2-15. TYPES OF MUSCLE TISSUES
See figure 2-3 for the three types of muscle tissue.
a. Skeletal Muscle Tissue. The cells (muscle fibers) of skeletal
muscle tissue are long and cylindrical and have numerous nuclei. The arrangement of the
cellular contents is very specific and results in a striated appearance when viewed with
the microscope. This type of muscle tissue is found mainly in the skeletal muscles.
b. Cardiac Muscle Tissue. The cells (muscle fibers) of cardiac
muscle tissue are short, branched, contain one nucleus, and are striated. This tissue
makes up the myocardium (wall) of the heart.
c. Smooth Muscle Tissue. The cells (muscle fibers) of smooth muscle
tissue are spindle-shaped, contain one nucleus, and are not striated. Smooth muscle tissue
is generally found in the walls of hollow organs such as the organs of the digestive and
respiratory systems, the blood vessels, the ureters, urinary bladder, urethra, and
reproductive ducts.
