Which tissue is non-striated?

• A. Skeletal muscle tissue
• B. Cardiac muscle tissue
• C. Smooth muscle tissue
• D. Dense connective tissue

Answer: (C)

Striations in muscle tissue come from the organized arrangement of sarcomeres along each muscle fiber. Non-striated means there’s no visible banding, indicating the absence of those repeating sarcomeres. Smooth muscle tissue fits this, because its contractile units aren’t arranged into the orderly sarcomeres you see in skeletal or cardiac muscle. Smooth muscle is found in the walls of hollow organs and blood vessels, and it contracts involuntarily with spindle-shaped cells that typically have a single nucleus.

In contrast, skeletal muscle shows clear striations due to its highly organized sarcomeric structure and is usually under voluntary control. Cardiac muscle also appears striated but is involuntary and features intercalated discs that connect cells. Dense connective tissue isn’t muscle at all; it’s made mainly of densely packed collagen fibers and does not have muscle fibers or sarcomeres, so it lacks striations.