Which statements describe cardiac muscle tissue?

Which statements describe cardiac muscle tissue?

• A. This tissue is branched and contains intercalated discs
• B. This tissue is under autonomic nervous system
• C. This tissue is striated
• D. All of the answers are correct

Answer: (D)

Cardiac muscle tissue is designed to pump efficiently as a unit. The cells are branched and connected by intercalated discs, which include gap junctions that allow ions to pass quickly between cells, producing synchronized contractions. The tissue is striated, reflecting the organized sarcomeres that generate force. It is under autonomic nervous system control, meaning heart rate and force are modulated by sympathetic and parasympathetic inputs, even though the contraction originates from the heart’s own pacemaker activity. All of these features apply to cardiac muscle, so this description correctly identifies the tissue. For contrast, skeletal muscle isn’t branched and lacks intercalated discs and is under voluntary control, while smooth muscle is non-striated and organized differently.

Cardiac muscle tissue is designed to pump efficiently as a unit. The cells are branched and connected by intercalated discs, which include gap junctions that allow ions to pass quickly between cells, producing synchronized contractions. The tissue is striated, reflecting the organized sarcomeres that generate force. It is under autonomic nervous system control, meaning heart rate and force are modulated by sympathetic and parasympathetic inputs, even though the contraction originates from the heart’s own pacemaker activity. All of these features apply to cardiac muscle, so this description correctly identifies the tissue. For contrast, skeletal muscle isn’t branched and lacks intercalated discs and is under voluntary control, while smooth muscle is non-striated and organized differently.