Dictionary

thigh The thick, muscular portion of the leg that extends from the hip to the knee. The thigh has only one bone, the femur, which is the largest bone in the human body.

thiamine Vitamin B1, which acts as a coenzyme in the metabolism of the body. In its active form, thiamine participates in a range of biochemical reactions, including certain reactions that are important to carbohydrate metabolism. Deficiency of thiamine leads to the disease beriberi. See also Appendix C, “Vitamins.”

thermometer In medicine, a device used to measure the temperature of the human body. There are many types of medical thermometers, including oral thermometers (placed under the tongue), rectal thermometers (placed within the rectum), multipurpose thermometers (placed under the tongue, in the rectum, or under the armpit), eardrum thermometers (placed inside the ear), and basal…

therapy The treatment of disease. Therapy is synonymous with treatment.

therapeutic cloning Cloning designed as therapy for a disease. In therapeutic cloning, the nucleus of a cell, typically a skin cell, is inserted into a fertilized egg whose nucleus has been removed. The nucleated egg begins to divide repeatedly to form a blastocyst. Scientists then extract stem cells from the blastocyst and use them to…

therapeutic abortion An abortion that is brought about intentionally. Also known as induced abortion.

therapeutic Relating to therapeutics, the branch of medicine that is concerned specifically with the treatment of disease. The therapeutic dose of a drug is the amount needed to treat a disease.

T-helper cell See T-4 cell.

thelarche The time that breast development starts in girls.

thalidomide syndrome A congenital malformation syndrome that is caused by maternal exposure to thalidomide. Although thalidomide syndrome is epitomized by the flipper-like limbs (phocomelia), thalidomide causes a wide range of birth defects, including absence of ears with deafness; defects of the muscles of the eye and of the face; absence or hypoplasia (underdevelopment) of the…

thalidomide baby An infant who is affected by prenatal exposure to the drug thalidomide. In 1998, thalidomide again became available to treat certain conditions, and there is concern that babies may be born with the thalidomide syndrome as they were in the 1950s and early 1960s.

thalidomide A drug (brand name: Thalomid) that was used in the 1950s and early 1960s to treat morning sickness in pregnancy. The use of thalidomide had tragic results: When taken during pregnancy, it can cause a syndrome of congenital malformations in the developing fetus. Thalidomide was then not approved for marketing in the US and…