Muscles
Muscle is a specialized tissue derived from the mesoderm. Muscles contribute approximately 40-50% of the body weight of a human adult. While looking into the properties of muscles it can be observed that they are excitable, contractile, extensible, and elastic.
Muscles are classified based on different criteria, including location, appearance, and nature of regulation of their activities. There are mainly three types of muscles that are identified based on their location; skeletal muscles, visceral muscles, and cardiac muscles.
- Skeletal muscles are closely associated with the skeletal components of the body and exhibit a striped appearance under the microscope, hence referred to as striated muscles. Skeletal muscles are under the voluntary control of the nervous system and are primarily involved in locomotion and changes in body postures.
- Visceral muscles are located in the inner walls of hollow visceral organs like the alimentary canal and reproductive tract. Visceral muscles have a smooth appearance as they do not exhibit striations, therefore also known as smooth muscles or non-striated muscles. The activities of visceral muscles are not entirely controlled by the nervous system which classifies them as involuntary muscles. It assists in functions such as the transportation of food through the digestive tract and gametes through the genital tract.
- Cardiac muscles in simple words are the muscles of the heart, and they derive their name from their association. Cardiac muscle cells are organized in a branching pattern to form the cardiac muscle tissue. They appear striated, in nature, which means their activities are not directly controlled by the nervous system.
NCERT Notes for Class 11 Biology Chapter 17: Locomotion and Movement
NCERT and CBSE Notes for Class 11 Biology Chapter 17: Locomotion and Movement: The given article is a detailed introduction to the class 11 chapter “Locomotion and Movement”. The article discusses all the important topics and their related sub-topics which include muscles, types of muscles, muscle contraction, skeletal system, and a brief illustration of different types of bones present in the human body.
Notes on Locomotion and Movement of NCERT Class 11 The article also looks into the structure of contractile protein and its functioning. A bunch of frequently asked questions are also included in this article for better understanding.