ACSM Personal Trainer Certification Practice Exam

What type of muscle is cardiac muscle classified as?

1. Voluntary muscle tissue

2. Involuntary muscle tissue

3. Skeletal muscle tissue

4. Striated muscle tissue

The correct answer is: Involuntary muscle tissue

Cardiac muscle is classified as involuntary muscle tissue because it operates autonomously, meaning it contracts without the need for conscious control. This involuntary nature is crucial for its function in the heart, allowing it to continuously pump blood throughout the body without conscious thought. Unlike voluntary muscles, which are controlled by the somatic nervous system and are under voluntary control, cardiac muscle is controlled by the autonomic nervous system, which regulates bodily functions that occur automatically. In addition to being involuntary, cardiac muscle is also striated, characterized by a banded appearance due to the organized arrangement of actin and myosin filaments. However, its classification as involuntary is the primary distinguishing factor when comparing it to other muscle types, such as skeletal muscle, which is voluntary and controlled consciously. Therefore, recognizing cardiac muscle as involuntary is essential for understanding its role and function in the human body.