Bma Illustrated Medical Dictionary

to heal, or that would leave tethering or

unsightly scars. A skin graft is often

used in the treatment of burns or some-

times for nonhealing ulcers. A piece of

healthy skin is detached from one part

of the body and transferred to the

affected area. New skin cells grow from

the graft and cover the damaged area.

In a meshed graft, donor skin is

removed and made into a mesh by cut-

ting. The mesh is stretched to fit the

recipient site; new skin cells grow to fill

the spaces in the mesh. In a pinch graft,

multiple small areas of skin are pinched

up and removed from the donor site.

Placed on the recipient site, they gradu-

ally expand to form a new sheet of

healthy skin. (See also skin flap.)

skin patchSee transdermal patch.
skin peeling, chemicalA cosmetic
operation in which the outer layers of
the skin are peeled away by the applica-
tion of a caustic paste in order to remove
freckles, acne scars, delicate wrinkles, or
other skin blemishes.
skin tagA harmless, small, brown or
flesh-coloured flap of skin that may
appear spontaneously or as a result of
poor healing of a wound.

skin testsProcedures for determining the

body’s reaction to various substances by

injecting a small quantity of the sub-

stance under the skin or by applying it

to the skin (usually on patches). Patch

tests are used in the diagnosis of contact

allergic dermatitis. They can also be used

to test immunity to certain infectious

diseases (such as in the tuberculin test).

skin tumoursA growth on or in the skin

that may be cancerous (see skin cancer)

or noncancerous. Keratosesand squa-

mous papillomasare common types of

noncancerous tumour; other types inc-

lude sebaceous cysts, cutaneous horns,

keratoacanthomas, and haemangiomas.

skullThe bony skeleton of the head,

which rests on the 1st cervical vertebra.

The skull protects the brain, houses the

special sense organs, provides points of

attachment for muscles, and forms part

of the respiratory and digestive tracts.

The 8 bones of the cranium encase the

brain. The skull’s facial skeleton includes

the nasal and cheek bones, maxilla, and

mandible. All except the mandible are

fixed together by immovable joints.

skull, fracture ofA break in 1 or more of

the skullbones caused by a head injury.

In most skull fractures, the broken bones

are not displaced and there are no com-

plications. Severe injury may result in

bone fragments rupturing blood vessels

in the meninges, or, more rarely, tearing

the meninges, leading to brain damage.

A fracture without complications usually

heals by itself; damage to brain struc-

tures often requires neurosurgery.

skull X-rayA technique for providing

images of the skull. X-rays of the skull

are usually taken after a head injuryto

look for a fracture or foreign body, or to

evaluate disorders that affect the skull.

slapped cheek syndromeAn alterna-

tive name for fifth disease, an infection

in children caused by parvovirus in

which the cheeks become reddened.

SLEThe abbreviation for the disorder

systemic lupus erythematosus.

sleepThe natural state of lowered con-

sciousness and reduced metabolism.

There are 2 types of sleep: REM (rapid

eye movement) and NREM (nonrapid eye

movement) sleep, which alternate in

cycles. NREM sleep consists of 4 stages

SKIN PATCH SLEEP

SKIN GRAFT

MESHED SKIN GRAFT

Recipient

site

Pinch

graft

Recipient

site

Meshed

graft

S

PINCH SKIN GRAFT

Healthy

skin