College of Massage Therapists of British Columbia (CMTBC) Practice Exam

How are skeletal muscles classified in terms of their structure?

1. Striated and involuntary

2. Non-striated and voluntary

3. Striated, voluntary, and multinucleated

4. Non-striated, involuntary, and multinucleated

The correct answer is: Striated, voluntary, and multinucleated

Skeletal muscles are classified as striated, voluntary, and multinucleated, making this classification accurate. The term "striated" refers to the appearance of skeletal muscle fibers, which have a striped or banded look due to the arrangement of actin and myosin filaments. This striation is characteristic of skeletal muscles and distinguishes them from smooth muscles, which are non-striated. Skeletal muscles are also categorized as voluntary because they are under conscious control. Unlike involuntary muscles, which function automatically (such as the heart or digestive muscles), we can intentionally contract and relax skeletal muscles to perform movements. Furthermore, skeletal muscle fibers are multinucleated, meaning each muscle cell contains multiple nuclei. This characteristic is a result of the developmental process of skeletal muscle cells, where multiple precursor cells fuse together to form a single fiber, allowing for efficient coordination of function and repair. Together, these features—striated appearance, voluntary control, and multinucleation—provide a clear understanding of the unique structural classification of skeletal muscles.