Question

While observing cardiac muscle under the microscope for the first time, Jennifer noticed lines running perpendicular to the direction of the muscle. These lines are called ....

Answer 1

The right answer is intercalated discs.

Step-by-step explanation:

If you observe cardiac muscles under a microscope, the first feature that appears is Intercalated discs. Cardiac muscles contains heart muscle cells which are called as cardiomyocytes which are linked by these discs to perform a single functional organ.

Intercalated discs helps in harmonizing the contraction of cardiac tissues.