ABDOMEN
A
abdomen
The region of the body between the
chest and the pelvis. The abdominal cav-
ity
is
bounded
by
the
ribs
and
diaphragm above, and by the pelvis
below, with the spine and abdominal
muscles forming the back, side, and
front walls. The abdominal cavity con-
tains
the
liver,
stomach,
intestines,
spleen, pancreas, and kidneys. In the
lower abdomen, enclosed by the pelvis,
are the bladder, rectum, and, in women,
the uterus and ovaries.
STRUCTURE
The spine, pelvis, and ribs provide
attachments for the layers of muscle
that make up
the abdominal walls.
There is a layer of fat between these
muscles and the skin. The inner surface
of the abdominal muscles is covered by
a
thin
membrane, the
peritoneum,
which also covers the organs, such as
the pancreas and kidneys, that are fixed
to the back wall. Folds of peritoneum
also cover the mobile organs, such as
the stomach and intestines.
abdomen, acute
The medical term for persistent, severe
abdominal pain, of sudden onset, that is
usually associated with spasm of the
abdominal muscles, vomiting, and fever.
CAUSES
The most common cause of an acute
abdomen is
peritonitis
(inflammation of
the membrane that lines the abdomen);
underlying causes include
appendicitis
,
abdominal injury, or perforation of an
internal organ as a result of disorders
such as
diverticular disease
(the presence
of small, protruding pouches in the
intestinal wall) or
peptic ulcer
.
SYMPTOMS
Acute abdomen commonly begins as a
vague pain in the centre of the abdomen
that gradually localizes to a particular
region of the body, depending on the
condition. For example, pain is felt on
the right side of the body in appendicitis.
DIAGNOSIS AND TREATMENT
An acute abdomen requires urgent medi-
cal
investigation
usually
comprising
detailed questioning about the condi-
tion, a physical examination, laboratory
tests, and imaging procedures such as
ultrasound scanning.
The
investigation
may also involve a
laparoscopy
(internal
examination using a rigid or flexible
viewing tube) or a
laparotomy
(surgical
exploration of the abdomen). Treatment
depends on the underlying cause.
abdominal
Relating to the
abdomen
.
abdominal hysterectomy
The
surgical removal of the uterus
(womb)
through an incision in the
abdomen (see
hysterectomy).
abdominal pain
Discomfort in the abdominal cavity.
Symptoms
accompanying
abdominal
pain may include belching, nausea, vom-
iting, rumbling and gurgling noises,
and flatulence (wind).
CAUSES
Mild abdominal pain is common and is
often due to excessive alcohol intake,
eating unwisely, or an attack of
diar-
rhoea.
Pain in the lower abdomen is
common during menstruation but may
occasionally be due to a gynaecological
disorder such as
endometriosis
(in which
fragments of uterine lining are present
in abnormal sites within the abdomen).
Cystitis
(inflammation of the bladder) is
another common cause of pain or dis-
comfort in the lower abdomen. Bladder
distension due to urinary obstruction
may also cause abdominal pain.
Abdominal colic is the term used for
pain that occurs every few minutes as
one of the internal organs goes into
muscular spasm. Colic is an attempt by
the body to overcome an obstruction
such as a stone or an area of inflamma-
tion. The attacks of colic may become
more severe and may be associated with
vomiting (see
abdomen, acute).
A
peptic ulcer,
which is associated
with an increase in the amount of acid
formed in the stomach, often produces
recurrent gnawing pain. Other possible
causes of abdominal pain are infection,
such as
pyelonephritis
(infection of the
kidneys) and
pelvic inflammatory disease
(infection of the internal female repro-
ductive organs), and
ischaemia
(a lack
of blood supply), as occurs when a
volvulus
(twisting of the intestine) obs-
tructs blood vessels. Tumours affecting
an abdominal organ can cause pain.
Abdominal pain may also have a psy-
chological cause, such as anxiety.
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