PSYCHOSURGERY
PULMONARY EMBOLISM
psychosurgery Any operation on the
brain that is carried out as a treatment
for serious mental illness. It is per-
formed only as a last resort. Prefrontal
lobotomy
has now been largely replaced
by types of
stereotaxic surgery.
psychotherapy Treatment of mental
and emotional problems by psycho-
logical methods. Patients talk to a ther-
apist
about
their
symptoms
and
problems, with the aim of learning
about themselves, developing insights
into relationships, and changing behav-
iour patterns.
psychotropic drugs Drugs that have
an effect on the mind, including
hallu-
cinogenic drugs, sedative drugs, sleeping
drugs
,
tranquillizer drugs
,
and
anti-
psychotic drugs
.
pterygium A wing-shaped thickening of
the
conjunctiva
that extends from either
side of the eye towards the centre. Ptery-
gium is attributed to prolonged exposure
to bright sunlight and is common in
tropical areas. It is surgically removed if
it threatens vision or causes discomfort.
ptosis Drooping of the upper eyelid. The
condition may be
congenital
,
occur
spontaneously, or be due to injury or
disease, such as
myasthenia gravis
. Pto-
sis is usually due to a weakness of the
levator muscle of the upper eyelid or to
interference with the nerve supply to
the muscle. Severe congenital ptosis is
corrected surgically to avoid the devel-
opment of
amblyopia
.
ptyalism See
salivation, excessive.
puberty The
period
when
secondary
sexual characteristics
develop and the
sexual organs mature. Puberty usually
occurs between the ages of 10 and 15.
(See also
precocious puberty
.)
pubes The pubic hair or the area of the
body covered by this hair.
pubic bone The front part of the fused
bones that form the
pelvis.
pubic lice Small, wingless insects (
PHTHI-
rus pu bis
)
that live in the pubic hair and
feed on blood. Also called crab lice or
crabs, they are usually spread by sexual
contact. A louse has a flattened body,
up to 2 mm across. Female lice lay eggs
(nits) on the hair, where they hatch
about
8
days later. On men, the lice may
also be found in hair around the anus,
on the legs, on the trunk, and even in
facial hair. The bites sometimes cause
itching. Children can become infested
by transmission from parents, and the
lice may live on the eyelids. An insecti-
cide lotion kills the lice and eggs.
Public health A branch of medicine
concerned with prevention of disease
through health education, provision of
clean water supplies, sewage disposal,
safer working conditions, infection con-
trol methods, immunizations, and the
care of pregnant women and young chil-
dren. Public health functions are covered
by many people and agencies, such as
Environmental Health Officers, Medical
Officers of Environmental Health, and
the Public Health Laboratory Service.
pudenda A term that refers to the exter-
nal
genitalia.
pudendal block A type of
nerve block
used to provide pain relief for a
forceps
delivery
. A local anaesthetic (see
anaes-
thesia
,
local
) is injected into either side
of the
vagina
near the pudendal nerve.
puerperal sepsis An infection that origi-
nates in the genital tract within
10
days
after
childbirth
,
miscarriage
, or
abortion
.
Once a common cause of death, it is
now easily treated with
antibiotic drugs.
puerperium The period of time after
childbirth
during which the woman's
uterus
and genitals return to their pre-
pregnancy state.
pulmonary Relating to the lungs.
pulmonary disease, chronic obstruc-
tive A combination of chronic
bronchitis
and
emphysema
, in which there is per-
sistent disruption of air flow into or out
of the lungs. Patients are sometimes
described as either pink puffers or blue
bloaters, depending on their condition.
Pink puffers maintain adequate oxygen
in their bloodstream through an increase
in their breathing rate, and remain
“pink” despite damage to the lungs. How-
ever, they suffer from almost constant
shortness of breath. Blue bloaters are
cyanotic (have a bluish discoloration of
the skin and mucous membranes) be-
cause of obesity, and sometimes
oedema
,
mainly due to heart failure resulting
from the lung damage.
pulmonary embolism Obstruction of
the pulmonary artery or one of its
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