Crossing over: Exchanging genetic material between two paired chromosomes. Crossing over is a way to recombine the genetic material so that each person (except for identical twins) is genetically unique.
- Crossover study
Crossover study: A type of clinical trial in which the study participants receive each treatment in a random order. With this type of study, every patient serves as his or her own control. Crossover studies are often used when researchers feel it would be difficult to recruit participants willing to risk going without a promising […]
Crotch: A nonmedical term in common usage for the region where the legs come together, the place where the lower limbs divide. The word “crotch” is thought to be related to the word “crutch” since the first crutches were likely fashioned from the crotch of a tree, the place where its limbs divide.
An infection of the larynx, trachea, and bronchial tubes that occurs mainly in children. It is usually caused by viruses but sometimes by bacteria. Symptoms include a cough that sounds like a seal’s bark and a harsh crowing sound during inhalation. A low-grade fever is common. A major concern with croup is difficulty breathing as […]
Crown: 1. In dentistry, the portion of the tooth that is covered by enamel. 2. Also in dentistry, a type of restoration that covers all or most of the natural tooth. 3. In anatomy, the top of the head, as in the crown-rump length of a fetus. 4. In obstetrics, when a generous portion of […]
- Cruciate ligament, anterior
Cruciate ligament, anterior: The knee joint is surrounded by a joint capsule with ligaments strapping the inside and outside of the joint (collateral ligaments) as well as crossing within the joint (cruciate ligaments). These ligaments provide stability and strength to the knee joint. The anterior cruciate ligament (cruciate means shaped like a cross) is in […]