Question

Cardiac muscles are

• A. Smooth, spindle-shaped, and involuntary
• B. Striated, syncytial, and involuntary
• C. Striated, syncytial, and voluntary
• D. Striated, cross-connected, and involuntary

Answer 1

The correct option is D

Striated, cross-connected, and involuntary

The correct option is D:

Explanation of the correct option:

1. Cardiac Muscles are long, branched, and cylindrical muscle fibers present in the wall of the heart.
2. Alternative light and dark f bands are present and thus appear to be striated.
3. They are involuntary in nature.
4. Oblique bridges and intercalated discs are present in between and thus are cross-connected with each other.

Explanation of the incorrect option:

Option A:

Cardiac muscles are not spindle-shaped instead they are branched cylindrical muscles.

Option B:

1. There is only a single nucleus present in one cell of the cardiac muscle.
2. Thus cardiac muscles are not syncytial(a condition where many nuclei are present in a single cell.

Option C:

1. Cardiac muscles are involuntary that is we don't have any control over them.
2. Therefore cardiac muscles are not voluntary and syncytial.

Final Answer: Hence cardiac muscles are Striated, cross-connected, and involuntary.