Read the assertion and reason carefully to mark the correct option out of the options given below:-

Assertion: Cardiac muscle look like syncytium but histologically it is not syncytium

Reason: Cardiac muscle fibers branch and interdigitate, but each is a complete unit surrounded by cell membrane with a centrally located single nucleus

Key Points

• Syncytium refers to a single cell mass containing numerous nuclei, usually caused due to fusion of cells.
• Muscles are divided into 3 major classes:

Important Points

• Cardiac muscle look like syncytium but histologically it is not syncytium: Assertion is TRUE
  • It does look like a syncytium with multiple nucleus.
  • From the above table we see that cardiac muscles are uninucleate.
  • Thus, it cannot be a syncytium histologically.
• Reason is TRUE
  • Cardiac muscle fibers are joined end-to-end by flat zig-zag junctions called intercalated discs.
  • The fibers are interconnected by oblique bridges, forming a network.
  • This gives the look of a syncytium, but they are actually individual fibers.
  • They are also branched muscle fibers with interdigitation.
  • Each fibre has a centrally located nucleus and covered by a special covering sarcolemma.