that is essential for the pro-
duction of red
Folic acid is contained in a
variety of foods, particularly liver and
raw vegetables; adequate amounts are
usually included in a norm al diet.
During pregnancy, folic acid is very
important for fetal growth, the devel-
opment of the nervous system, and the
formation of blood cells. The incidence
neural tube defects
is reduced if a
woman takes folic acid supplements
before conception and during the first
weeks of pregnancy.
Folic acid deficiency is a cause of
duces symptoms such as headaches,
occur during any serious illness or can
be the result of a nutritionally poor
diet, especially in people w ho con-
sume large amounts of alcohol.
folie a deux
A French term that is used to describe
the unusual occurrence of two people
sharing the same psychotic illness (see
Often the two people are
closely related and share one or more
become separated, one of them usually
have been imposed by the dominant,
and genuinely psychotic, partner.
Any form of medical treatment that is
based on popular tradition, such as the
charming of warts or the use of copper
bracelets to treat rheumatism.
A small cavity in the body. For exam-
follicle is a pit in the skin
from w hich a single strand of hair
emerges. Another example is an ovar-
cavity in the
in w hich an
that is pro-
duced by the
and acts on
In women, follicle-
stimulating hormone (FSH) causes an
egg follicle to start maturing in the
ovary in the first week of the menstru-
al cycle, ready for
production in the
testes. FSH is given medically to treat
certain types of
Inflammation of one or more hair fol-
licles as a result of a
Folliculitis can occur almost
anywhere on the skin, but the condition
most commonly affects the neck, arm-
pits, thighs, or buttocks, causing a
it may also affect the bearded area of
the face, producing pustules (see
). Treatment of folliculitis is with
Because the infection is
easily spread, careful hygiene is im por-
tant, and an affected individual should
wash any clothes worn next to the skin
daily in boiling water until the condi-
tion has cleared up.
Inanimate objects (for example, bed
linen, clothing, books, or telephone
receivers) that are not in themselves
harm ful but w hich may be capable of
or parasites and, therefore, of convey-
ing an infection from one person to
another. Fomites principally transmit
respiratory infections, such as
The singular form of the word fomites
is “fomes” .
Either one of two membrane-covered
spaces between the bones of a baby’s
skull. At birth, the skull bones are not
yet fully fused, and two soft areas can
be felt through the scalp. These are the
anterior fontanelle, w hich is diamond-
shaped and usually closes up by age 18
months, and the posterior fontanelle,
w hich is triangular and closes up w ith-
in the first two months.
It is normal for the fontanelles to
become tense and bulge out when a
baby cries. Persistent tension at other
times, however, may indicate an abnor-
accumulation of fluid in the skull). A
sunken fontanelle may be a sign of
If a fontanelle is abnor-
mally large or takes a long time to
close, the cause may be a brain abnor-
mality or a disorder, such as
affecting the skull bones. Early closure
of the fontanelles results in a deform-
Occasionally, a third fontanelle is pre-
sent between the other two; this is a
baby may have extra bones in the ante-
rior fontanelle, but this is not abnormal.
These extra bones fuse into the skull
when the gap between them closes.
Location of the fontanelles
There are two soft areas on the baby’s skull - the
anterior fontanelle is diamond-shaped, the
posterior fontanelle is triangular.
Any substance that is added to food for
improve its acceptability in terms of
taste, colour, or consistency.
TYPES AND USES
Additives fall into five main groups:
those that preserve food; those that
affect texture; those that affect appear-
ance and taste; added nutrients, such as
vitamins; and miscellaneous additives,
such as rising and glazing agents, flour
For further information on the many
different types of food additives, see
the table opposite.
Preservatives, such as sodium nitrate,
growth of bacteria, moulds, and yeasts.
Other additives, such as antioxidants,
can improve the keeping quality of
food by preventing any undesirable
chemical changes w ithin it; for exam-
ple, antioxidants prevent rancidity in
some foods containing fat.
Additives that improve the texture of
stabilizers, and gelling agents. Lecithin,
w hich occurs naturally in all animal and
plant cells, is an emulsifier that is added
to margarine to prevent separation.
The appearance and taste of many
foods and drinks may be improved
through the use of colourings, flavour-
ings, sweeteners, and flavour enhancers.
such as saccharin
and aspartame, may be used instead of
sugar, especially in products that are
aimed at people trying to lose weight.
Many colourings are natural (for exam-
ple, beetroot red).
Certain additives may produce an al-
although this is relatively rare. Some
substances, particularly food colourings