Which statement best describes skeletal muscle?

Which statement best describes skeletal muscle?

• A. It is weak and contracts involuntarily.
• B. It is not striated and has a single nucleus.
• C. It contracts slowly and is primarily smooth in function.
• D. It is strong, quick, and under voluntary control.

Answer: (D)

Skeletal muscle is the type you can control to move your bones. It is organized into long, cylindrical fibers with striations (bands) and multiple nuclei, reflecting its highly structured sarcomeres that allow quick and powerful contractions. This type of muscle is innervated by the somatic (voluntary) nervous system, so you can decide when to move it. That combination—strong, quick contractions and voluntary control—fits skeletal muscle best. In contrast, smooth muscle (found in walls of hollow organs) contracts slowly and is involuntary, and cardiac muscle (heart) is striated like skeletal muscle but is involuntary and has intercalated discs for rhythmic, automatic beating.

Skeletal muscle is the type you can control to move your bones. It is organized into long, cylindrical fibers with striations (bands) and multiple nuclei, reflecting its highly structured sarcomeres that allow quick and powerful contractions. This type of muscle is innervated by the somatic (voluntary) nervous system, so you can decide when to move it.

That combination—strong, quick contractions and voluntary control—fits skeletal muscle best. In contrast, smooth muscle (found in walls of hollow organs) contracts slowly and is involuntary, and cardiac muscle (heart) is striated like skeletal muscle but is involuntary and has intercalated discs for rhythmic, automatic beating.