to prevent sperm reaching the ova.
Female sterilization is usually per-
formed by laparoscopy, which involves 2
small incisions in the abdomen. Some-
times it is done by minilaparotomy, in
which a single incision is made in the
pubic area. The fallopian tubes are
sealed using clips or by cutting and
tying. The operations have a lowfailure
rate. Fertility can sometimes be restored
after sterilization using microsurgery.
sterilization, maleSee vasectomy.
sternumThe long, narrow, flat plate of
bone at the front of the chest. The ster-
num has 3 parts: an upper, triangular
portion (manubrium); a long middle part
(body); and, at the lower end, a small,
leaf-shaped projection (xiphoid process).
The upper manubrium articulates with
the inner ends of the clavicles. The ribs
are attached to the sides of the manubri-
um and body by cartilage. Between the
manubrium and body is a symphysis
joint, allowing slight movement when
the ribs rise and fall during breathing.
Great force is required to fracture the
sternum. The main danger of such an
injury is the possibility that the broken
bone may be driven inwards, damaging
the heart, which lies behind the sternum.
steroid drugsA group of drugs includ-
ing corticosteroid drugsand anabolic
steroids (see steroids, anabolic).
steroids, anabolicDrugs that have an
anabolic (protein-building) effect similar
to testosterone. Anabolic steroids build
tissue, promote muscle recovery after
an injury,and strengthen bones. They
are used to treat
some types of
anaemia. Anabolic
steroids are often
abused by athletes.
Possible adverse
effects of the drugs
include acne, oede-
ma, damage to the
liver and adrenal
glands, infertility,
impotence in men,
and virilization in
women.
stethoscope An
instrument that is
used for listeningstenosisNarrowing of a duct, canal,
passage, or tubular organ.
stentA rigid tube that is surgically inser-
ted to open up or keep open any body
canal that may have become narrowed or
closed up due to disease. Stents are used
to open narrowed coronary arteries in
heart disease. They are also used to
relieve blockages caused by a tumour, for
example in the oesophagusor pancreas.
sterculiaA bulk-forming laxativeused to
treat constipation. It is especially useful
when stools are small and hard. Stercu-
lia should only be used if fibre intake
cannot be increased; adequate fluid
intake must be maintained to avoid in-
testinal obstruction. Side effects may
include flatulence, bloating, and gastro-
intestinal obstruction or impaction.
stereotaxic surgeryBrain operations
carried out by inserting delicate instru-
ments through a surgically created hole
in the skull and guiding them, with the
aid of CT scanning, to a specific area.
Stereotaxic procedures can be used to
treat pituitary tumours; for a brain biopsy;
or to destroy small areas of the brain to
treat disabling neurological disorders.
sterilityThe state either of being germ-
free or of permanent infertility.
sterilizationThe complete destruction
or removal of living organisms, usually to
prevent spreadof infection; any proce-
dure that renders a person infertile (see
sterilization, female; vasectomy).
sterilization, femaleA usually perma-
nent method of contraceptionin which
the fallopian tubes are sealed in order
STENOSIS STETHOSCOPE
STERILIZATION, FEMALE S
Clip blocking
fallopian tube
Fallopian tube
UterusSITES OF INCISION LAPAROSCOPIC CLIP STERILIZATIONOvaryCervixVagina