VACCINATION
VAGINAL DISCHARGE
V
vaccination A form of
immunization
in
which killed or weakened
microorg-
anisms,
or inactivated bacterial
toxins,
are introduced into the body, usually by
injection, to sensitize the
immune sys-
tem
(see
vaccine
). If disease-causing
organisms or toxins of the same type
later enter the body, the sensitized
immune system rapidly produces
anti-
bodies
that destroy them.
vaccine A preparation given to induce
immunity
against an infectious disease.
Most vaccines contain the organisms
(or parts of the organisms) against
which protection is sought.
Vaccines are usually given by injection
into the upper arm, but some, such as
the
poliomyelitis
vaccine, may be given
orally. Some vaccines require several
doses, spaced some weeks apart; others
require only
1
dose.
vacuum extraction An obstetric pro-
cedure to facilitate the delivery of a
baby. It may be used if the second stage
of labour (see
childbirth
) is prolonged,
if the mother becomes exhausted, or if
the baby shows signs of
fetal distress
.
Vacuum suction techniques are also
used to perform early
abortions
.
The vacuum
extraction instrument
consists of a suction cup connected to
a vacuum bottle. The suction cup is
placed on the baby's head in the birth
canal, and the vacuum machine sucks
the baby's scalp into the cup. The ob-
stetrician draws the baby out of the
mother's vagina by gently pulling on the
cup with each uterine contraction.
The baby is born with a swelling on
the scalp, but this disappears after a
few days, usually without treatment.
vagina The muscular passage, forming
part of the female
reproductive system
,
between the
cervix
and the external
genitalia.
The vagina has muscular
walls, which are highly elastic to allow
sexual intercourse
and
childbirth
and are
richly supplied with blood vessels.
vaginal bleeding Bleeding, via the
vagi-
na
, that may come from the
uterus
, the
cervix
, or from the vagina itself.
The most common source of bleeding
is the uterus and the most likely reason
for it is
menstruation
. From puberty to
the menopause,
menstrual bleeding
usually occurs at regular intervals. How-
ever, problems may occur with either
the character or the timing of the bleed-
ing (see
menstruation, disorders of
).
Nonmenstrual bleeding from the uterus
may be due to a variety of causes. Hor-
monal drugs, such as
oral contraceptives
,
can cause spotting. Other possible causes
include
endometritis
, endometrial can-
cer (see
uterus, cancer
of), and
fibroids.
In early pregnancy, bleeding may be a
sign of threatened
miscarriage
. Later in
pregnancy, it may indicate
placenta
praevia
or placental abruption
(see
antepartum haemorrhage
).
Bleeding from the cervix may be due
to
cervical erosion
, in which case it may
occur after intercourse.
Cervicitis
and
polyps
may also cause bleeding. More
seriously, bleeding may be a sign of cer-
vical cancer (see
cervix, cancer
of).
A possible cause of bleeding from the
vagina is injury during intercourse,
especially following the menopause,
when the walls of the vagina become
thinner and more fragile. Occasionally,
severe
vaginitis
causes bleeding. Rarely,
vaginal bleeding is caused by cancer
of the vagina.
vaginal discharge The emission of se-
cretions from the
vagina.
Some mucous
secretion from the vaginal walls and
from the cervix is normal in the repro-
ductive years; its amount and nature
vary from woman to woman and at dif-
ferent times in the menstrual cycle (see
menstruation
).
Oral contraceptives
can
increase or decrease the discharge.
Secretions tend to be greater during
pregnancy. Sexual stimulation also pro-
duces increased vaginal discharge.
Discharge may be abnormal if it is
excessive, offensive-smelling, yellow or
green, or if it causes itching. Abnormal
discharge often accompanies
vaginitis
,
and may be the result of infection, as in
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