Question

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

Accepted Answer

Animal tissue is divided into epithelial tissue, muscular tissue, connective and nervous tissue. Muscular tissue is made of muscle cells. Each muscle cell is tubular and elongated, called muscle fibre. A muscle fibre is made of contractile protein. Contraction and relaxation in muscle fibre are caused by these proteins. The cytoplasm of muscle fibres is called sarcoplasm, and its endoplasmic reticulum is called the sarcoplasmic reticulum (SR). Muscular tissue is of three types:-

Striated muscle

Smooth muscle

Cardiac muscle

Striated muscle:- Its cells are long cylindrical fibres that are enclosed in a membrane called sarcolemma. Its muscles move according to our will, so are called voluntary muscles. The muscles which are attached to the skeleton system are called striated muscles. Its fibres are multinucleated. Its myofibrils are arranged in alternate dark and light bands.

Fig. Striated muscle

Smooth muscle:- Its muscle cells are spindle-shaped and are not enclosed by sarcolemma. The myofibrils do not show light and dark bands and look smooth. These muscle fibres do not move according to our will, i.e. it contains involuntary muscles. It is present in the alimentary canal and blood vessels.

Fig. Smooth muscle

Cardiac muscle:- They show both longitudinal and transverse striations, i.e. it shows characters of both striated and smooth muscles. These fibres do not work according to our will. They are involuntary in function. Its fibres are branched and multinucleated. These fibres are present only in the heart region of the body.

Fig. Cardiac muscle

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

Important Questions on Model Test Paper 3

Learn and Prepare for any exam you want !