ENEMA
machine. The term “end stage” is used
in relation to many conditions, includ-
ing cancer, advanced kidney failure, and
chronic lung diseases.
enema
A procedure in w hich fluid is passed
into the
rectum
through a tube that has
been inserted into the
anus
.
An enema
may be performed as a treatment, to
prepare the intestine for surgery, or as
an aid to diagnosis.
WHY IT IS DONE
An enema may be given to clear the
intestine of faeces, either to relieve con-
stipation or in preparation for intestinal
surgery. Enemas may also be used to
administer medicine, such as
corticosteroid
drugs
in the treatment of the inflamma-
tory bowel condition
ulcerative colitis
.
A
barium enema is used to diagnose dis-
orders of the large intestine (see
barium
X-ray examinations
) .
HOW
IT
IS DONE
Anaesthesia is not required, although
the procedure may cause slight discom-
fort because
the
fluid stretches
the
intestine. The patient lies on his or her
side w ith the hips raised on a pillow. A
catheter (flexible tube), with a soft, well-
lubricated tip, is gently inserted into the
rectum and the enema fluid, warmed to
prevent a sudden contraction of the
intestine, is slowly introduced through
it. Treatment doses are often packaged
with their own applicators.
energy
The capacity to do work or effect physi-
cal change. Nutritionists use the term to
refer to the fuel content of a food.
There are many different forms of
energy, including light, sound, heat,
chemical, electrical, and kinetic, and
most of them play a role in the body.
For
instance,
the
retina
(the
light-
sensitive inner layer at the back of the
eye) converts light energy to electrical
nerve impulses, making vision possi-
ble. The body’s
muscles
use chemical
energy obtained from food to produce
kinetic energy, movement, and heat.
MEASUREMENT
Energy is measured in units called
cal-
ories
and
joules
.
Because these units are
extremely small, more practical units
used in
dietetics
(nutritional science)
are the kilocalorie (kcal, 1,000 calories)
and kilojoule (kJ, 1,000 joules).
Carbo-
hydrates
and
proteins
provide 4 kcal per
gram (g), whereas
fats
provide 9 kcal
per g (see
metabolism
).
ENERGY STORAGE AND
USE
In general, the energy liberated from
the breakdown of food is stored as
chemical energy in
ATP
(adenosine tri-
phosphate)
molecules.
The
stored
energy is then available to power pro-
cesses that consume energy, such as
muscle contraction or the repair and
maintenance of body structures.
energy requirements
The amount of
energy
needed by an in -
dividual for cell
metabolism,
muscular
activity, and growth. This energy is pro-
vided by the chemical breakdown of
fats,
carbohydrates,
and
proteins
supplied by
food in the diet and by stored
nutrients
in the liver, muscles, and
adipose tissue.
ENERGY EXPENDITURE
Energy is needed to maintain the heart-
beat, lung function, and constant body
temperature. The rate at which these pro-
cesses use energy, while the body is at
rest, is called the basal metabolic rate
(BMR). Any actions, such as movement
or food digestion and absorption, increase
energy expenditure above the BMR.
An individual’s energy requirement
increases during periods of growth and
during
pregnancy
and
breast-feeding.
ENERGY AND
BODY WEIGHT
W hen more energy is ingested (in the
form of food) than is used by the body,
the surplus is stored and there is usually
a gain in weight. W hen less energy is
consumed than is spent, weight is usu-
ally lost as the stores are used up. (See
also
nutrition
;
obesity.)
enflurane
A liquid mixed with
oxygen
and inhaled
as a vapour to induce and help to main-
tain general anaesthesia (see
anaesthesia,
general).
Rarely, enflurane may cause
arrhythmia
(an
abnormality
of
the
rhythm or rate of the heartbeat; see
arrhythmia, cardiac
).
engagement
The descent of the head of the
fetus
into
the mother’s
pelvis.
In a woman’s first
pregnancy, engagement usually occurs
by the 3 7th week but in subsequent
pregnancies
it
may not
occur
until
labour
begins. Rarely, engagement fails to
occur. This may happen, for example, if
the baby’s position in the uterus is
abnormal; if the baby’s head is too big
for the mother’s pelvis; or if there is a
condition known as
placenta praevia
(an
abnormal positioning of the placenta
across the opening of the uterus).
Engelmann’s disease
A rare, progressive, inherited form of
bone
dysplasia
(a growth abnormality).
In affected individuals, the bones become
abnormally long and thick, which usually
results in abnormal stature and, some-
times, in delayed walking (see
walking,
delayed
). There may
also be muscle
wasting, pain or weakness in affected
limbs, delayed
puberty
,
and
hypogonadism
(underactivity of the testes or ovaries).
The disease is inherited in an auto-
somal dominant pattern
(see
genetic
disorders
) and affects more males than
females. It is usually diagnosed in the
first few years
of life. There is no
specific
treatment available,
although
nonsteroidal anti-inflammatory drugs
may
be given to relieve pain.
engorgement
Overfilling
of the breasts with
milk
.
Engorgement is common a few days
after childbirth, when the milk supply
arrives quickly and forcibly. Engorge-
ment causes the breasts and nipples to
become swollen and tender, and can
make
breast-feeding
difficult. The prob-
lem can be relieved by
expressing milk
.
enhancement
The process of augmentation. The term
may be used of improvements made to
body structures or functions, or may
mean increasing the clarity of images in
diagnostic imaging methods. For exam-
ple, immunoenhancement is the process
by w hich the body’s
immune response
is
increased by the use of antibodies (pro-
teins made by the immune system).
enkephalins
A
group
of small
protein
molecules
produced in the
brain
and by nerve end-
ings
elsewhere in the body
(in the
digestive system and adrenal glands, for
example). Enkephalins have an analgesic
(painkilling) effect and are also thought
to affect mood. They are similar to
end-
orphins
but have a slightly
different
chemical composition and are released
by different nerve endings.
enlarged prostate gland
See
prostate, enlarged
.
enophthalmos
A sinking inwards of the eyeball. Enoph-
thalmos is most commonly caused by
fracture of the eye socket or shrinkage
of the eye due to the formation of scar
tissue following injury.
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