Webster's New World Medical Dictionary

particularly if there is profound weakness and mus-
cle atrophy (wasting), surgery is done to avoid per-
manent nerve damage.
carrier test
A test designed to detect carriers of
a gene for a recessive genetic disorder. For exam-
ple, carrier testing is done for the sickle cell trait,
thalassemia trait, and Tay-Sachs gene.
cartilage
Firm, rubbery tissue that cushions
bones at joints. A flexible kind of cartilage makes up
other parts of the body, such as the larynx and the
outside parts of the ears.
casein
The main protein found in milk and other
dairy products.
cast 1
A protective shell of plaster and bandage
that is molded to protect a broken or fractured limb
as it heals. 
2
An abnormal mass of dead cells that
forms in a body cavity. For example, casts of cells
that form in the tubules of the kidneys are some-
times detected in urine samples.
casting
The application of a molded orthopedic
appliance, usually composed of plaster or fiber-
glass, to immobilize part or all of a limb for the pur-
pose of healing injured tissues.
casting, serial
The use of successive casts to
reshape deformed or spastic limbs or contracted
joints.
castration
Removal or destruction of the sex
glands. The term is usually used in reference to the
testicles, but it also can apply to the ovaries.
CAT scan
Computerized axial tomography scan.
CAT scanning is a painless X-ray test in which a com-
puter generates cross-section views of a patient’s
anatomy. It can identify normal and abnormal struc-
tures, and it can be used to guide procedures.
Iodine-containing contrast material is sometimes
used in CAT scanning. A patient who is allergic to
iodine or contrast materials and is scheduled to have
a CAT scan should notify the physician and the radi-
ology staff about the allergy. Also known as CT scan.