Which type of muscle is characterized by crossed striations?

The type of muscle characterized by crossed striations is cardiac muscle. Cardiac muscle tissue is found exclusively in the heart and is responsible for pumping blood throughout the body. The presence of crossed striations in cardiac muscle is due to its unique structural organization. Cardiac muscle fibers are branched and interconnected, forming a network that enables coordinated contractions essential for effective heart function.

The striations arise from the regular arrangement of actin and myosin filaments within the muscle fibers, which provide the appearance of stripes when viewed under a microscope. This organized structure is vital for the synchronized contraction of the heart, allowing it to efficiently pump blood. The presence of intercalated discs, which connect adjacent cardiac muscle cells, further contributes to the functionality of cardiac muscle by facilitating communication and electrical conduction between cells.

In contrast, smooth muscle does not have striations, as its fibers lack the organized arrangement of myofilaments found in cardiac and skeletal muscle. Skeletal muscle, while also striated, is characterized by its voluntary control and multi-nucleated fibers, distinct from the involuntary contractions of cardiac muscle. Fibrous muscle is not a recognized type of muscle tissue in the context of this question.