Which type of muscle fiber is characterized by being striated, voluntary, and multinucleated?

• A. Skeletal muscle fiber
• B. Cardiac muscle fiber
• C. Smooth muscle fiber

Answer: (A)

Verified step by step guidance

1. Step 1: Begin by understanding the characteristics of the three types of muscle fibers: skeletal, cardiac, and smooth. Each type has distinct structural and functional features.
2. Step 2: Recall that skeletal muscle fibers are striated, meaning they have a striped appearance under a microscope due to the arrangement of actin and myosin filaments. They are also voluntary, meaning their contraction is consciously controlled, and multinucleated, meaning each fiber contains multiple nuclei.
3. Step 3: Compare skeletal muscle fibers to cardiac muscle fibers. Cardiac muscle fibers are also striated but are involuntary (controlled by the autonomic nervous system) and typically have a single nucleus per cell.
4. Step 4: Contrast skeletal muscle fibers with smooth muscle fibers. Smooth muscle fibers are non-striated, involuntary, and typically have a single nucleus per cell. They are found in the walls of hollow organs like the intestines and blood vessels.
5. Step 5: Based on the characteristics provided in the question (striated, voluntary, and multinucleated), identify that the correct type of muscle fiber is skeletal muscle fiber.