blood vesselsA general term given to
arteries, veins, and capillaries (see cir-
culatory system).
blue babyAn infant with a cyanotic (blu-
ish) complexion, especially of the lips
and tongue, caused by a relative lack of
oxygen in the blood. This is usually due
to a structural defect of the heart or the
major arteries leaving the heart. Such
defects may need to be corrected surgi-
cally (see heart disease,congenital).
blurred visionIndistinct or fuzzy visual
images. Blurred vision, which should not
be confused with double vision(diplo-
pia), can occur in 1 eyeor both, for
episodes of varying lengths of time, and
can develop gradually or suddenly. The
usual cause of longstanding blurred
vision is a refractive error such as astig-
matism(unequal curvature of the front
of the eye), hypermetropia(longsighted-
ness), or myopia(shortsightedness), all
of which can be corrected by glasses or
contact lenses. After the age of 40, pres-
byopia(reduced ability to focus on near
objects) becomes more common.
Vision may also be impaired or blurred
as a result of damage, disease, or ab-
normalities of parts of the eye or its
connections to the brain. The most com-
mon causes of blurred vision as a result
of disease are cataractand retinopathy.
blushingBrief reddening of the face
and sometimes the neck caused by
widening of the blood vessels close to
the skin’s surface. Blushing is usually an
involuntary reaction to embarrassment.
In some women, blushing is a feature of
the hot flushes, which occur during the
menopause. Flushing of the face occurs
in association with carcinoid syndrome.
BMIThe abbreviation for body mass
index.
body contour surgerySurgery per-
formed to remove excess fat, skin, or
both, from various parts of the body,
especially the abdomen, thighs, and
buttocks. Abdominal wall reduction,
also known as abdominoplasty, involves
removing excess skin and fat from the
abdomen. With all of these procedures
there is a risk of complications, and the
wound may become infected.
In suction lipectomy (liposuction), a
rigid hollow tube is inserted through
a small skin incision and use to break
up large areas of fat, which can then be
sucked out through the instrument.
Minor irregularities and dimpling of the
skin commonly occur after surgery.
body dysmorphic disorderA psychi-
atric disorder in which a person suffers
intense anxiety about an imagined
defect in part of his or her body.
body imageA person’s perception of
the different parts of his or her own body.
body mass index (BMI)An indicator
of healthy body weight. BMI is calcula-
ted by dividing the weight in kilograms
by the square of the height in metres.
The normal range is 20–25.
body odourThe smell caused by the
action of bacteriaon sweat. It is most
noticeable in the armpits and around
the genital area, where the apocrine
glandscontain proteins and fatty mater-
ials favourable to bacterial growth.
boilAn inflamed, pus-filled area of skin,
usually an infected hair follicle. A more
severe and extensive form of a boil that
involves several hair follicles is a car-
buncle. The usual cause of a boil is
infection with the bacterium STAPHYLO-
COCCUS AUREUS. Recurrent boils may
occur in people with known or unrecog-
nized diabetes mellitus or with other
conditions in which general resistance
to infection is impaired. Treatment may
be with antibiotic drugsbut, if pus is
released surgically, the boil will usually
heal without antibiotics.
bolusA soft mass of chewed food that
is produced by the action of the tongue,
teeth, and saliva. The term bolus is also
used to describe a single dose of a drug
that is rapidly injected into a vein.
bondingThe process by which a strong
tie, both psychological and emotional,
is established between a parent and
newborn child.
bonding, dentalDental techniques that
use plastic resins and acrylic or porcelain
veneers to repair, restore, or improve
the appearance of damaged or defective
teeth. It is sometimes used as an alter-
native to crowning (see crown,dental)
and may also be used as a preventive
technique to protect the teeth.
bone The structural material of the
skeletonthat provides a rigid frameworkBLOOD VESSELS BONE
B