Bma Illustrated Medical Dictionary

the tropics but is rare in developed

countries. The antibiotics tetracycline or

erythromycinare effective treatments.

Graves’ diseaseAn autoimmune dis-

order that is characterized by toxic

goitre(an overactive and enlarged thy-

roid gland), excessive production of

thyroid hormones leading to thyrotoxi-

cosis, and exophthalmos.

gravidaThe medical term for a pregnant

woman. The term gravida is often com-

bined with a prefix to indicate the total

number of pregnancies a woman has

undergone (including the present one).

For example, a primigravida is a woman

who is pregnant for the first time.

grayAn SI unit of radiation dosage (see

radiation unit).

greenstick fractureA type of fracture

that occurs when a long bone in the

arm or the leg bends and cracks on one

side only. This type of fracture occurs

only in children, whose bones are still

growing and flexible.

grey matterRegions of the central ner-

vous system consisting principally of

closely packed and interconnected nerve

cell bodies and their branching den-

drites, rather than their filamentous

axons, which make up the white matter.

Grey matter is mostly found in the outer

layers of the cerebrum(the main mass

of the brainand the region responsible

for advanced mental functions) and

deeper regions of the brain, such as the

basal ganglia. Grey matter also makes

up the inner core of the spinal cord.

griefAn intensely painful emotion, usu-

ally caused by loss of a loved one. (See

bereavement.)

gripThe ability of the handto hold

objects firmly. The hand is well adapted

for gripping, with an opposable thumb

(one that is able to touch each of the

fingers), specialized skin on the palm

and fingers to provide adhesion, and a

complex system of muscles, tendons,

joints, and nerves that enables precise

movements of the digits.

Gripping ability can be reduced by any

condition that causes muscular weak-

ness or impairment of sensation in the

palms or fingers (e.g. a strokeor nerve

injury) or by disorders that affect the

bones or joints of the hand or wrist,

such as arthritisor a fracture.

gripeSevere abdominal pain (see colic).

griseofulvinA drug given orally to

treat some fungal infections. Griseoful-

vin is particularly useful for infections

affecting the scalp, beard, palms, soles

of the feet, and nails. Common side

effects are headache, dry mouth, abdom-

inal pain, and photosensitivity. Long-term

treatment with the drug may cause liver

or bone marrow damage.

groinThe hollow between the lower

abdomen and top of the thigh.

groin, lump in theA swelling in the

groin, most commonly due to enlarge-

ment of a lymph node as a result of an

infection (see glands, swollen). Another

common cause is a hernia. Rarely, in

men, an undescended testis may be the

cause (see testis, undescended). Treat-

ment depends on the cause.

groin strainPain and tenderness in

the groinas a result of overstretching

of a muscle, typically while running or

playing sports.The musclescommonly

affected are the adductors and the rec-

tus femoris. Groin strain is usually

treated with physiotherapy, but recovery

may be slow.

grommetA small tube that may be

inserted through an incision in the

eardrumduring surgery to treat glue

ear, usually in children. The grommet

equalizes the pressure on both sides of

the eardrum, permitting mucus to drain

down the eustachiantubeinto the back

of the throat. The tubes are usually

GRAVES’ DISEASE GROMMET

G

Grey matter

Basal ganglia

(grey matter)

White matter

Brain stem

Cerebellum

Spinal cord

SECTION THROUGH BRAIN

GREY MATTER