Muscle tissue is composed of cells that have the ability to shorten or contract in order to produce movement of the body parts Properties of Muscular Tissue Contractibility – Ability of muscle cells to shorten Excitability – Muscle tissue responds to a stimulus delivered from neuron or hormone Extensibility – Ability to be stretched Elasticity – Ability to recoil back to its original length after being stretched Structure of Muscular tissue Muscular tissues are bundled together and surrounded by tough connective tissue known as epimysium The tissue made of many muscle fibres (myocytes) Fascicles are surrounded by a protective layer known as perimysium Muscle fibres are composed of numerous fine myofibrils Muscle fibres can contract and relax Muscles take part in locomotion and movements 1. Skeletal muscle Skeletal muscles are attached to the skeleton They are also known as striated muscles because of the presence of alternate patterns of light and dark bands These light and dark bands are highly organized structures of actin, myosin, and proteins. These add to the contractility and extensibility of the muscles Skeletal muscles are also known as voluntary muscles Skeletal muscle tissue is composed of long cells called muscle fibers that have multinucleated They play a vital role in everyday activities 2. Smooth muscle These muscle cells are spindle-shaped with a single nucleus Smooth muscle is found in the walls of hollow organs throughout the body These are non-striated, involuntary muscles controlled by nervous system The actin and myosin filaments are very thin and arranged randomly, hence no striations It stimulates the contractility of the digestive, urinary, reproductive systems and blood vessels 3. Cardiac Muscle Tissue Cardiac muscle tissue is present only in the heart They are single celled and uninucleated The cells of the cardiac muscles known as the cardiomyocytes are striated These are involuntary muscles and the heart pumps the blood through cardiac contractions Muscle cells, unique junctions called intercalated discs (gap junctions) Intercalated discs are the major portal for cardiac cell to cell communication