The motor point is usually located at the center of the muscle mass where the motor nerve enters the muscle.
Definition A carcinogen is defined as something that can directly cause cancer. This can be a chemical substance, a virus, or even the medications and radiation we use to treat cancer. While many cancers are caused by a carcinogen or combination of carcinogens, the tendency to develop cancer may also be inherited as part of our genome.
Â· carcinogenesis [kar sin o jenÂ´ eh sis] The process by which normal cells are transformed into cancer cells. Â· carcinoma [kar sih noÂ´ ma] A malignant tumor that arises from skin or the lining of internal body organs, for example, the breast, prostate, lung, stomach or bowel. Carcinomas often invade adjacent tissue and spread to distant organs, including the brain.