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| Muscular Tissue |
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| The muscular tissue is a tissue that is capable of bringing about different types of movements in the body. It is one of the highly specialized animal tissues. It is a derivative of mesoderm. The muscular tissue exhibits a unique property called contractibility. It is the capacity of the cells to exhibit regular contractions and relaxations. Hence, it is also known as contractile tissue. Muscular tissue exhibits the following characteristic features. |
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 The cells are always elongated and are therefore described as muscle fibres. |
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 Each muscle fibre usually has a limiting membrane called sarcolemma, in addition to the cell membrane. |
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 The cytoplasm in the muscle fibres is specialised for contraction and is known as sarcoplasm. |
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 The sarcoplasm always encloses minute, microscopic contractile units called myofibrils. |
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 The myofibrils are in turn composed of ultra microscopic units called myofilaments. The myofilaments are of two types. |
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| a) Thin filaments, which are about 50 A0 in diameter and are composed of a simple protein, called actin. |
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| b) Thick filaments, which are about 100 A0 in diameter and are composed of a simple protein called myosin. |
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 The muscular tissue has a direct blood supply (vascular) |
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 The muscle fibres have very limited capacity to undergo cell division. |
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| The muscular tissue is classified into the following three types |
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| 1. Smooth muscle |
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| 2. Striated muscle |
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| 3. Cardiac muscle. |
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