Bma Illustrated Medical Dictionary

there is usually a gain in weight. When
less energy is consumed than is spent,
weight is usually lost as the stores are
used up. (See also nutrition; obesity.)
enfluraneA liquid mixed with oxygen
and inhaled as a vapour to induce and
help maintain general anaesthesia (see
anaesthesia, general). Rarely, enflurane
may cause arrhythmia.
engagementThe descent of the head
of the fetusinto the mother’s pelvis. In a
woman’s first pregnancy, engagement
usually occurs by the 37th week but in
subsequent pregnancies it may not
occur until labour begins.

engorgementOverfilling of the breasts
with milk. Engorgement is common a
few days after childbirth. It causes the
breasts and nipples to become swollen
and tender, and can make breastfeeding
difficult. The problem can be relieved by
expressing milk.
enkephalinsA group of small protein
molecules produced in the brainand by
nerve endings elsewhere in the body.
Enkephalins have an analgesic effect
and are also thought to affect mood.
Enkephalins are similar to endorphins
but have a slightly different chemical
composition and are released by differ-
ent nerve endings.

enophthalmosA sinking inwards of the

eyeball. Enophthalmos is most often

caused by fracture of the eye socket or

shrinkage of the eye due to the forma-

tion of scar tissue following injury.

enteric-coated tabletA tablet whose

surface is covered with a substance that

is resistant to the action of stomach

juices. Enteric-coated tablets pass un-

dissolved through the stomach into the

small intestine, where the covering dis-

solves and the contents are absorbed.

Such tablets are used either when the

drug might harm the stomach lining or

when the stomach juices may affect the

efficacy of the drug.

enteric feverAn alternative name for

typhoid feveror paratyphoid fever.

enteritisInflammation of the small in-

testine. The inflammation may be the

result of infection, particularly giardiasis

and tuberculosis, or of Crohn’s disease.

Enteritis usually causes diarrhoea. (See

also gastroenteritis; colitis.)

enteritis, regionalAnother name for

Crohn’s disease.

enterobiasisA medical term for thread-

worm infestationof the intestines.

enterostomyAn operation in which a

portion of small or large intestine is

joined to another part of the gastroin-

testinal tract or to the abdominal wall,

for example in a colostomy or ileostomy.

enterotoxinA type of toxinreleased by

certain bacteriathat inflames the intes-

tinal lining, leading to diarrhoea and

vomiting. Enterotoxins cause the symp-

toms of staphylococcal food poisoning

(see staphylococcal infections) and

cholera. (See also endotoxin; exotoxin.)

entrapment neuropathyA condition,

such as carpal tunnel syndrome, in

which local pressure on a nervecauses

muscle pain, numbness, and weakness

in the area that the nerve supplies.

entropionA turning in of the margins

of the eyelidsso that the lashes rub

against the corneaand the conjunctiva.

Entropion is sometimes present from

birth, especially in overweight babies. It

is common in the elderly, due to weak-

ness of the muscles around the lower

eye. Entropion of the upper or lower lid

may be caused by scarring, for example

that due to trachoma.

ENFLURANE ENTROPION

E

BEFORE ENGAGEMENT

AFTER ENGAGEMENT

Head

Head

sits in

pelvis

Uterus

ENGAGEMENT

Pelvis