Question

question 52
the space between the ends of the two sets of thin filaments in each sarcomere is called the:
a band
m line
h zone
z line

Explanation:

1. Recall sarcomere structure: The sarcomere has thick (myosin) and thin (actin) filaments.
2. Analyze options:

• A band: Contains thick filaments (and overlapping thin filaments), not the space between thin filament ends.
• M line: Middle of A band, holds thick filaments together.
• H zone: Region in A band with only thick filaments, i.e., space between ends of two sets of thin filaments (since thin filaments don't reach the center of A band in relaxed state).
• Z line: Defines sarcomere boundaries, anchors thin filaments.

Thus, the space between thin filament ends in a sarcomere is the H zone.

Answer:

C. H zone