Understanding muscles and their properties

Hyderabad: This article is in continuation to the previous articles focusing on Locomotion and Movement. In this article, we will discuss different kinds of muscles in the body. Muscular movement • Movement of our limbs, jaws, tongue, etc., requires muscular movement. • The contractile property of muscles is effectively used for locomotion and other movements […]

Hyderabad: This article is in continuation to the previous articles focusing on Locomotion and Movement. In this article, we will discuss different kinds of muscles in the body.

Muscular movement

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• Movement of our limbs, jaws, tongue, etc., requires muscular movement.

• The contractile property of muscles is effectively used for locomotion and other movements by human beings and majority of multicellular organisms.

• Locomotion requires a perfect coordinated activity of muscular, skeletal and neural systems.

Muscle

• The cilia and flagella are the outgrowths of the cell membrane.

• Flagellar movement helps in the swimming of spermatozoa, maintenance of water current in the canal system of sponges and in locomotion of Protozoans like Euglena.

• Muscle is a specialised tissue of mesodermal origin.
• About 40-50 per cent of the body weight of a human adult is contributed by muscles.
• They have special properties like excitability, contractility, extensibility and elasticity.
• Muscles have been classified using different criteria, namely location, appearance and nature of regulation of their activities.
• Based on their location, three types of muscles are identified: (i) Skeletal (ii) Visceral and (iii) Cardiac.
Skeletal muscles
• Skeletal muscles are closely associated with the skeletal components of the body.
• They have a striped appearance under the microscope and hence are called striated muscles.
• As their activities are under the voluntary control of the nervous system, they are known as voluntary muscles too.
• They are primarily involved in locomotory actions and changes of body postures.
Visceral muscles
• Visceral muscles are located in the inner walls of hollow visceral organs of the body like the alimentary canal, reproductive tract, etc.

• They do not exhibit any striation and are smooth in appearance. Hence, they are called smooth muscles (nonstriated muscle).

• Their activities are not under the voluntary control of the nervous system and are, therefore, known as involuntary muscles.

• They assist, for example, in the transportation of food through the digestive tract and gametes through the genital tract.

Cardiac muscles

• As the name suggests, cardiac muscles are the muscles of heart.

• Many cardiac muscle cells assemble in a branching pattern to form a cardiac muscle.

• Based on appearance, cardiac muscles are striated.

• They are involuntary in nature as the nervous system does not control their activities directly.

To be continued…
By Dr. Modala Mallesh
Subject Expert

Palem, Nakrekal, Nalgonda

9989535675