There are three kinds of muscle tissue: skeletal, smooth, and cardiac.
Skeletal Muscle
Skeletal muscles are highly organized with cells lying parallel to each other. Skeletal muscles are voluntary and striated in nature that allow movement of an organism by the deliberate generation of force.
Skeletal muscle fibers are the longest muscle fibers and have stripes on their surface. These stripes are called striations. These muscle fibers are cylindrical, multinucleate in nature. Their function is to produce locomotion that is voluntary in nature. They are also responsible for many facial expressions.
The skeletal muscle striations are large enough to align the nuclei to the sides of the fibers, which are known as peripherally located nuclei. The banding pattern of the striations reflects the alignment of the myofilament fibers. Skeletal muscle is striated, multinucleate, and involuntary.
Smooth Muscle
Smooth muscle is named because it does not have any striations. The individual smooth muscle fibers are spindle shaped and contain a centrally located nucleus.
Smooth muscle is found in the walls of the hollow organs. As an involuntary muscle, it propels substances along the internal passageways. By alternating contraction and relaxation, it helps in the movement of food substances, urine, blood, and birth.
Cardiac Muscle
Cardiac muscle is found in the walls of the heart. Although cardiac muscle is involuntary in nature, it is structurally different from smooth muscle. It is generally uninucleate, but is striated.
The striations are fitted together with unique junctions called intercalated disks, specialized junctions that help in the transmission of electrical impulses so the heart can beat in a steady rhythm.
The involuntary contraction of cardiac muscle is coordinated by the intercalated disks, so the entire heart beats in a controlled, uniform manner, ensuring that blood is efficiently pumped from the chambers.
Cardiac muscle
Cardiac muscle is striated, similar to skeletal muscle, but beats involuntarily. The cells beat in unison as a result of unique gap junctions between the muscle cells.