Question

Which of the following is true about cardiac muscle?

• A. Spindle shaped
• B. Large central nucleus
• C. No gap junctions
• D. Arranged in sheets

Hint:

Recall where the nucleus sits in a cardiac myocyte versus a skeletal fibre.

Answer 1

The Correct Option is B

Step 1: Cardiac muscle has distinctive features that separate it from both skeletal and smooth muscle.

Step 2: Cardiac myocytes are short, branching cylindrical cells, each typically with one (sometimes two) centrally placed nucleus. This matches the option of a large central nucleus.

Step 3: Why the others are wrong: spindle shaped describes smooth muscle, not cardiac. Cardiac muscle is rich in gap junctions within the intercalated discs, which allow rapid electrical coupling, so the no gap junctions option is false. Cardiac fibres branch and interconnect rather than being arranged in flat sheets.

Step 4: Therefore the correct statement is that cardiac muscle has a large central nucleus.