Which one of the following are the INCORRECT statements:
(i) 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.
(ii) 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.
(iii) Striated muscles are under the involuntary control of the nervous system; they are known as involuntary muscles too. They are primarily involved in locomotory actions and changes of body postures.
(iv) Cardiac muscles are striated. They are voluntary in nature as the nervous system does control their activities directly.
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) - Both (iii) and (iv) statements.
Based on their location, three types of muscles are identified : (i) Skeletal (ii) Visceral and (iii) Cardiac.
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 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 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.