Bma Illustrated Medical Dictionary

acarboseA drug that is used to treat
type 2 diabetes mellitus. Acarbose acts
on enzymes in the intestines, inhibiting
the digestion of starch and therefore
slowing the rise in blood glucoselevels
after a carbohydrate meal.
accessory nerveThe 11th cranial nerve.
Unlike the other cranial nerves, most of
the accessory nerve originates from the
spinal cord.The small part of the nerve
that originates from the brain supplies
many muscles of the palate, pharynx
(throat), and larynx (voice box). Damage
to this part of the nerve may cause diffi-
culty in speaking and swallowing. The
spinal part of the nerve supplies large
muscles of the neck and back, notably
the sternomastoid andtrapezius. Dam-
age to the spinal fibres of the nerve
paralyses these muscles.
accidental deathDeath that occurs as
a direct result of an accident. A high pro-
portion of deaths in young adults,
particularly among males, are acciden-
tal. Manyof these deaths are due to
road traffic accidents, drowning, or drug
overdose.Falls in the home and burning
or asphyxiation due to fire are common
causes of accidental death in elderly
people. Fatal accidents at work have
become less common with the intro-
duction of effective safety measures.
accommodationAdjustment, especially
the process by which the eye adjusts
itself to focus on near objects. At rest,
the eye is focused for distant vision,
when its lens is thin and flat. To make
focusing on a nearer object possible,
the ciliary muscle of the eye contracts,
which reduces the pull on the outer rim
of the lens, allowing it to become thicker
and more convex.
With age, the lens loses its elasticity.
This makes accommodation more and

more difficult and results in a form of

longsightedness called presbyopia.

acebutololA beta-blocker drugused to

treat hypertension, angina pectoris, and

certain types of arrhythmiain which the

heart beats too rapidly.

ACE inhibitor drugsA group of vaso-

dilator drugsused to treat heart failure,

hypertension, and diabetic nephropathy.

ACE (angiotensin converting enzyme) in-

hibitors are often prescribed with other

drugs such as diuretic drugsor beta-

blocker drugs. Possible side effects

include nausea, loss of taste, headache,

dizziness, and dry cough.

acetaminophen An analgesic drug

more commonly known as paracetamol.

acetazolamideA drug that is used in

the treatment of glaucomaand, occa-

sionally, to prevent or treat symptoms

of mountain sickness. Possible adverse

effects includelethargy, nausea, diar-

rhoea, and impotence.

acetic acidThe colourless, pungent, org-

anic acid that gives vinegar its sour

taste. In medicine, acetic acid is an

ingredient of antiseptic gels that are

used for certain vaginal infections.

acetylcholineA type of neurotransmit-

ter(a chemical that transmits messages

between nerve cells or between nerve

and muscle cells). Acetylcholine is the

neurotransmitter found at all nerve-

muscle junctions and at many other

sites in the nervous system. The actions

of acetylcholine are called cholinergic

actions, and these can be blocked by

anticholinergic drugs.

acetylcholinesterase inhibitors A

group of drugs that are used in the

treatment of mild to moderate dementia

due to Alzheimer’s disease, in which

there is a deficiency of the neuro-

transmitter acetylcholine in the brain.

ACARBOSE ACETYLCHOLINESTERASE INHIBITORS

A

Light rays from
near object

Flattened

lens

Point of

focus

Rounded

lens bends

the light

Point of

focus

Ciliary

muscle

ACCOMMODATION

NEAR FOCUS DISTANT FOCUS

Light rays from

distant object

Ciliary

muscle