Which of the following describes one difference between skeletal muscles and cardiac muscles?
A. Skeletal muscles are found in the viscera whereas cardiac muscles are found in the cranium
B. Cardiac muscles contain intercalated discs, whereas skeletal muscles do not
C. Cardiac muscles are voluntary, whereas skeletal muscles are involuntary
D. Skeletal muscles are autorhythmic, whereas cardiac muscles are not
Cardiac muscles have intercalated discs that enable them to contract in a coordinated manner. Skeletal muscles do not have intercalated discs, as their contraction is under voluntary control and does not require the same level of synchronization seen in the involuntary contraction of cardiac muscle.
Therefore, the Correct Answer is B.