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.
Updated March 27, 2016. A carcinogen is any substance or agent that causes cancer. It does so by altering the cellular metabolism or by damaging DNA in our cells, interfering with normal cellular processes. The identification of substances in the environment that cause people to become ill with cancer helps in prevention efforts.