Glossitis occurs in various forms of
anaemiaand in vitamin B deficiency.
Other causes include infection of the
mouth (especially by herpes simplex),
irritation by dentures, and excessive use
of alcohol, tobacco, or spices. Treat-
ment is for the underlying cause.
Rinsing of the mouth with a salt solu-
tion and good oral hygienemay help.
glossolaliaSpeaking in an imaginary
language that has no actual meaning or
syntax. (See also neologism.)
glossopharyngeal nerveThe ninth
cranial nerve. This nerve performs both
sensory and motor functions. It conveys
sensations, especially taste, from the
back of the tongue, regulates secretion
of saliva by the parotid gland, and con-
trols movement of the throat muscles.
glottisThe part of the larynxthat con-
sists of the vocal cordsand the slit-like
opening between them.
glucagonA hormonethat stimulates
the breakdown of stored glycogeninto
glucoseand is released by the pancreas
when the blood level of glucose is low.
Glucagon is used as an injected drug
in the emergency treatment of people
with diabetes mellituswho are uncon-
scious as a result of low blood glucose.
Nausea and vomiting are occasional
adverse effects.
glucocorticoidsHormonesproduced by
the cortex of the adrenal glandsthat
affect carbohydrate metabolism by in-
creasing the blood sugar level and are
also involved in the body’s response to
physical stress. The main glucocorticoid
is hydrocortisone.
glucosamineA molecule that occurs
naturally as a component of various
substances in the body, including colla-
gen. Glucosamine is also sold as a food
supplement and is recommended to
relieve symptoms of arthritis.
glucoseA simple sugarthat is naturally
present in fruits and is a product of
the digestion of starchand sucrose. It is
the chief source of energy for the body
and is carried to all tissues in the
blood. The term blood sugar refers to
glucose in the bloodstream.
The level of glucose in the blood is
normally kept fairly constant by the
actions of various hormones, notablyinsulin, glucagon, adrenaline, cortico-
steroid hormones, and growth hormone.
An abnormally high blood glucose level
(known as hyperglycaemia) may cause
glucose to be lost into the urine. An
abnormally low blood glucose level is
called hypoglycaemia.
glue earAccumulation of fluid in the
cavity of the middle ear, causing im-
paired hearing. Persistent glue ear is
most common in children. It is often
accompanied by enlarged adenoidsand
frequently occurs with viral respiratory
tract infections, such as the common
cold. Usually both ears are affected. The
lining of the middle ear becomes over-
active, producing large amounts of
sticky fluid, and the eustachian tube
becomes blocked so that the fluid
cannot drain away. The accumulated
fluid interferes with the movement of
the delicate bones of the middle ear.
Glue ear is sometimes first detected by
hearing tests. Examination with an oto-
scope can confirm the diagnosis. In mild
cases, the condition often clears up with-
out specific treatment. If the condition
persists, it may be necessary to insert
grommets, which allow air into the mid-
dle ear and encourage fluid to drain.
Adenoidectomymay also be required.
glue-sniffingSee solvent abuse.
glutaraldehydeA topicalpreparation
for the treatment of warts, particularly
plantar warts. Glutaraldehyde may cause
a rash or irritation and may stain the
skin brown.
glutenA combination of gliadins and
glutenins (types of proteins) formed when
certain cereal flours (notably wheat flour)
are mixed with water. Sensitivity to
gluten causes coeliac disease.
gluten enteropathySee coeliac disease.
gluten intoleranceSee coeliac disease.
gluteus maximusThe large, powerful
muscle in each of the buttocks that
gives them their rounded shape. The glu-
teusmaximus is responsible for moving
the thigh sideways and backwards.
glycerolA colourless syrupy liquid that
has a sweet taste. Glycerol is prepared
from fats and oils; it is an essential con-
stituent of triglycerides(simple fats).
In rectal suppositories, glycerol relieves
constipationby softening hard faeces.GLOSSOLALIA GLYCEROLG