Question

The diagram given below represents the histology of a stripped muscle. Which one of the following have the correctly matched label of the parts A, B, C, D, E and F?

• A. A- Sarcoplasm, B- Nucleus, C- Sarcolemma, D- myofibril, E- Dark band, F- Light band
• B. A- Sarcoplasm, B- Light band, C- Myofibril, D- Sarcolemma, E- Nucleus, F- Dark band
• C. A- Light band, B- Sarcoplasm, C- Myofibril, D- Sarcolemma, E- Nucleus, F- Dark band
• D. A- Sarcolemma, B- Nucleus, C- Dark band, D- Light band, E- Sarcoplasm, F- Myofibril

Answer 1

The correct option is C A- Light band, B- Sarcoplasm, C- Myofibril, D- Sarcolemma, E- Nucleus, F- Dark band

• Every muscle fibre is lengthy and cylindrical in shape, which contain many nuclei. The given labelling E is the nucleus.
• The cell membrane of muscle is called as sarcolemma. Given labelling D is sarcolemma.
• Longitudinal section of skeletal muscle shows a distinctive pattern of alternative light and dark bands.
• The dark bands are called as A-band, sometimes contain a pale region in the middle called as H-zone.
• The light staining bands are called as I bands. I bands are intervenned by a thin Z-line. This striated pattern in due to the presence of myofibrils in the sarcoplasm. Here, labelling A and labelling F are light and dark bands respectively, while labelling C is myofibril.
• The segment of a myofibril from Z-line to Z-line is referred to as sarcomere.
• So, the correct answer is 'A- Light band, B- Sarcoplasm, C- Myofibril, D- Sarcolemma, E- Nucleus, F- Dark band'