A dental assistant. hold a current Arizona Board-approved certificate in radiology. To obtain a certificate, one must: 1a. Pass the national DANB Radiation Health and Safety (RHS) exam, AND. 1b. Receive the Arizona Radiologic Proficiency Certificate, issued by DANB, or. 2a.
Parkinson's disease (PD) is a type of movement disorder. It happens when nerve cells in the brain don't produce enough of a brain chemical called dopamine. Sometimes it is genetic, but most cases do not seem to run in families. Exposure to chemicals in the environment might play a role.
Parkinson's Disease. Parkinson's disease is a brain disorder that occurs when neurons in the area of the brain called the substantia nigra begin to die. This interferes with the production of the chemical dopamine, which aids in muscle movement.Symptoms begin to appear when about 80 percent of the dopamine-producing cells are damaged.he main symptoms of Parkinson's include tremors, slow movements, stiffness and balance problems. While Parkinson's is not curable, there are medications that mimic dopamine and help with slowness, tremors and stiffness.