Bma Illustrated Medical Dictionary

lumbar vertebra, and its narrow lower

part with the coccyx. The sides of the

sacrum are connected by the sacroiliac

jointsto each ilium. The sacrum lies in

the centre back of the pelvis. Disorders

affecting the sacrum include sacralgia,

spondylolisthesis, and sacralization. (See

also spine, disorders of.)

sadismThe tendency or practice of deriv-

ing pleasure, particularly sexual pleasure,

from the infliction of suffering or pain

on others. (See also sadomasochism.)

sadomasochismThe tendency or prac-

tice of deriving sexual pleasure by

inflicting pain (see sadism) and receiving

abuse (see masochism); one trait usually

predominates. The term also describes

a relationship in which one partner is

very dominant and one is submissive.

SADSThe abbreviation for seasonal affec-

tive disorder syndrome.

safe periodSee contraception, natural

methods of.

safer sexPreventive measures to reduce

the risk of sexually transmitted infections;

for example, maintaining a monogamous

sexual relationship and using a condom.

salbutamolA bronchodilator drugused

to treat asthma, chronic bronchitis, and

emphysema. It is also occasionally used

in the prevention of premature labour.

salicylate drugsA group of drugs,

such as aspirinand benorilate, with anti-

inflammatory, fever-reducing, and mild

analgesicaction. Overdose causes hyper-

ventilation, tinnitus, sweating, abnormal

bleeding, biochemical disturbances, and,

in severe cases, convulsions and coma.

salicylic acidA keratolytic drugused to

treat skin disorders, such as dermatitis,

eczema, psoriasis, dandruff, ichthyosis,

acne, warts, and callosities (see callus,

skin), and also sometimes to treat fungal

infections. Side effects are few and may

include irritation and dryness of the skin.

salineA solution of salt (sodium chlo-

ride). “Normal saline” solution has the

same concentration as body fluids and

may be given by intravenous infusionto

replace fluids lost in severe dehydration.

salivaThe slightly alkaline fluid that is

secreted into the mouth by the salivary

glandsand the mucous membranes lin-

ing the mouth. Saliva contains the

enzyme amylase, which helps to break

sacA bag-like organ or body structure.

saccharinAn artificial sweetener.

sacralgiaPain in the sacrumcaused by

pressure on a spinal nerve, usually due

to a disc prolapse. Rarely, it may caused

by bone cancer. (See also back pain.)

sacralizationFusion of the 5th (lowest)

lumbar vertebrawith the upper sacrum. It

may be present at birth, in which there

are usually no symptoms. Surgery may

be performed to treat a disc prolapseor

spondylolisthesis. (See also spinal fusion.)

sacroiliac jointOne of a pair of rigid

jointson each side of the body that form

an interface between the sacrumand the

ilium. They can be strained, usually by

childbirth or overstriding, causing pain

in the lower back and buttocks. They can

also become inflamed (see sacroiliitis.)

sacroiliitisInflammation of a sacroiliac

joint.Causes include ankylosing spondyli-

tis, rheumatoid arthritis, Reiter’s syndrome

or arthritis associated with psoriasis. The

main symptom is pain in the lowerback,

buttocks, groin, and back of the thigh.

Treatment is with nonsteroidal anti-

inflammatory drugs.

sacrumThe large triangular bone in the

lower spine. The sacrum’s broad upper

part articulates with the 5th (lowest)

SAC SALIVA

S

S

SACRUM

Sacroiliac

joint

Sacrum

Coccyx

Ilium

PELVIS