Bma Illustrated Medical Dictionary

entrance to the larynx(voice-box). The

epiglottis is usually upright to allow air

to pass through the larynx and into the

rest of the respiratory system. During

swallowing, it tilts downward to cover

the entrance to the larynx, preventing

food and drink from being inhaled.

epiglottitisA potentially life-threaten-

ing infection causing inflammation and

swelling of the epiglottis. Epiglottitis is

now rare due to routine immunizationof

infants against HAEMOPHILUS INFLUENZAE,

the causative bacterium.

epilepsyA tendency to have recurrent

seizures. In many people with epilepsy,

the cause is unclear, although a genetic

factor may be involved. In other cases,

seizures may be the result of brain dam-

age from head injury, birth trauma,

brain infection (such as meningitisor

encephalitis), brain tumour, stroke, drug

intoxication, or a metabolic disorder.

Many people with epilepsy do not

have any symptoms between seizures.

Some people experience an aura shortly

before. In some cases, a stimulus such

as a flashing light triggers a seizure.

Epileptic seizures may occur more fre-

quently in times of illness or stress.

Epileptic seizures can be classified in-

to two groups: generalized and partial.

Generalized seizures cause loss of con-

sciousness and may affect all areas of

the brain. There are two types: grand

mal and absence (petit mal) seizures.

During a grand mal seizure, there may

be an aura initially, then the body

becomes stiff and consciousness is lost;

breathing may be irregular or may stop

briefly, then the body jerks uncontrol-

lably. The person may be disorientated

for hours afterwards and have no mem-

ory of the event. Prolonged grand mal

seizures are potentially life-threatening.

Absence seizures occur mainly in chil-

dren. Periods of altered consciousness

last for only a few seconds and there are

no abnormal movements of the body.

This type of seizure may occur hundreds

of times daily.

Partial seizures are caused by abnor-

mal electrical activity in a more limited

area of the brain. They may be simple or

complex. In simple partial seizures, con-

sciousness is not lost and an abnormal

twitching movement, tingling sensa-

tion, or hallucinationof smell, vision, or

taste occurs, lasting several minutes. In

complex partial seizures, also known as

temporal lobe epilepsy, conscious con-

tact with the surroundings is lost. The

sufferer becomes dazed and may behave

oddly. Typically, the person remembers

little, if any, of the event.

Diagnosis is made from examination

of the nervous system and an EEG. CT

scanningor MRIof the brain and blood

tests may also be carried out. Anticon-

vulsant drugsusually stop or reduce the

frequency of seizures. Surgery may be

considered if a single area of brain

damage is causing the seizures. Epilep-

sy that develops during childhood may

disappear follow-

ing adolescence.

epiloiaSee tuber-

ous sclerosis.

epinephrineAn

alternative name

for adrenaline.

epiphoraSee wa-

tering eye.

epiphysisThe end

section of a long

bone (such as the

femur) separated

from the diaph-

ysis(shaft) by the

epiphyseal plate.

During childhood and adolescence, the

ephiphyseal plate is made of cartilage

but is gradually replaced by bone.

EPILEPSY EPIPHYSIS

E

Epiglottis

Tongue

Larynx

Vocal cords

Trachea

Oesophagus

EPIGLOTTIS

EPIPHYSIS

Diaphysis

ADULT LONG BONE

Epiphysis

Epiphyseal

plate