Which type of muscle tissue contains intercalated discs that help electrically and mechanically couple adjacent cells?

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

Answer: (A)

Verified step by step guidance

1. Step 1: Understand the types of muscle tissue: skeletal, cardiac, and smooth muscle, each with distinct structural and functional characteristics.
2. Step 2: Recall that intercalated discs are specialized structures found only in cardiac muscle tissue, which facilitate both electrical and mechanical coupling between adjacent cells.
3. Step 3: Recognize that skeletal muscle lacks intercalated discs and is characterized by multinucleated fibers with voluntary control, while smooth muscle also lacks intercalated discs and is involuntary with spindle-shaped cells.
4. Step 4: Note that dense regular connective tissue is not a muscle tissue but a type of connective tissue, so it does not contain intercalated discs.
5. Step 5: Conclude that the presence of intercalated discs is a defining feature of cardiac muscle, enabling synchronized contraction of the heart muscle.