Difference between Voluntary and Involuntary Muscles

The muscular system is mainly responsible for permitting movement of the body, maintaining the body’s posture, and circulation of blood cells throughout the body. This organ system includes more than 700 muscles and makes up about 40 percent of the total body’s weight. These muscles are attached to bones, blood vessels and other internal organs of our body and are mainly composed of skeletal muscles, tissue, tendons, and nerves.

Every movement in our body are the results of muscle contraction and are found in every organ, including the blood vessels heart, and digestive organs. In these organs, muscles function by transferring the substances throughout the body. There are three types of muscle and are mainly classified based on their movements and structures.

  1. Skeletal Muscles: It is a form of striated muscle tissues and is mainly found attached to bones by the tendons.
  2. Smooth Muscles: These muscles are found inside of organs like the blood vessels, stomach, and intestines. These muscles help in the movements of substances through the organs.
  3. Cardiac Muscles: These muscles are found only in the heart, and are mainly responsible for pumping blood throughout the body.

Voluntary Muscles

Voluntary muscles are long, multinucleated cells, containing sarcomeres arranged into bundles. These muscles are composed of cylindrical fibers and are usually attached to bones and the skin. They play an important role in allowing the body to move by contracting and relaxing and their actions are mainly under the control of the somatosensory nervous system. These voluntary muscles include skeletal muscles.

  • Skeletal muscles

It is one of the major types of muscle which is under the voluntary control of the somatic nervous system. It mainly refers to multiple bundles of cells and muscle fibers. These muscles are involved in the muscle contraction, signaling pathways, etc.

Involuntary Muscles

Involuntary muscles are striated and branched in the case of cardiac muscle. The actions of involuntary muscles are mainly controlled by the autonomic nervous system in the body. These involuntary muscles include smooth muscles and cardiac muscles.

  • Smooth muscles

These muscles are found in the internal walls of the intestines, stomach, uterus, and blood vessels. These muscles help in pushing food molecules along the length of the alimentary canal, controlling the internal diameter of the blood vessels, and contracting the uterus during labour and childbirth.

  • Cardiac muscles

These muscles are unique and are found only in the heart. These muscles help in maintaining the proper blood circulation throughout the body by maintaining the heartbeat.

Let us learn more in detail about the differences between voluntary and involuntary muscles to have a clear idea about this muscular system.

Difference between Voluntary and Involuntary Muscles

Voluntary Muscles

Involuntary Muscles

Long, cylindrical and unbranched shaped muscles.

Small and spindle-shaped muscles.

These muscles are multinucleated.

These muscles are uni nucleated.

Found attached to bones.

Found in the walls of internal organs.

High energy requirement.

Low energy requirement.

Presence of the nucleus at the rim.

Presence of the nucleus at the center.

Has a thick Sarcolemma

Has a thin Sarcolemma

Actions are mainly under the control of the somatic nervous system.

Actions are mainly under the control of the Autonomic nervous system.

Powerful and rapid contractions.

Rhythmic and slow contractions.

Require high energy.

Require low energy.

Get tired and need rest at regular intervals.

Do not get tired and can work continuously.

These muscles are under the control of our will.

These muscles not under the control of our will.

Involved in the movement of body parts and the locomotion of the body.

Involved in the internal movements of the organs, aiding the passage of fluids and food in the digestive system.

Diaphragm, pharynx, abdominal wall tongue, middle ear muscles, muscles under the skin are few examples of Voluntary Muscles

Urogenital tracts, alimentary tracts, respiratory tracts, ducts of glands, blood vessels, are few examples of Involuntary Muscles

Stay tuned with BYJU’S to learn more about the muscular systems.


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