1. Muscle Tissue

2. Three Types of Muscle Tissue Skeletal or Striated Muscle –Makes up all muscles that are attached to bones –Contractions allow the organism to move Smooth Muscle –Found in the walls of hollow muscular organs, parts of the trachea and bronchioles and the walls of blood vessels –Various functions, depending on the organ Cardiac Muscle –Found in the walls of the heart –Contractions move blood through the chambers of the heart, or to the major arteries leaving the heart.

3. Skeletal Muscle The elongated fibers of skeletal muscle are striated. The striations are dark and light stripes along the muscle cell due to the arrangement of the protein filaments, or myofilaments within the muscle fiber. Contractions of skeletal muscle can be regulated by conscious control, therefore, it is considered to be voluntary. A skeletal muscle cell is multinucleated, which means it has more than one nucleus. Skeletal muscle fibers are surrounded by, and bundle by several layers of connective tissue.

4. Skeletal Muscle

5. Smooth Muscle Smooth muscle fibers are spindle-shaped and smaller than skeletal and cardiac muscle fibers. Each cell contains only one nucleus Fibers are not arranged in an orderly manner and thus are not striated Individual smooth muscle fibers are surrounded by connective tissue, but the fibers are not bundled like skeletal muscle Smooth muscle is involuntary and contractions are controlled subconsciously by the brain

6. Smooth Muscle

7. Cardiac Muscle Cardiac muscle fibers are striated Fibers contain one or two nuclei Fibers are branched and are smaller in diameter than skeletal muscle Fibers are connected by zig-zaggety membrane specializations called intercalated discs Each muscle fiber is surrounded by connective tissue, but the fibers are not bundled. Cardiac muscle contraction are controlled subconsciously by the brain, which makes it involuntary

8. Cardiac Muscle