Dictionary

subacute Rather recent onset or somewhat rapid change. In contrast, acute indicates very sudden onset or rapid change, and chronic indicates indefinite duration or virtually no change.

sternum The long flat bone in the upper middle of the front of the chest. The sternum articulates (comes together) with the cartilages of the first seven ribs and with the clavicle (collarbone) on either side. The sternum consists of three parts: the manubrium (the upper segment of the sternum, a flattened, roughly triangular bone),…

steroid One of a large group of chemical substances classified by a specific carbon structure. Steroids include drugs used to relieve swelling and inflammation, such as prednisone and cortisone; vitamin D; and some sex hormones, such as testosterone and estradiol.

steroid abuse Use of substances containing steroids to increase muscle mass. Steroids can have many side effects when misused, including psychiatric problems, liver tumors, reduction in the size of male genitals, sterility, and heart damage.

stethoscope An instrument that is used to transmit low-volume sounds such as a heartbeat (or intestinal, venous, or fetal sounds) to the ear of the listener. A stethoscope may consist of two ear pieces connected by means of flexible tubing to a diaphragm that is placed against the skin of the patient. The stethoscope has…

Stevens-Johnson syndrome A serious systemic (bodywide) allergic reaction with a characteristic rash involving the skin and mucous membranes, including the buccal mucosa (inside of the mouth), conjunctiva, and genital areas. Abbreviated SJS. The disease is due to a hypersensitive (allergic) reaction to one of a number of immunologic stimuli including drugs and infectious agents. Complications…

stiff baby syndrome See hyperexplexia.

stillbirth The birth of a dead baby, the delivery of a fetus that has died before birth for which there is no possibility of resuscitation. The distinction between a stillbirth and a miscarriage is arbitrary. The dividing line has variously set at 20 to 24 weeks of gestation or at a specific weight, such as…

Still’s disease See arthritis, systemic-onset juvenile rheumatoid.

sting, Africanized bee See bee sting, Africanized.

stoma An opening into the body from the outside that is created by a surgeon.

stomach The digestive organ that is located in the upper abdomen, under the ribs. The upper part of the stomach connects to the esophagus, and the lower part leads into the small intestine. When food enters the stomach, muscles in the stomach wall create a rippling motion (peristalsis) that mixes and mashes the food. At…