Answer:True
Explanation:
membranous channel extending inward from muscle fiber membrane are called transverse tubule.
The transverse tubules are extensions of the cell membrane that penetrate into the cytoplasm of muscle cells.
The transverse tubules allowing impulses to penetrate the muscle cell and activate the sarcoplasm reticulum to release stored Calcium ions. Transverse tubules do this by inviginating the cell membrane of muscle fibers
