Where is the nucleus of a skeletal muscle fiber located?

Where is the nucleus of a skeletal muscle fiber located?

• A. Nucleus of a neuron
• B. Nucleus of skeletal muscle fiber
• C. Nucleus of an adipocyte
• D. Nucleus of a smooth muscle cell

Answer: (B)

Skeletal muscle fibers are multinucleated cells formed by the fusion of precursor cells, so each fiber contains many nuclei. In mature fibers, these nuclei sit peripherally, just beneath the sarcolemma (the cell membrane), along the length of the fiber. This peripheral placement leaves the central cytoplasm free for the long contractile apparatus and lets nearby nuclei efficiently produce proteins and RNAs needed across the fiber. The nuclei belong to the skeletal muscle fiber itself, not to other cell types such as neurons, adipocytes, or smooth muscle cells.

Skeletal muscle fibers are multinucleated cells formed by the fusion of precursor cells, so each fiber contains many nuclei. In mature fibers, these nuclei sit peripherally, just beneath the sarcolemma (the cell membrane), along the length of the fiber. This peripheral placement leaves the central cytoplasm free for the long contractile apparatus and lets nearby nuclei efficiently produce proteins and RNAs needed across the fiber. The nuclei belong to the skeletal muscle fiber itself, not to other cell types such as neurons, adipocytes, or smooth muscle cells.