed with
hydrochloric acid and pepsin. Produced
by the stomach lining, these substances
help break down proteins. When the food
has been converted to a semi-liquid con-
sistency, it passes into the duodenum
where bile salts and acids (produced by
the liver) help to break down fats.
Digestive juices released by the pancreas
into the duodenum contain enzymes
that further break down food. Break-
down ends in the small intestine, carried
out by enzymes produced by glands in
the intestinal lining. Nutrients are ab-
sorbed in the small intestine. The residue
enters the large intestine, where water
is absorbed. Undigested matter is ex-
pelled via the rectum and anus as
faeces
.
DIGESTIVE SYSTEM
Pharynx
Salivary
glands
Oesophagus
Stomach
Liver
Rectum
Anus
Pancreas
Gallbladder
Small
intestine
Large
intestine
Appendix
digit
A division, such as a
finger
or
toe
,
located at the end of a limb.
digitalis drugs
A group of drugs that
are extracted from plants belonging to
the foxglove family. They are used to
treat heart conditions, most commonly
atrial fibrillation
.
Those most frequently
used are
digitoxin
and
digoxin
.
digital subtraction angiography
See
angiography
.
digitoxin
A long-acting
digitalis drug
used to treat
heart failure
and certain
types of
arrhythmia
.
digoxin
The most widely used of the
digitalis drugs
.
It is used in the treat-
ment of
heart failure
and certain types
of
arrhythmia
,
such as
atrial fibriilation
.
Blood tests may sometimes be needed
to ensure the correct digoxin dose, esp-
ecially in patients with kidney disease.
An excessive dose may cause headache,
loss of appetite, nausea, and vomiting.
Digoxin occasionally disrupts the nor-
mal heartbeat, causing
heart block
.
dihydrocodeine
A type of
analgesic
drug
. Its side effects include nausea
and vomiting.
dilatation
A condition in which a body
cavity, tube, or opening is enlarged or
stretched due to normal physiological
processes or because of disease. The
term dilatation also refers to proce-
dures for achieving such enlargement,
as in dilatation and curettage.
dilatation and curettage
See
D and C
.
dilation
A term that is sometimes used
as an alternative to
dilatation
.
dilator
An instrument for stretching and
enlarging a narrowed body cavity, tube,
or opening.
diltiazem
A
calcium
channel blocker
used in the treatment of
hypertension
and
angina pectoris
.
Side effects may
include headache, appetite loss, nau-
sea, constipation, and swollen ankles.
dimeticone
A silicone-based substance,
also known as simeticone, that is used
in
barrier creams
and as an antifoaming
agent in
antacid
preparations.
dioptre
A unit of the power of
refraction
(“strength”) of a lens; the greater the
power, the stronger the lens. Lenses
that cause parallel light rays to con-
verge have a positive dioptric number
and are used to correct longsightedness
174
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