Question

In skeletal muscle, the central part of the dark band without the thin filaments is called:

• A. Z line
• B. Sarcomere
• C. Hensen’s disc
• D. Krause’s membrane

Hint:

The visibility of the H zone varies with muscle contraction and is most apparent when the muscle is relaxed.

Answer 1

The Correct Option is C

To solve the problem, we need to identify the part of the skeletal muscle described in the statement.

1. Understanding the Question:
The statement mentions the central part of the dark band (A band) in skeletal muscle, which lacks the thin filaments. This is referring to the region where only the thick filaments (myosin) are present.

2. Analyzing the Options:
- Z line (Option A): The Z line is the boundary between sarcomeres, but it is not the central part of the dark band.
Sarcomere (Option B): A sarcomere is the functional unit of muscle contraction, but it refers to the entire structure that includes both the dark and light bands.
Henson's disc (Option C): This is the correct answer. The central part of the A band in skeletal muscle, where there is only thick myosin filaments, is called the Henson's disc.
Krause's membrane (Option D): This term is not relevant to muscle structure and is incorrect in this context.

3. Conclusion:
Based on the description and the analysis of the options, the correct term for the central part of the dark band without the thin filaments is:

Final Answer:
The correct option is (C) Henson's disc.