In vertebrates, skeletal muscle contractions are neurogenic as they require synaptic input from motor neurons to produce muscle contractions. A single motor neuron is able to innervate multiple muscle fibers, thereby causing the fibers to contract at the same time.
periostitis. n. 1. (Anatomy) inflammation of the periosteum.
Polymyositis is a type of chronic inflammation of the muscles related to dermatomyositis and inclusion body myositis. Its name means inflammation of many muscles. The inflammation is predominantly of the endomysium in polymyositis, whereas dermatomyositis is characterized by primarily perimysial inflammation.