Voluntary vs Involuntary Muscles

Team Biology at Examples.com
Created by: Team Biology at Examples.com, Last Updated: April 25, 2024

Voluntary vs Involuntary Muscles

The human body boasts over 600 muscles, constituting approximately 35% of our body mass. These muscles are essential for movement and are categorized based on our ability to control them consciously. Voluntary muscles, such as those in our arms, are under our direct control and respond to conscious commands—think of moving your hand to catch a ball or bending your arm. In contrast, involuntary muscles operate without our conscious input. These muscles are crucial for automatic bodily functions, such as heartbeats and the digestion process, where smooth muscle in the digestive tract helps move food via peristalsis. Both types of muscles are vital, each fulfilling specialized roles that enable various body functions, seamlessly integrating into our daily lives without the need for constant awareness.

Difference between Voluntary and Involuntary muscles

You can control voluntary muscles, such as those in your arms and legs. They are long, tube-shaped, and contain multiple nuclei. These muscles attach to your bones and skin and help you move by contracting and relaxing. The brain and the somatic nervous system control these muscles, allowing you to perform actions like walking, picking up objects, and smiling. However, because they exert a lot of effort, voluntary muscles can become tired and need breaks to recover.

Involuntary muscles operate without your conscious control and are present in many internal organs like your heart and stomach. There are two types:

  • Smooth Muscles: These muscles, which are spindle-shaped and lack nuclei, appear in the walls of hollow organs such as your stomach and blood vessels. They move food through your digestive system and blood through your vessels by contracting slowly and rhythmically.
  • Cardiac Muscles: Located solely in your heart, these muscles work continuously without tiring, controlled by the autonomic nervous system, to maintain consistent blood circulation.
Difference between Voluntary and Involuntary muscles
FeatureVoluntary MusclesInvoluntary Muscles
DefinitionMuscles that can be controlled consciously.Muscles that operate without conscious control.
ControlUnder conscious control.Automatically controlled by the autonomic nervous system.
Types of MusclesMainly skeletal muscles.Smooth muscles and cardiac muscles.
LocationAttached to bones and mainly found in arms, legs, and the body’s external parts.Found in the walls of internal organs such as stomach, intestines, and blood vessels; also includes the heart.
FunctionResponsible for movements like walking, grabbing, talking, and facial expressions.Manage functions like digestion, blood flow, and respiration.
AppearanceStriated with a regular pattern of light and dark bands.Non-striated (smooth muscles) and striated (cardiac muscles).
Speed of ContractionFast and forceful contractions.Slower and sustained contractions.
FatigueTends to fatigue easily.Designed for endurance, rarely fatigues.
ExamplesMuscles in arms like biceps and triceps; muscles in legs like quadriceps.Stomach muscles, muscles in the walls of blood vessels, heart muscles.
StimulationUsually stimulated by the nervous system through voluntary signals.Stimulated automatically or through hormonal or involuntary neural signals.
Regeneration AbilityLimited regeneration ability; relies on muscle hypertrophy.Varies; smooth muscles can regenerate better than skeletal muscles.
Response to ExerciseIncreases in size and strength with exercise.Does not significantly change in size with exercise, but function can improve.

Key Differences and Similarities Between Voluntary and Involuntary Muscles


  1. Control:
    • Voluntary Muscles: You control these muscles with your thoughts. For example, you choose to move your legs or arms.
    • Involuntary Muscles: These muscles work on their own without you thinking about them. They handle important tasks like your heartbeat and digestion.
  2. Location and Function:
    • Voluntary Muscles: These mainly include the muscles attached to your bones that enable you to move, such as walking or lifting objects.
    • Involuntary Muscles: These muscles exist inside organs such as the heart and stomach. They work all the time to keep you alive by doing things like pumping blood or moving food through your digestive system.
  3. Response to Stimuli:
    • Voluntary Muscles: These muscles respond when you want them to, like when you need to jump or catch something.
    • Involuntary Muscles: These muscles react automatically to keep your body’s internal processes running smoothly, without you having to think about it.


  1. Composition and Mechanism:
    • Both types of muscles are made up of fibers that tighten and relax, although they look different under a microscope.
  2. Nervous System Interaction:
    • Both types are connected to the nervous system. Voluntary muscles listen to the central nervous system, and involuntary muscles follow commands from the autonomic nervous system.
  3. Role in Health and Disease:
    • Both types are vital for keeping you healthy. They are involved in everything from moving around to making sure your blood and digestion work as they should. Problems with either type of muscle can lead to serious health issues.


What are the difference between voluntary and involuntary muscles?

Voluntary muscles are consciously controlled, like arm and leg muscles. Involuntary muscles operate automatically, such as heart and digestive muscles.

What are 5 examples of involuntary muscles?

Examples include the heart muscle, stomach muscles, intestinal muscles, bladder muscles, and muscles in blood vessel walls.

What is the difference between voluntary and involuntary motor muscles?

Voluntary motor muscles are consciously controlled for actions like walking. Involuntary motor muscles function autonomously, regulating internal processes.

What are the three types of muscles voluntary or involuntary?

The three types of muscles are skeletal (voluntary), smooth (involuntary), and cardiac (involuntary).

What are 5 voluntary and involuntary muscles?

Voluntary: biceps, triceps, quadriceps, hamstrings, and facial muscles. Involuntary: cardiac muscle, smooth muscles in intestines, bladder, respiratory muscles, and muscles in arteries.

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