Liha töötlemine
The striations arise from the alternating,
or banded, appearance because different protein dense A-bands and less dense I-bands
regions have different refractive properties. within the myofibril. Bisecting the I-bands
The light bands have a consistent index of are dark lines known as Z-lines. The structure
refraction (isotropic). Therefore, these bands between two Z-lines is the sarcomere. In a
are called I-bands in reference to this isotro- relaxed muscle cell, the distance between
pic property. The dark band appears dark two Z-lines (and thus the length of the sarco-
because it is anisotropic and is thus called the mere) is approximately 2.2 μm. A single
A-band. myofibril is made up of a large number of
The myofibrils are abundant in skeletal sarcomeres in series. The length of the myo-
annaabi.ee 
