Bma Illustrated Medical Dictionary

more likely to cause a blockage if they

become infected and partly because

children’s eustachhian tubes are shorter

than those of adults.

euthanasiaThe use of medical know-

ledge to end a person’s life painlessly in

order to relieve suffering. Euthanasia is

illegal in the UK.

euthyroidThe term used to describe a

person whose thyroid glandis function-

ing normally, especially someone who

has been successfully treated for either

hypothyroidismor hyperthyroidism.

evening primrose oilAn oil that is

extracted from the seeds of the plant

OENOTHERA BIENNIS, commonly known as

the evening primrose. The oil contains

an anti-inflammatory substance called

gamolenic acid, and is believed by

some to be of benefit in treating eczema

and premenstrual syndrome.

eversionA turning outwards. The term

is used medically to describe a type of

ankle injury or deformity in which the

foot is turned outwards.

evidence-based medicineHealth care

based on evidence, acquired through

expert practice and research, that a par-

ticular test or treatment is appropriate

for an individual patient.

evoked responsesThe tracing of elec-

trical activity in the brain in response to

a specific external stimulus. The proce-

dure is similar to that for an EEG.

The technique is used to check the

functioning of various sensory systems

(such as sight, hearing, or touch). The

information obtained can be used to

reveal abnormalities caused by inflam-

mation, pressure from a tumour, or other

eunuchA man whose testeshave been

removed or destroyed so that he is ster-

ile and lacks male hormones. A male

who has been castrated before puberty

will have broad hips, narrow shoulders,

and undeveloped male secondary sexu-

al characteristics.

euphoriaA state of confident well-

being. Euphoria is a normal reaction to

personal success, but it can also be

induced by drugs, including prolonged

use of corticosteroid drugs. Euphoria

with no rational cause may be a sign of

mania, or brain damage due to head

injury, dementia, brain tumours, or mul-

tiple sclerosis.

eustachian tubeThe passage that runs

from the middle earinto the back of the

nose, just above the soft palate. The

tube acts as a drainage channel from

the middle ear and maintains hearing

by opening periodically to regulate air

pressure. The lower end of the tube

opens during swallowing and yawning,

allowing air to flow up to the middle

ear, equalizing the air pressure on both

sides of the eardrum.

When a viral infection such as a cold

causes blockage of the eustachian tube,

equalization cannot occur, resulting in

severe pain and temporary impairment

of hearing. A person with a blocked

eustachian tube who is subjected to

rapid pressure changes may suffer from

barotrauma. Glue earor chronic otitis

mediamay occur if the tube is blocked,

preventing adequate drainage from the

middle ear. These conditions, which

often result in partial hearing loss are

more common in children. This is partly

because their adenoids are larger and

EUNUCH EVOKED RESPONSES

E

Inner

ear

Outer
ear

Middle

ear

EUSTACHIAN TUBE

Eardrum Eustachian tube

EVENING PRIMROSE OIL

CAPSULES EVENING PRIMROSE