Bma Illustrated Medical Dictionary

marble bone diseaseSee osteopetrosis.

march fractureA break in one of the

metatarsal bones(the long bones in

the foot) that is caused by running or

walking for long distances on a hard

surface. The fracture results in pain,

tenderness, and swelling. However, it

may not show on X-raysuntil callus

(new bone) starts to form. Treatment for

a march fracture is rest and, occasion-

ally, immobilization in a plaster cast.

(See also stress fracture.)

Marfan’s syndromeA rare genetic dis-

order of connective tissue (material

that holds body structures together)

that results in skeletal, heart, and eye

abnormalities. Features of Marfan’s syn-

drome usually appear after age 10.

Affected people are very tall and thin,

with long, spidery fingers and weak liga-

ments and tendons. The chest and

spine are often deformed and the lens

of the eye may be dislocated. The heart

or aortais often abnormal.

marijuanaThe flowering tops and dried

leaves of the Indian hemp plant CANNABIS

SATIVA, containing the active ingredient

THC (tetra-hydrocannabinol). The leaves

are usually smoked but can be drunk as

tea or eaten in food. Physical effects of

marijuana include dry mouth, mild red-

dening of the eyes, slight clumsiness,

and an increased

appetite. The main

subjective feelings

are usually of calm-

ness and wellbeing,

but depression oc-

curs occasionally.

Large doses may

cause panic, fear of

death, and illusions.

In rare cases, true

psychosis occurs,

with paranoid de-

lusions, confusion,

and other symp-

toms, which usually

disappear within a few days. Regular

use of marijuana may lead to a more

permanent state of apathy and loss of

concern (a condition that is known as

amotivational syndrome).

marriage guidanceSee relationship

counselling.

marrow, boneSee bone marrow.

marsupializationA surgical procedure

used to drain some types of abscessor

cystand to prevent further abscesses.

Marsupialization is used to treat certain

types of cysts affecting the pancreasand

liver, and cysts affecting the Bartholin’s

glandsat the entrance to the vagina.

masculinizationSee virilization.

masochismA chronic desire to be phys-

ically, mentally, or emotionally abused.

The term masochism is used to refer to

the achievement of sexual excitement

by means of one’s own suffering through

activities such as bondage, flagellation,

and verbal abuse. (See also sadism;

sadomasochism.)

massageRubbing and kneading areas

of the body, usually with the hands.

Massage increases the blood flow and

relaxes muscles; it may be used to re-

lieve muscle spasm, treat muscle injury,

and reduce oedema. Although massage

is most effective when carried out by

someone else, self-massage can allevi-

ate pain caused by muscle tension.

mastalgiaThe medical term for pain in

the breast.

mast cellA type of cell that plays an

important part in allergy. In an allergic

response, mast cells release histamine.

mastectomyThe surgical removal of all

of the breast, usually performed to treat

breast cancer. Mastectomy may be used

for extensive breast cancer or for multi-

ple cancerous tumours. For smaller

cancers, lumpectomyor quadrantectomy

may be appropriate.

A mastectomy involves the removal of

all of the breast tissue and usually

some or all of the lymph nodesin the

armpit. Cells from the lymph nodes are

examined to determine whether can-

cerous cells may have spread. The

operation is performed under general

anaesthesiaand usually requires a stay

in hospital of several days. Plastic

surgeryto reconstruct the breast may

be carried out at the same time as the

mastectomy or at a later time (see

mammoplasty).

Treatment with radiotherapyis often

given after surgery, especially if the

cancer has spread to lymph nodes. It

usually starts a month after surgery and

MARBLE BONE DISEASE MASTECTOMY

M

MARIJUANA

MARIJUANA LEAF