Which of the following characteristics defines skeletal muscles?

Skeletal muscles are uniquely defined by several key characteristics that differentiate them from other types of muscle tissue. They are striated, meaning they have a banded appearance due to the arrangement of actin and myosin filaments. This striation is a direct result of the organized structure of the muscle fibers, which allows for efficient contraction.

Additionally, skeletal muscles are voluntary muscles, meaning they can be consciously controlled by the nervous system. This voluntary control is important for activities such as walking, lifting, and other movements that require deliberate effort.

Skeletal muscle fibers are also multinucleated, which is a result of their development. During embryogenesis, myoblasts (muscle precursor cells) fuse to form long, tubular fibers that contain multiple nuclei along their lengths. This multinucleation supports the high metabolic demand and allows for efficient muscle function.

In summary, the defining characteristics of skeletal muscles being striated, voluntary, and multinucleated are essential for their function and reflect the unique nature of this tissue type in the human body.