Difference Between Voluntary Muscles and Involuntary Muscles (With Table)

The muscular body of a human being is made of various cells and tissues that combined different forms of muscles that carry out the function of the human body like movement, contraction, and body posture. Out of the various muscles, there are two of them that take part majorly in the functioning of the body and are hence known as Voluntary Muscles and Involuntary Muscles. They are arranged in different parts of body structure and combined with the skeleton system to carry out the tasks of a human body. 

Voluntary Muscles vs Involuntary Muscles

The difference between voluntary Muscles and involuntary Muscles is that voluntary muscles functions according to desire or conscious control, whereas involuntary muscles work according to the nervous system of the body autonomously. This difference enables the muscles to work throughout the body in all situations and make the entire body movement and hold still. 

Voluntary muscles come across as long and multinucleated cells and are also known as skeletal muscles. This is because tendons keep these muscles joined and are composed of cylindrical fibers. Like most muscles, voluntary muscles also carry out the important task of expanding and contracting of body and keep the actions under control. It also allows the body to relax and move accordingly. 

Involuntary muscles or their contraction are maintained by the autonomous nervous system and have a shape that is plan yet striped with branches in the case of cardiac muscles. Muscles are soft tissues, and even involuntary muscles are present in organs like the stomach and intestines. Involuntary muscles also include smooth and cardiac muscles as a part of it. 

Comparison Table Between Voluntary Muscles and Involuntary Muscles

Parameters of Comparison Voluntary Muscles Involuntary Muscles
ShapeVoluntary muscles are long and cylindrical with an unbranched structure. Involuntary muscles are plain, striped with a spindle shape. They are usually small muscles. 
Contraction Control The contraction of voluntary muscles is controlled by the central nervous system or in terms of desires and conscious nature. Contraction Control of involuntary muscles is done by the autonomic nervous system, unlike other muscles. 
Energy High energy requirement for voluntary muscles. Low energy requirement for involuntary muscles. 
FunctionsVoluntary muscles are controlled under command or own will. Involuntary muscles cannot be controlled under command or own will. 
Found in They are found in organs like the tongue, muscles of the mid-ear. They are attached to the bones. They are found in organs like alimentary tracts, glands, blood vessels and are not attached to bones. 

What are Voluntary Muscles?

When you are controlling your muscles on your own will, such muscles are usually categorized as Voluntary muscles of the body. These muscles are found in organs that are attached to the bone structure. The tendons attach them and carry out all of the external movement of the human body. They have a long cylindrical shape where their cell contents are multinucleated. Its nucleus is present in the periphery. 

Voluntary muscles contribute to 40% of human body weight and carry out the basic functions necessary for the body. Its striated appearance occurs because of its unbranched muscle fibers that are crossed with red and white lines. These muscle fibers are further covered with unique cell membranes are known as myeloma or also called sarcolemma. The cell membrane sarcolemma in voluntary muscles is thick and connects each muscle fiber in the body to one another. 

It is no wonder inside the human body that each muscle fiber is connected as a basic requirement of the human body and interacts with each other either through blood vessels or nerves. The nucleus of the voluntary muscles is present in the periphery of the body, which controls the action of these muscles. This process is also called the somatic nervous system. 

What are Involuntary Muscles?

Involuntary muscles cause contraction, which is controlled by the autonomous nervous system and doesn’t function on your command or will. These muscles are found in organs of the body like the stomach, blood vessels, and respiratory tracts. Involuntary muscles contain in the body in the form of smooth muscles due to their origin mainly in the thin lining of walls of organs. 

Involuntary muscles also have a cell membrane covering their muscle fibers that take part in connecting all the muscle fibers and enable interaction. This cell membrane is called myolemma or sarcolemma. Another example of involuntary muscle is a cardiac muscle which is known for its different structure and functions compared to other involuntary muscles. There are differences in the contraction for involuntary muscles, like contraction in cardiac muscles is different from skeletal muscles, and its action potentiality is generated through electrical stimulation. 

Involuntary muscles are involved in the movements of the internal organs and also paves the path for different fluids and food to pass through for the process of digestive systems. These muscles require low energy for movement and are usually small in shape and size compared to other muscles like voluntary muscles. 

Main Differences Between Voluntary Muscles and Involuntary Muscles

  1. The nucleus of voluntary muscles is present in the periphery, whereas, in terms of involuntary muscles, the nucleus is present at the center. 
  2. The sarcolemma present in the voluntary muscles is thick, whereas, in terms of involuntary muscles, it is thinner. 
  3. The shape of voluntary muscles is long and in a cylindrical shape, whereas involuntary muscles are small muscles with a shape like a spindle. 
  4. Contraction takes place both in voluntary and involuntary muscles. However, the process of contraction in voluntary muscles is fast and requires high energy, whereas involuntary muscles contraction is slow and requires less energy. 
  5. Voluntary muscles, after movement, get tired and require rest after a period, whereas involuntary muscles do not get tired easily and work for longer periods without a break. 

Conclusion

The muscles are a very important part of the human body that enables some of the basic functions of the body structure, like movement both internally and externally. Such actions are required by bodies for survival reasons as contraction and expansion to involve in the process of movement. Important muscles like voluntary and involuntary muscles are the reasons why humans tend to move easily. Moreover, they also protect the body from external shock, which is equally important to survive. These are the factors why muscles are important for mankind.

References

  1. https://onlinelibrary.wiley.com/doi/abs/10.1002/bsl.729
  2. https://www.tandfonline.com/doi/abs/10.1080/00207144.2011.622213
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