Question

Define muscular tissue. Classify and explain different types of muscles with the help of suitable diagrams.

Answer 1

Muscle tissue is one of the four basic tissues found in animals. It is a type of contractile tissue composed of muscle cells. These cells are also described as muscle fibers because of their large size and elongated nature. Muscle fibers are categorized into the following three types on the basis of their structure, location, and function:

(i) Striated muscles:


Striated muscle fibers are also called voluntary or skeletal muscles. These muscles are elongated, unbranched and multinucleated. Moreover, these muscles are attached to the bones and assist in body movements.

(ii) Smooth muscles:


Smooth muscles are also called involuntary or unstriated muscles. These muscles are present as a fusiform elongated sheet. A single nucleus is present in these muscles and myofibrils (contractile threads) are present longitudinally in these cells.

(iii) Cardiac muscles:

Cardiac muscles are extensively branched and these branches join to form a compact network. Light and dark bands along with a single nucleus can be observed in the cells of these muscles. These muscles are found in the heart.