<Tr> <Th> Code </Th> <Td> TH H2. 00.05. 0.00008 </Td> </Tr> <Tr> <Th> TH </Th> <Td> H2. 00.05. 0.00008 </Td> </Tr> <Tr> <Td_colspan="2"> Anatomical terminology (edit on Wikidata) </Td> </Tr> <P> A sarcomere (Greek sarx "flesh", meros "part") is the basic unit of striated muscle tissue . It is the repeating unit between two Z lines . Skeletal muscles are composed of tubular muscle cells (myocytes called muscle fibers or myofibers) which are formed in a process known as myogenesis . Muscle fibers contain numerous tubular myofibrils . Myofibrils are composed of repeating sections of sarcomeres, which appear under the microscope as alternating dark and light bands . Sarcomeres are composed of long, fibrous proteins as filaments that slide past each other when a muscle contracts or relaxes . </P>

Type of contraction in which muscle fibers do not shorten is called