Question

Which is true of both cardiac and smooth muscle? a. striated b. multinucleated c. involuntary control d. spindle-shaped cells

Short answer

The correct answer is c. involuntary control, as both cardiac and smooth muscle exhibit involuntary control, meaning their contraction and relaxation are not under conscious control.

Step-by-step solution

Eliminate options based on features exclusive to either cardiac or smooth muscle.

Since cardiac muscle is striated, while smooth muscle is non-striated, option (a) cannot be correct. On the other hand, both cardiac and smooth muscle cells contain a single central nucleus, making option (b) incorrect as well.

Identify features that both cardiac and smooth muscle share.

Both cardiac and smooth muscle exhibit involuntary control, i.e., their contraction and relaxation are not under conscious control. This matches with option (c). Option (d) states spindle-shaped cells, which are a characteristic of smooth muscle but not cardiac muscle.

Choose the correct option.

After analyzing the features of both cardiac and smooth muscle, we can conclude that the only true similarity in the given options is involuntary control, which corresponds to option (c). So, the correct answer is: c. involuntary control