between self-image and how others see
one. Psychotherapytreats neurosis by
changing a person’s self-image.
self-injuryThe act of deliberately injur-
ing oneself. Self-mutilation most often
occurs in young adults, many of whom
are also drug or alcohol abusers, and is 3
times more common in women. It may
take the form of cutting the wrists or
burning the forearms with cigarettes. In
some, it is a means of dealing with stress,
such as that caused by child abuse.
More unusual forms of self-harm, such
as mutilating the genitals, are usually
due to psychosis. Self-destructive biting
is a feature of Lesch–Nyhan syndrome,
a rare metabolic disorder.
selegilineA drug used in the treatment
of Parkinson’s disease, either alone (in
the disease’s early stage) or with levo-
dopa. Selegiline is also used to treat the
symptoms of parkinsonism due, for ex-
ample, to repeated head injury; it is not
used if the symptoms are drug-induced,
however. Side effects may include nau-
sea, vomiting, diarrhoea or constipation,
dry mouth, and sore throat.
semenFluid produced by the male on
ejaculation. It is composed of fluid from
the seminal vesicles, fluid from the pros-
tateand Cowper’s glands, and sperm.
semen, blood in theA usually harmless
condition in which a small amount of
blood is present in the semen. Occasion-
ally, there is an underlying cause (such as
an infection or, very rarely, cancer) that
requires treatment. Blood in the semen
may also occur after a prostate biopsy.
semicircular canalA structure in the
inner earthat plays a role in balance.
There are 3 semicircular canals in each
ear, at right angles to each other, and
connected via a chamber called the
vestibule. The fluid-filled canals contain
small hairs that detect movement and
acceleration, and transmit information
to the brain via the vestibular nerve.
seminal fluid analysis Analysis of
sperm concentration, shape, and motility
(ability to move). It is used to investigate
male infertilityand is also done some
weeks after vasectomyto ensure that
the semen no longer contains sperm.
seminal vesicleOne of a pair of sacs
that lie behind the bladder in the male
and produce seminal fluid, which is
mixed with sperm to make up semen
(see reproductive system, male).
seminomaSee testis, cancer of.
senile dementiaSee dementia.
senile purpuraA skin condition in which
areas of the skin develop a purplish or
reddish-brown appearance due to bleed-
ing of small blood vessels underneath.
Senile purpura is a disease of middle to
old age and is more common in women.
senilityA term meaning old age or, more
commonly, the decline in mental ability
that may occur in old age.
sennaA laxative drugobtained from the
leaves and pods of the Arabian shrubs
CASSIA ACUTIFOLIAand CASSIA ANGUSTIFO-
LIA, which stimulates bowel contractions.
It may colour the urine brown or red.
sensate-focus techniqueA method
taught to couples who are experiencing
sexual difficulties caused by psycholog-
ical rather than physiological factors. The
aim of the technique is to make both
partners more aware of pleasurable
bodily sensations, and to reduce anxi-
ety about performance. It is particularly
effective in treating loss of sexual desire
(see sexual desire, inhibited), or inability
to achieve orgasm (see orgasm, lack of),
and in helping men to overcome impo-
tence or premature ejaculation (see
ejaculation, disorders of).
sensationA feeling or impression that
has entered consciousness.The senses
convey information, about the externalSELF-INJURY SENSATION
S
SEMINAL VESICLE
Urethra Bladder Vas deferens UreterEpididymis Seminal
vesicleEjaculatory
duct