OVARY, DISORDERS OF
OVULATION
Treatment is by surgical removal of the
growth or as much cancerous tissue as
possible. This usually involves
salpingo-
oophorectomy
and
hysterectomy
followed
by
radiotherapy
and
anticancer drugs.
ovary, disorders of Diseases and ab-
normalities of the ovaries can occur for
various reasons. Absence of ovaries, or
their failure to develop normally, is rare
and is usually due to a chromosomal
abnormality (see
Turner's syndrome).
Oophoritis (inflammation of an ovary)
may result from infections such as
gon-
orrhoea
or
pelvic inflammatory disease.
Ovarian cysts
are common and usually
noncancerous.
Polycystic ovary
syndrome
is due to an imbalance of sex hormones.
Ovarian cancer (see
ovary, cancer
of)
occurs mainly in women over 50. Ovar-
ian failure causes premature
menopause
in about 5 per cent of women.
ovary,
polycystic A condition, also
called Stein-Leventhal syndrome, that
is characterized by oligomenorrhea or
amenorrhoea
(scanty or absent periods),
infertility
,
hirsutism
(excessive hairiness),
and
obesity.
Often, there are multiple
ovarian cysts.
Most women with poly-
cystic ovaries begin menstruation at a
normal age, but after a year or two peri-
ods become highly irregular and then
cease. Hirsutism and obesity occur in
about 50 per cent of cases.
The condition results from an imbal-
ance of two
gonadotrophin hormones:
follicle-stimulating hormone (FSH) and
luteinizing hormone (LH). This hormon-
al imbalance is associated with raised
levels of
testosterone
and
oestrogen.
Treatments include clomifene and
oral
contraceptives.
Polycystic ovaries are
often associated with high oestrogen
levels in the body, which increase the
risk of endometrial cancer (see
uterus,
cancer of);
treatment with progesterone
may be recommended for this problem.
overbite Overlapping of the lower front
teeth
by the upper ones. A slight degree
of overbite is normal as the upper jaw is
larger than the lower jaw. In
malocclu-
sion
, overbite may be greater than
normal or the lower teeth may project
in front of the upper teeth.
overbreathing A common name for
hyperventilation
.
overcrowding, dental Excessive crowd-
ing of the
teeth
so that they are unable
to assume their normal positions in the
jaw. Dental overcrowding is commonly
inherited and may occur because the
teeth are too large for the jaw or the jaw
is too small to accommodate the teeth.
Premature loss of primary molar (back)
teeth can cause the permanent teeth
beneath them to move out of position
and crowd the teeth further forward.
Overcrowded teeth may lead to
maloc-
clusion
or may prevent certain teeth from
erupting through the gum (see
impac-
tion, dental
). They can be difficult to clean,
increasing the risk of dental decay (see
caries, dental
) and
periodontal disease
.
Teeth may need to be extracted to
allow room for others. Usually an
ortho-
dontic appliance
is fitted to the remaining
teeth to position them correctly.
over-the-counter (OTC) drug A drug
that can be bought without a prescrip-
tion at a chemist's or other store.
overuse injury Also called
repetitive
strain injury
a term, for any injury caused
by repetitive movement of part of the
body. Symptoms include pain and stiff-
ness in the affected joints and muscles.
Examples include
epicondylitis
: painful
inflammation of one of the bony promi-
nences at the elbow, caused by the pull
of the attached forearm muscles during
strenuous activities (see
golfer's elbow;
tennis elbow).
Overuse injuries of the fin-
gers, thumb, and wrist joints may affect
assembly-line and keyboard workers, and
musicians; injuries of the neck may affect
violinists. Rest relieves the symptoms.
A change in the technique used during
the activity may prevent recurrence.
overweight See
obesity
.
ovulation The development and release
of an
ovum
(egg) from a follicle within
an
ovary.
During the 1st half of the
menstrual cycle,
follicle-stimulating hor-
mone
(FSH) causes several ova to mature
in the ovary. At mid-cycle,
luteinizing
hormone
(LH) causes 1 ripe ovum to be
released. Signs of ovulation include a
rise in body temperature, changes in the
cervical mucus, and sometimes mild
abdominal pain (see
mittelschmerz).
A
yellow mass of tissue called the corpus
luteum, which forms from the follicle
O
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