PEPTIDE
PERICARDIUM
P
(vomiting of blood) and
melaena,
and is
a medical emergency. Chronic bleeding
may cause iron-deficiency
anaemia.
Rare-
ly, an ulcer may perforate the wall of the
digestive tract and lead to
peritonitis
.
An ulcer is usually diagnosed by an
endoscopy
of the stomach and duode-
num; less commonly, a barium meal (see
barium X-ray examination)
is performed.
Tests will be carried out to see whether
the individual is infected with the
HELI-
cobacter
bacterium. If this is the case,
a combination of
antibiotics
and an
ulcer-
healing drug
will be given. A further test
may be done to check that treatment
has been successful. If
Helicobacter
is
not detected - for example, in ulcers
caused by
nonsteroidal anti-inflammatory
drugs
(NSAIDs) - treatment is with
pro-
ton pump inhibitors
or
H2-blockers,
and
the NSAIDs will be stopped. Surgery is
now rarely needed for peptic ulcers,
except to treat complications such as
bleeding or perforation.
peptide A protein fragment consisting
of 2 or more
amino acids.
Peptides that
consist of many linked amino acids are
known as polypeptides; chains of poly-
peptides are called
proteins
. In the
body, peptides occur in forms such as
hormones
and
endorphins
.
perception The interpretation of a sen-
sation. Information is received through
the 5 senses (taste, smell, hearing, vis-
ion, and touch) and organized into a
pattern by the brain. Factors such as
attitude, mood, and expectations affect
the final interpretation.
Hallucinations
are false perceptions that occur in the
absence of sensory stimuli.
percussion A diagnostic technique in-
volving tapping the chest or abdomen
with the fingers and listening to the
sound produced to deduce the condi-
tion of the internal organs. (See also
examination, physical.)
percutaneous A medical term meaning
through the skin.
perforation A hole made in an organ
or tissue by disease or injury.
peri- A prefix meaning around.
perianal
haematoma A
haematoma
under the skin around the anus.
pericarditis Inflammation of the
peri-
cardium
, which often leads to chest pain
and fever. There may also be an increased
amount of fluid (
effusion
) in the pericar-
dial space, which may restrict the heart.
Long-term inflammation can cause con-
strictive pericarditis, a condition in which
the pericardium becomes scarred, thick-
ens, and contracts, interfering with the
heart's action.
Causes of pericarditis include infection;
myocardial infarction
; cancer spreading
from another site; and injury to the
pericardium. The disorder may accom-
pany
rheumatoid arthriti
s,
systemic lupus
erythematosus
, and
kidney failure
.
Pericarditis causes pain behind the
breastbone, and sometimes in the neck
and shoulders. There may also be fever.
Constrictive pericarditis causes
oedema
of the legs and abdomen.
Diagnosis is made from a
physical ex-
amination
and an
E cG
and
chest X-rays
or
echocardiography
. If possible, treat-
ment is aimed at the cause.
Analgesic
drugs
or
anti-inflammatory drugs
may
be given. If an effusion is present, fluid
may be drawn off through a needle. In
constrictive pericarditis, part of the peri-
cardium may be removed.
pericardium The membranous bag that
surrounds the
heart
and the roots of the
major blood vessels that emerge from
it. The pericardium has 2 layers separat-
ed by a space called the pericardial
space, which contains a small amount
of fluid that lubricates the heart.
STRUCTURE OF HEART
440
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