The Region of the Sarcomere That Always Contains Thin Filaments

Question

The region of the sarcomere that always contains thin filaments is the
A) Z line.
B) M line.
C) H band.
D) A band.
E) I band.

Accepted Answer

The I band is the region of the sarcomere that always contains thin filaments, whereas the H band and A band contain thick filaments (myosin). The Z line is the boundary at the ends of the sarcomere where thin filaments are anchored, and the M line is the center of the sarcomere where thick filaments are anchored.