acids. Fatsare 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.digitA division, such as a fingeror toe,
located at the end of a limb.
digitalis drugsA 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 digitoxinand digoxin.
digital subtraction angiographySee
angiography.
digitoxinA long-acting digitalis drug
used to treat heart failureand certain
types of arrhythmia.
digoxinThe most widely used of the
digitalis drugs. It is used in the treat-
ment of heart failureand certain types
of arrhythmia, such as atrial fibrillation.
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.
dilatationA 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 curettageSee D and C.
dilationA term that is sometimes used
as an alternative to dilatation.
dilatorAn instrument for stretching and
enlarging a narrowed body cavity, tube,
or opening.
diltiazemA 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.
dimeticoneA silicone-based substance,
also known as simeticone, that is used
in barrier creamsand as an antifoaming
agent in antacidpreparations.
dioptreA 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 longsightednessDIGIT DIOPTREStomachPharynxAnusPancreasOesophagusSalivary
glandsLiverGallbladderAppendixLarge
intestineDIGESTIVE SYSTEMSmall
intestineRectumD