Muscle Tissue

Muscle Tissue well-vascularized tissues that are responsible for most types of body movement. Muscle cells possess myofilaments, elaborate versions of the actin and myosin filaments that bring about movement or contraction in all cell types. There are three kinds of muscle tissue: skeletal, cardiac, and smooth.

  Skeletal muscle is packaged by connective tissue sheets into organs called skeletal muscles that are attached to the bones of the skeleton. causing body movements. Skeletal muscle cells, also called muscle fibers, are long, cylindrical cells that contain many nuclei.

Cardiac muscle is found only in the wall of the heart. Its contractions help propel blood through the blood vessels to all parts of the body. Like skeletal muscle cells, cardiac muscle cells are striated. However, they differ structurally in that cardiac cells : are uninucleate and are branching cells that fit together tightly at unique junctions called intercalated discs

 Smooth muscle is so named because its cells have no visible striations. Individual smooth muscle cells are spindle shaped and contain one centrally located nucleus Smooth muscle is found mainly in the walls of hollow organs other than the heart (digestive and urinary tract organs, uterus, and blood vessels). It acts to squeeze substances through these organs by alternately contracting and relaxing.

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