Question

what structure appears in cardiac muscle but not in skeletal muscle?
a) sarcomeres
b) intercalated discs
c) perimysium
d) myofibrils

Explanation:

• Sarcomeres: Present in both cardiac and skeletal muscle as the basic contractile unit.
• Intercalated discs: Unique to cardiac muscle, facilitating cell - to - cell communication and electrical coupling.
• Perimysium: A connective tissue layer found in skeletal muscle (surrounding fascicles), not a unique feature of cardiac muscle.
• Myofibrils: Present in both cardiac and skeletal muscle, composed of sarcomeres.

Answer:

B. Intercalated discs