In 2015 Illinois will again process all appointment renewals electronically through the National Insurance Producer Registry (NIPR). 1  Appointment renewal date is November 1, 2015. 2  Appointment renewals will be electronically processed through NIPR.
myofibril - one of many contractile filaments that make up a striated muscle fiber. myofibrilla, sarcostyle. sarcoplasm - the cytoplasm of a striated muscle fiber. striated muscle cell, striated muscle fiber - an elongated contractile cell in striated muscle tissue.
The smallest functional unit in a myofibril is a sarcomere. A sarcomere is composed of thin (actin) and thick (myosin) filaments. Actin slides past myosin when the muscle contracts.