Bma Illustrated Medical Dictionary

secretion from the stomach lining. Gas-
tric juice contains pepsin, an enzyme that
breaks down protein; hydrochloric acid,
which kills bacteria and creates the opti-
mum pHfor pepsin activity; and intrinsic
factor, which is essential for absorption
of vitamin B 12 in the small intestine. The
gastric lining also secretes mucus to
stop the stomach digesting itself.
The muscular stomach wall produces
rhythmic contractions that churn the food
and gastric juice to aid digestion. Partly
digested food is squirted into the duo-
denum at regular intervals by stomach
contractions and by relaxation of the
ring of muscle at the stomach outlet.
stomachacheDiscomfort in the upper
abdomen. (See also indigestion.)
stomach cancerA malignant tumour
that arises from the lining of the stomach.
The exact cause is unknown, but HELICO-
BACTER PYLORIinfection is thought to be
linked to increased incidence. Other like-
ly factors include smoking and alcohol
intake; diet may also play a part, in par-
ticular eating large amounts of salted or
pickled foods. Pernicious anaemia, a par-
tial gastrectomy, and belonging to blood
group A also seem to increase the risk.
Stomach cancer rarely affects people
under 40 and is more common in men.

There may also be other symptoms indis-

tinguishable from those of peptic ulcer.

Diagnosis is usually made by gastros-

copyor by a barium X-ray examination.

The only effective treatment is total gas-

trectomy. In advanced cases in which the

tumour has spread, radiotherapy and

anticancer drugsmay prolong life.

stomach, disorders of theThe stom-

ach may be affected by various disorders,

including gastrointestinal infections,pep-

tic ulcers, gastritis, pyloric stenosis,

volvulus, polyps, and stomach cancer.

stomach imagingSee barium X-ray

examinations.

stomach pumpSee lavage, gastric.

stomach ulcerA type of peptic ulcer.

stomatitisAny form of inflammation or

ulceration of the mouth.

stonesSmall, hard collections of solid

material within the body. (See also cal-

culus, urinary tract; gallstones.)

stoolAnother word for faeces.

stork markA small, flat, harmless,

pinkish-red skin blemish found in many

newborn babies. Such marks, which may

be temporary, are a type of haeman-

giomaand are usually found around the

eyes and at the nape of the neck.

strabismusSee squint.

strainTearing or stretching of muscle

fibres as a result of suddenly pulling

them too far. There is bleeding into the

damaged area of muscle, causing pain,

swelling, muscle spasm, and bruising.

Treatment may include applying an ice-

pack, resting the affected part, taking

analgesic drugs, and physiotherapy.

strangulationThe constriction, usually

by twisting or compression, of a tube or

passage in the body, blocking blood

flow and interfering with the function of

the affected organ. Strangulation may

occur with a hernia, for example.

Strangulation of the neck causes com-

pression of the jugular veins, preventing

blood from flowing out of the brain, and

compression of the windpipe, which

restricts breathing. The victimloses con-

sciousness, and brain damage and death

from lack of oxygen follow.

stranguryA symptom characterized by

a painful and frequent desire to empty

the bladder, although only a few drops

of urine can be passed. Causes include

STOMACHACHE STRANGURY

S

STOMACH

Oesophagus

Oesophageal
sphincter

Pyloric
sphincter

Duodenum

Ruga

Mucosa

Submucosa

Muscle layers

LOCATION