The H-zone in the skeletal muscle fibre is due to : [NEET 2013]a)The c...
Central part of thick filament, not overlapped by thin filaments is called the ‘H’ zone. ‘H’ zone is also called Hensen’s Line.
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The H-zone in the skeletal muscle fibre is due to : [NEET 2013]a)The c...
Explanation:
The H-zone is a light region in the center of the A-band of a sarcomere in skeletal muscles. It is due to the absence of overlap between the actin and myosin filaments in this region.
The correct answer is option B, which states that the H-zone is the central gap between actin filaments extending through myosin filaments in the A-band.
To understand this better, let's go over the structure of a sarcomere:
- A sarcomere is the basic unit of a muscle fiber, consisting of actin and myosin filaments.
- Actin filaments are thin filaments that are attached to the Z-discs at the ends of the sarcomere. They extend towards the center of the sarcomere, but do not overlap with the myosin filaments in the H-zone.
- Myosin filaments are thick filaments that are located in the center of the sarcomere, partially overlapping with the actin filaments.
- The A-band is the dark region in the sarcomere where the myosin filaments are located. It includes the H-zone, which is the light region in the center of the A-band.
Therefore, the H-zone is due to the absence of overlap between actin and myosin filaments in this region, creating a gap or light region in the center of the A-band. This allows the myosin filaments to slide past the actin filaments during muscle contraction.
In summary, the H-zone in skeletal muscle fibers is due to the central gap between actin filaments extending through myosin filaments in the A-band.
The H-zone in the skeletal muscle fibre is due to : [NEET 2013]a)The c...
H-zone refers to the portion of the sarcomere only containing the myosin. Hence, it does not include the part where actin filament is present, so it refers to the central gap between the actin filaments.
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