disorders, and to help confirm a diag-
nosis of multiple sclerosis.
Ewing’s sarcomaA rare malignant
form of bone cancer. It arises in a large
bone, usually the femur, tibia, humerus,
or a pelvic bone, and spreads to other
areas at an early stage. The condition is
most common in children aged 10–15.
An affected bone is painful and tender.
It may also become weakened and frac-
ture easily. Other symptoms include
weight loss, fever, and anaemia.
The sarcoma is diagnosed by X-rays
and a biopsy. If cancer is found, the
whole skeleton is examined by X-rays
and radionuclide scanning, and the
lungs viewed by CT scanning, to deter-
mine if, and how far, the cancer has
spread. Treatment is with radiotherapy
and anticancer drugs. If the cancer has
not spread, the outlook is good.
examination, physicalThe part of a
medical consultation in which the doc-
tor looks, feels, and listens to various
parts of the patient’s body to assess the
patient’s condition or to gather infor-
mation to help make a diagnosis.
Most examinations include palpation,
by which the doctor examines relevant
parts of the body for signs such as
swelling, tenderness, or enlargement of
organs. In some cases, percussionof the
chest, or other parts of the body, may
be performed by tapping with the fin-
gers and then listening to the sound
produced. Auscultationmay be used to
listen to blood flow through arteries
and sounds made by the heart and
lungs. The doctor may take the pulse or
blood pressure, examine the eyes and
ears, and assess the strength and coor-
dination of the muscles.
exchange transfusionA treatment for
haemolytic disease of the newborn, in
which the infant’s blood is replaced
with rhesus negative donor blood (see
rhesus incompatibility). It is used to
treat dangerously high levels of bilirubin
in the blood and the severe anaemia
which result from the condition.
excimer laserA laserused to reshape
the corneato correct myopia(short
sight) or hypermetropia(long sight) by
removing very thin layers of tissue from
the corneal surface (see LASIK;PRK).excisionSurgical cutting out of dis-
eased tissue, such as a breast lump,
from surrounding healthy tissue.
excoriationInjury to the surface of the
skin or a mucous membranecaused by
physical abrasion, such as scratching.
excretionDischarge of waste material
from the body, including the by-prod-
ucts of digestion, waste products from
the repair of tissues, and excess water.
The kidneysexcrete excess nitrogen
in the urinein the form of urea, along
with excess water, salts, some acids,
and most drugs. The liverexcretes bile,
which contains waste products and bile
pigments formed from the breakdown
of red blood cells. Some of the bile is
passed from the body in the faeces. The
large intestineexcretes undigested food,
some salts, and excess water in the
form of faeces. The lungsdischarge car-
bon dioxide and water vapour into the
air. Sweat glandsexcrete salt and water
onto the surface of the skin as a method
of regulating the body’s temperature.
exenterationThe surgical removal of
all organs and soft tissue in a body cavi-
ty, usually to arrest the growth of a
cancer. It is sometimes used in ophthal-
mologywhen the eye and the contents
of the eye orbit are removed.
exerciseThe performance of any physi-
cal activity that improves health or that
is used for recreation or for the correc-
tion of physical injury or deformity (see
physiotherapy). Different types of exer-
cise have different effects on the body.
During aerobic exercise, such as jogging
or swimming, the heart and lungs work
faster and more efficiently to supply the
muscles’ increased demand for oxygen;
regular aerobic exercise improves the
condition of both the cardiovascular and
respiratory systems. Exercises such as
weight training increase muscle strength
and endurance. Activities such as yoga
and pilates improve flexibility.
Regular aerobic exercise usually leads
to a reduction in blood pressure. It also
results in an increased amount of high-
density lipoprotein (HDL) in the blood,
which is thought to help protect against
atherosclerosisand myocardial infarc-
tion. Exercise can relieve the symptoms
of peripheral vascular diseaseand ofEWING’S SARCOMA EXERCISEE