Answer: Cardiac muscle.
- A Skeletal muscle
- B Smooth muscle
- C Cardiac muscle
- D Both skeletal and smooth
Correct answer: C. Cardiac muscle
Explanation: Cardiac muscle is found only in the heart. It is striated (like skeletal) but involuntary (like smooth). Cardiac muscle cells have intercalated discs for electrical coupling and never fatigue under normal conditions.
A sarcomere (Z line to Z line): during contraction the I band and H zone shorten as thin filaments slide over thick, while the A band stays the same length. Image: SlothMcCarty, CC BY-SA 3.0, via Wikimedia Commons.
Concept context
Types of movement, muscle contraction, skeletal system, joints, and disorders. Important for Class 11 and NEET.