Which type of muscle is the most common in the human body

Which type of muscle is the most common in the human body? A. Skeletal muscle B. Cardiac muscle C. Smooth muscle D. Autonomic muscle

The correct answer and explanation is:

The correct answer is A. Skeletal muscle.

Explanation:

The human body contains three primary types of muscle tissue: skeletal muscle, cardiac muscle, and smooth muscle. Each type has distinct characteristics and functions.

1. Skeletal Muscle
   • These muscles are attached to bones by tendons and are responsible for voluntary movements like walking, lifting, and facial expressions.
   • They are striated (have a striped appearance under a microscope) due to the organized arrangement of muscle fibers.
   • Skeletal muscles are the most abundant muscle type in the human body, making up about 40-50% of total body weight.
   • They are controlled consciously by the somatic nervous system, meaning you decide when to move them.
2. Cardiac Muscle
   • Found only in the heart, cardiac muscle is also striated but involuntary—you do not consciously control it.
   • It contracts rhythmically and continuously to pump blood throughout the body.
   • Though vital, cardiac muscle is much less abundant than skeletal muscle because it is limited to the heart.
3. Smooth Muscle
   • Found in the walls of internal organs such as the intestines, blood vessels, bladder, and uterus.
   • Unlike skeletal and cardiac muscles, smooth muscle is non-striated and involuntary.
   • It helps move substances through internal passageways (e.g., food in the digestive tract, blood in arteries).
   • Although smooth muscle is widespread, its overall mass in the body is less than skeletal muscle.
4. Autonomic Muscle
   • This is not a recognized muscle type. The term “autonomic” relates to the autonomic nervous system, which controls involuntary functions, including those of smooth and cardiac muscles, but it is not a distinct muscle type.

Summary:

• Skeletal muscle is the most common muscle type in the human body by mass and volume.
• It is primarily responsible for voluntary movements and posture.
• Cardiac and smooth muscles are crucial but less abundant overall.

This makes A. Skeletal muscle the correct answer.